阅读说明：本技术 有机化合物、发光元件、发光装置、电子设备及照明装置 (Organic compound, light-emitting element, light-emitting device, electronic device, and lighting device ) 是由 栗原美树 原朋香 吉住英子 渡部智美 木户裕允 濑尾哲史 于 2018-06-12 设计创作，主要内容包括：提供一种新颖的有机化合物。换言之,提供一种在提高元件特性及可靠性上有效的新颖的有机化合物。该有机化合物由通式(G1)表示并包含苯并呋喃并嘧啶骨架或苯并噻吩并嘧啶骨架。在通式(G1)中,Q表示氧或硫。另外,α表示取代或未取代的碳原子数为6至13的亚芳基,n表示0至4的整数。另外,A<Sup>1</Sup>表示包含芳基或杂芳基的碳原子数为6至100的基。另外,R<Sup>1</Sup>至R<Sup>4</Sup>分别独立地表示氢、取代或未取代的碳原子数为1至6的烷基、取代或未取代的碳原子数为3至7的环烷基和取代或未取代的碳原子数为6至13的芳基中的任一个。另外,A<Sup>2</Sup>表示稠环。(In other words, a novel organic compound effective in improving element characteristics and reliability is provided, which is represented by general formula (G1) and includes a benzofuropyrimidine skeleton or a benzothienopyrimidine skeleton, in general formula (G1), Q represents oxygen or sulfur, α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, n represents an integer of 0 to 4, and A represents 1 Represents a group having 6 to 100 carbon atoms including an aryl group or a heteroaryl group. In addition, R 1 To R 4 Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A 2 Represent fused rings.)

1. An organic compound represented by the general formula (G1):

wherein:

q represents oxygen or sulfur;

α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms;

n represents an integer of 0 to 4;

A¹represents a group having 6 to 100 carbon atoms including an aryl group or a heteroaryl group;

R¹to R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms;

A²represents a substituted or unsubstituted fused aromatic hydrocarbon ring or a substituted or unsubstituted pi-electron rich fused heteroaromatic ring.

2. An organic compound represented by the general formula (G2):

wherein:

q represents oxygen or sulfur;

α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms;

n represents an integer of 0 to 4;

A¹represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted heteroaryl group having 6 to 100 total carbon atoms;

R¹to R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms;

A²represents a substituted or unsubstituted fused aromatic hydrocarbon ring or a substituted or unsubstituted pi-electron rich fused heteroaromatic ring.

3. The organic compound according to claim 2, wherein the organic compound is a compound represented by formula (I),

wherein the organic compound is represented by the general formula (G3):

4. an organic compound represented by the general formula (G4):

wherein:

q represents oxygen or sulfur;

α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms;

n represents an integer of 0 to 4;

A¹represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted heteroaryl group having 6 to 100 total carbon atoms;

R¹to R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms;

A³represents a substituted or unsubstituted fused aromatic hydrocarbon ring or a substituted or unsubstituted pi-electron rich fused heteroaromatic ring.

5. An organic compound represented by the general formula (G5):

wherein:

q represents oxygen or sulfur;

α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms;

n represents an integer of 0 to 4;

A¹represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted heteroaryl group having 6 to 100 total carbon atoms;

R¹to R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms;

A⁴represents a substituted or unsubstituted fused aromatic hydrocarbon ring or a substituted or unsubstituted pi-electron rich fused heteroaromatic ring.

6. The organic compound according to claim 5, wherein the organic compound is a compound represented by formula (I),

wherein the organic compound is represented by the general formula (G6):

7. the organic compound of claim 2, wherein a¹A skeleton having a hole-transporting property.

8. The organic compound according to claim 7, wherein the skeleton having a hole-transporting property is any one of a diarylamino group, a fused aromatic hydrocarbon ring, and a pi-electron-rich fused heteroaromatic ring.

9. The method of claim 2An organic compound wherein A¹Is a substituted or unsubstituted fused aromatic hydrocarbon ring or a substituted or unsubstituted pi-electron rich fused heteroaromatic ring.

10. The organic compound of claim 2, wherein a¹Is a substituted or unsubstituted fused heteroaromatic ring having any one of a dibenzothiophene skeleton, a dibenzofuran skeleton and a carbazole skeleton.

11. The organic compound of claim 2, wherein a²Is a condensed ring having any one of a substituted or unsubstituted dibenzothiophene skeleton, a substituted or unsubstituted dibenzofuran skeleton, a substituted or unsubstituted carbazole skeleton, a substituted or unsubstituted naphthalene skeleton, a substituted or unsubstituted fluorene skeleton, a substituted or unsubstituted triphenylene skeleton, a substituted or unsubstituted phenanthrene skeleton, and a substituted or unsubstituted naphthalene skeleton.

12. The organic compound according to claim 2, wherein the organic compound is a compound represented by formula (I),

wherein A in the general formulae (G1) to (G6)¹And A²Are each independently of the formula (A)¹-1) to (A)¹-17) of:

wherein:

R^A1to R^A11Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

13. The organic compound according to claim 2, wherein α in the general formulae (G1) to (G6) is any one of the general formulae (Ar-1) to (Ar-18):

14. the organic compound according to claim 2, wherein the organic compound is a compound represented by formula (I),

wherein the organic compound is represented by structural formula (100), (101), or (102):

15. a light-emitting element comprising the organic compound according to claim 2.

16. A light-emitting element comprising an EL layer between a pair of electrodes,

wherein the EL layer comprises the organic compound according to claim 2.

17. A light-emitting element comprising an EL layer between a pair of electrodes,

wherein the EL layer includes a light emitting layer,

and the light-emitting layer includes the organic compound according to claim 2.

18. A light emitting device comprising:

the light-emitting element according to claim 15; and

at least one of a transistor and a substrate.

19. An electronic device, comprising:

the light emitting device of claim 18; and

at least one of a microphone, a camera, an operation button, an external connection portion, and a speaker.

20. An illumination device, comprising:

the light-emitting element according to claim 15; and

at least one of a housing, a cover, and a support table.

Technical Field

One embodiment of the present invention relates to a compound having a benzofuran or benzothienopyrimidine skeleton with fused rings directly bonded. In addition, one embodiment of the present invention relates to a light-emitting element including the compound. One embodiment of the present invention relates to a display device, an electronic device, and a lighting device each including the light-emitting element.

One embodiment of the present invention relates to an organic compound, a light-emitting element, a light-emitting device, an electronic device, and a lighting device. However, one embodiment of the present invention is not limited to the above-described technical field. That is, one embodiment of the present invention relates to an object, a method, a manufacturing method, or a driving method. Additionally, one embodiment of the present invention relates to a process, machine, product, or composition. Specifically, a semiconductor device, a display device, a liquid crystal display device, and the like can be given as examples.

Background

Since a light-emitting element (also referred to as an organic EL element) including an EL layer between a pair of electrodes has characteristics such as thinness and lightness in weight, high-speed response to an input signal, and low power consumption, a display using the light-emitting element is expected to be used as a next-generation flat panel display.

In the light-emitting element, when a voltage is applied between a pair of electrodes, electrons and holes injected from the respective electrodes are recombined in the EL layer, and a light-emitting substance (organic compound) included in the EL layer is brought into an excited state, and light is emitted when the excited state returns to a ground state. Further, as the kind of excited state, a singlet excited state (S) may be mentioned^*) And triplet excited state (T)^*) In this case, light emission from a singlet excited state is referred to as fluorescence, and light emission from a triplet excited state is referred to as phosphorescence. In addition, in this light-emitting element, the statistical generation ratio of the singlet excited state and the triplet excited state is considered to be S^*:T^*1: 3. An emission spectrum obtained from a light-emitting substance is peculiar to the light-emitting substance, and by using different kinds of organic compounds as the light-emitting substance, light-emitting elements exhibiting various emission colors can be obtained.

In order to improve the element characteristics of such a light-emitting element, improvement of an element structure, development of a material, and the like have been actively performed (for example, see patent document 1).

[ reference documents ]

[ patent document ]

[ patent document 1] Japanese patent application laid-open No. 2010-182699

Disclosure of Invention

In the development of a light-emitting element, an organic compound used for the light-emitting element is very important in terms of improving the characteristics of the light-emitting element. Accordingly, it is an object of one embodiment of the present invention to provide a novel organic compound. That is, a novel organic compound effective in improving element characteristics and reliability is provided. In addition, it is an object of one embodiment of the present invention to provide a novel organic compound which can be used for a light-emitting element. Further, it is an object of one embodiment of the present invention to provide a novel organic compound which can be used for an EL layer of a light-emitting element. Another object of one embodiment of the present invention is to provide a novel light-emitting element which uses the novel organic compound of one embodiment of the present invention and has high efficiency and high reliability. Further, it is an object of one embodiment of the present invention to provide a novel light-emitting device, a novel electronic device, or a novel lighting device. Note that the description of the above object does not hinder the existence of other objects. An embodiment of the present invention need not achieve all of the above objectives. Objects other than those mentioned above will be apparent from and may be derived from the description of the specification, drawings, claims and the like.

One embodiment of the present invention is an organic compound containing a benzofuropyrimidine skeleton or benzothienopyrimidine skeleton represented by the general formula (G1).

[ chemical formula 1]

In the general formula (G1), Q represents oxygen or sulfur, α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and n represents an integer of 0 to 4, and A¹Represents a group having 6 to 100 carbon atoms including an aryl group or a heteroaryl group. In addition, R¹To R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A²Represent fused rings.

Another embodiment of the present invention is an organic compound represented by general formula (G2).

[ chemical formula 2]

In the general formula (G2), Q represents oxygen or sulfur, α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and n representsAn integer of 0 to 4. In addition, A¹Represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted heteroaryl group having 6 to 100 total carbon atoms. In addition, R¹To R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A²Represent fused rings.

Another embodiment of the present invention is an organic compound represented by general formula (G3).

[ chemical formula 3]

In the general formula (G3), Q represents oxygen or sulfur, α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and n represents an integer of 0 to 4, and A¹Represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted heteroaryl group having 6 to 100 total carbon atoms. In addition, R¹To R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A²Represent fused rings.

Another embodiment of the present invention is an organic compound represented by general formula (G4).

[ chemical formula 4]

In the general formula (G4), Q represents oxygen or sulfur, α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and n represents an integer of 0 to 4, and A¹Represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted hetero group having 6 to 100 total carbon atomsAnd (4) an aryl group. In addition, R¹To R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A³Represent fused rings.

In the general formula (G4), A³Preferred is a condensed aromatic hydrocarbon group having a naphthalene skeleton, a fluorene skeleton, a phenanthrene skeleton, a triphenylene skeleton, or the like.

Another embodiment of the present invention is an organic compound represented by general formula (G5).

[ chemical formula 5]

In the general formula (G5), Q represents oxygen or sulfur, α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and n represents an integer of 0 to 4, and A¹Represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted heteroaryl group having 6 to 100 total carbon atoms. In addition, R¹To R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A⁴Represent fused rings.

In the general formula (G5), A⁴Preferred is a condensed aromatic hydrocarbon group having a naphthalene skeleton, a fluorene skeleton, a phenanthrene skeleton, a triphenylene skeleton, or the like.

Another embodiment of the present invention is an organic compound represented by general formula (G6).

[ chemical formula 6]

In the general formula (G6), Q represents oxygen or sulfur, α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and nRepresents an integer of 0 to 4. In addition, A¹Represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted heteroaryl group having 6 to 100 total carbon atoms. In addition, R¹To R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A⁴Represent fused rings.

Further, as shown in the general formulae (G3), (G4), and (G6), the condensed ring is preferably bonded to the 8-position of the benzofuro [3,2-d ] pyrimidine skeleton or benzothieno [3,2-d ] pyrimidine skeleton in order to obtain a long-lived light-emitting element.

Further, the general formulae (G1) to (G6) are characterized in that A¹Comprises a skeleton having a hole-transporting property. The skeleton having a hole-transporting property is preferably any of a diarylamino group, a fused aromatic hydrocarbon ring, and a pi-electron-rich fused heteroaromatic ring.

Further, in the general formulae (G2) to (G6), A¹Preferred are substituted or unsubstituted fused aromatic hydrocarbon rings or substituted or unsubstituted pi-electron rich fused heteroaromatic rings. In particular, in terms of hole transporting property, A¹Preferably a pi-electron-rich fused heteroaromatic ring, more preferably a substituted or unsubstituted fused heteroaromatic ring containing any one of a dibenzothiophene skeleton, a dibenzofuran skeleton and a carbazole skeleton.

On the other hand, the other features of the general formulae (G1) to (G6) are that A²、A³And A⁴The fused rings of (a) are each independently a substituted or unsubstituted fused aromatic hydrocarbon ring or a substituted or unsubstituted pi-electron rich fused heteroaromatic ring. Specifically, A²、A³And A⁴Each independently is a condensed ring containing any one of a substituted or unsubstituted dibenzothiophene skeleton, a substituted or unsubstituted dibenzofuran skeleton, a substituted or unsubstituted carbazole skeleton, a substituted or unsubstituted naphthalene skeleton, a substituted or unsubstituted fluorene skeleton, a substituted or unsubstituted triphenylene skeleton, and a substituted or unsubstituted phenanthrene skeleton. Note that the above-mentioned condensed aromatic hydrocarbon ringUnsaturated fused aromatic hydrocarbon rings are preferred. The unsaturated fused aromatic hydrocarbon ring is preferably substituted or unsubstituted³The carbon atoms of the bond constitute a fused aromatic hydrocarbon ring, specifically a naphthalene ring, a triphenylene ring, a phenanthrene ring, or the like.

In the general formulae (G1) to (G6), A¹、A²、A³And A⁴Are each independently of the formula (A)¹-1) to the general formula (A)¹-17).

[ chemical formula 7]

In the general formula (A)¹-1) to the general formula (A)¹In-17), R^A1To R^A11Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

In the general formulae (G1) to (G6), α is an organic compound represented by any one of the general formulae (Ar-1) to (Ar-17).

[ chemical formula 8]

Another embodiment of the present invention is an organic compound represented by structural formula (100), structural formula (101), or structural formula (102).

[ chemical formula 9]

Another embodiment of the present invention is a light-emitting element including the organic compound according to the above-described embodiment of the present invention. Note that the present invention also includes a light-emitting element including a host material in addition to the above-described organic compound.

Another embodiment of the present invention is a light-emitting element including the organic compound according to the above-described embodiment of the present invention. In addition, one embodiment of the present invention also includes a light-emitting element in which an EL layer between a pair of electrodes and a light-emitting layer in the EL layer include the organic compound according to one embodiment of the present invention. In addition to the light-emitting element, a light-emitting device including a transistor, a substrate, or the like is also included in the scope of the invention. Also, in addition to the above-described light-emitting device, an electronic apparatus and a lighting device including a microphone, a camera, an operation button, an external connection portion, a housing, a cover, a stand, a speaker, or the like are included in the scope of the invention.

In addition, the scope of one embodiment of the present invention includes not only a light-emitting device including a light-emitting element but also a lighting device including a light-emitting device. Therefore, the light-emitting device in this specification refers to an image display device or a light source (including a lighting device). In addition, the light-emitting device further includes the following modules: a module in which a light emitting device is mounted with a connector such as a Flexible Printed Circuit (FPC) or a Tape Carrier Package (TCP); a module having a printed wiring board provided in an end portion of the TCP; or a module in which an IC (integrated circuit) is directly mounted on a light-emitting element by a Chip On Glass (COG) method.

One embodiment of the present invention can provide a novel organic compound. That is, one embodiment of the present invention can provide a novel organic compound which is effective in improving element characteristics. In addition, one embodiment of the present invention can provide a novel organic compound which can be used for a light-emitting element. In addition, one embodiment of the present invention can provide a novel organic compound which can be used for an EL layer of a light-emitting element. Further, a novel light-emitting element which uses the novel organic compound according to one embodiment of the present invention and has high efficiency and high reliability can be provided. In addition, a novel light-emitting device, a novel electronic apparatus, or a novel lighting device can be provided. Note that the description of the above effects does not hinder the existence of other effects. An embodiment of the present invention does not necessarily need to achieve all of the above-described effects. Effects other than the above-described effects are apparent from and can be derived from the description of the specification, the drawings, the claims, and the like.

Drawings

Fig. 1A to 1E show the structure of a light emitting element.

Fig. 2A to 2C illustrate a light emitting device.

Fig. 3A and 3B show a light-emitting device.

Fig. 4A to 4G illustrate electronic apparatuses.

Fig. 5A to 5C illustrate electronic apparatuses.

Fig. 6A and 6B show an automobile.

Fig. 7A to 7D show a lighting device.

Fig. 8 shows a lighting device.

FIG. 9 is a drawing showing an organic compound represented by the structural formula (100)¹H-NMR spectrum.

Fig. 10A and 10B show an ultraviolet-visible absorption spectrum and an emission spectrum of the organic compound represented by the structural formula (100).

Fig. 11 shows an MS spectrum of the organic compound represented by structural formula (100).

FIG. 12 is a drawing showing an organic compound represented by the structural formula (101)¹H-NMR spectrum.

Fig. 13A and 13B show an ultraviolet-visible absorption spectrum and an emission spectrum of the organic compound represented by structural formula (101).

Fig. 14 shows an MS spectrum of the organic compound represented by structural formula (101).

FIG. 15 is a view of an organic compound represented by the structural formula (102)¹H-NMR spectrum.

Fig. 16A and 16B show an ultraviolet-visible absorption spectrum and an emission spectrum of the organic compound represented by the structural formula (102).

Fig. 17 shows an MS spectrum of the organic compound represented by structural formula (102).

Fig. 18 shows a light-emitting element.

Fig. 19 shows current density-luminance characteristics of the light-emitting elements 1,2, and 3.

Fig. 20 shows voltage-luminance characteristics of the light-emitting elements 1,2, and 3.

Fig. 21 shows luminance-current efficiency characteristics of the light-emitting elements 1,2, and 3.

Fig. 22 shows voltage-current characteristics of the light-emitting elements 1,2, and 3.

Fig. 23 shows emission spectra of the light-emitting element 1, the light-emitting element 2, and the light-emitting element 3.

Fig. 24 shows the reliability of the light-emitting element 1, the light-emitting element 2, and the light-emitting element 3.

Fig. 25 shows current density-luminance characteristics of the light-emitting element 4 and the comparative light-emitting element 5.

Fig. 26 shows voltage-luminance characteristics of the light-emitting element 4 and the comparative light-emitting element 5.

Fig. 27 shows luminance-current efficiency characteristics of the light-emitting element 4 and the comparative light-emitting element 5.

Fig. 28 shows voltage-current characteristics of the light-emitting element 4 and the comparative light-emitting element 5.

Fig. 29 shows emission spectra of the light-emitting element 4 and the comparative light-emitting element 5.

Fig. 30 shows the reliability of the light-emitting element 4 and the comparative light-emitting element 5.

FIG. 31 is a view of an organic compound represented by the structural formula (103)¹H-NMR spectrum.

FIG. 32 is a drawing showing an example of an organic compound represented by the structural formula (116)¹H-NMR spectrum.

Fig. 33 shows current density-luminance characteristics of the light-emitting elements 6 and 7.

Fig. 34 shows voltage-luminance characteristics of the light-emitting elements 6 and 7.

Fig. 35 shows luminance-current efficiency characteristics of the light-emitting elements 6 and 7.

Fig. 36 shows voltage-current characteristics of the light-emitting elements 6 and 7.

Fig. 37 shows emission spectra of the light-emitting elements 6 and 7.

Fig. 38 shows the reliability of the light emitting elements 6 and 7.

Fig. 39 shows the current density-luminance characteristics of the light emitting element 8.

Fig. 40 shows voltage-luminance characteristics of the light emitting element 8.

Fig. 41 shows luminance-current efficiency characteristics of the light emitting element 8.

Fig. 42 shows voltage-current characteristics of the light emitting element 8.

Fig. 43 shows a graph of the emission spectrum of the light emitting element 8.

Detailed Description

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following description, and the mode and the details thereof may be changed into various forms without departing from the spirit and the scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments shown below.

For convenience of understanding, the positions, sizes, ranges, and the like of the respective components shown in the drawings and the like do not indicate actual positions, sizes, ranges, and the like. Accordingly, the disclosed invention is not necessarily limited to the positions, sizes, ranges, etc., disclosed in the drawings and the like.

Note that in this specification and the like, when the structure of the invention is described with reference to the drawings, symbols indicating the same parts may be used in common in different drawings.

(embodiment mode 1)

In this embodiment, an organic compound according to an embodiment of the present invention will be described.

One embodiment of the present invention is an organic compound containing a benzofuropyrimidine skeleton or benzothienopyrimidine skeleton represented by the general formula (G1).

[ chemical formula 10]

In the general formula (G1), Q represents oxygen or sulfur, α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and n represents an integer of 0 to 4, and A¹Represents a group having 6 to 100 carbon atoms including an aryl group or a heteroaryl group. In addition, R¹To R⁴Each independently represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atomsAny of a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A²Represent fused rings.

In the general formula (G1), by reacting a condensed ring (A)²) Directly bonded to the benzene side of the benzofuropyrimidine skeleton or benzothienopyrimidine skeleton, thermophysical properties are improved, and reliability of the light-emitting element is improved.

Another embodiment of the present invention is an organic compound represented by general formula (G2).

[ chemical formula 11]

In the general formula (G2), Q represents oxygen or sulfur, α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and n represents an integer of 0 to 4, and A¹Represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted heteroaryl group having 6 to 100 total carbon atoms. In addition, R¹To R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A²Represent fused rings.

In the general formula (G2), by reacting a condensed ring (A)²) Directly bonded to the benzene side of the benzofuropyrimidine skeleton or benzothienopyrimidine skeleton, thermophysical properties are improved, and reliability of the light-emitting element is improved.

Another embodiment of the present invention is an organic compound represented by general formula (G3).

[ chemical formula 12]

In the general formula (G3), Q represents oxygen or sulfur, and α represents substituted or unsubstitutedAn unsubstituted arylene group having 6 to 13 carbon atoms, and n represents an integer of 0 to 4. In addition, A¹Represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted heteroaryl group having 6 to 100 total carbon atoms. In addition, R¹To R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A²Represent fused rings.

As shown in the general formula (G3), when a condensed ring is bonded to the 8-position of a benzofuropyrimidine skeleton or benzothienopyrimidine skeleton, a material in which the amount of impurities such as halides that adversely affect the characteristics and reliability of the device is reduced can be easily synthesized, and hence the cost of raw materials is also dominant. In other words, a light-emitting element having a long lifetime can be obtained. In addition, A of the formula (G4)³And A of the formula (G6)⁴The same effect is also obtained.

Further, as shown in the general formula (G3), bonding a condensed ring to the 8-position of a benzofuropyrimidine skeleton or benzothienopyrimidine skeleton can not only improve electrochemical stability and film quality, but also realize a high T1 level. In addition, A of the formula (G4)³And A of the formula (G6)⁴The same effect is also obtained.

In the general formula (G3), n is preferably 1 or 2.

In the general formula (G3), by reacting a condensed ring (A)²) Directly bonded to the benzene side of the benzofuropyrimidine skeleton or benzothienopyrimidine skeleton, thermophysical properties are improved, and reliability of the light-emitting element is improved.

Another embodiment of the present invention is an organic compound represented by general formula (G4).

[ chemical formula 13]

In the general formula (G4), Q represents oxygen or sulfur. In addition, the first and second substrates are,α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and n represents an integer of 0 to 4¹Represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted heteroaryl group having 6 to 100 total carbon atoms. In addition, R¹To R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A³Represent fused rings.

In the general formula (G4), A³Preferred is a condensed aromatic hydrocarbon group having a naphthalene skeleton, a fluorene skeleton, a phenanthrene skeleton, a triphenylene skeleton, or the like.

In addition, in the general formula (G4), A¹Preferred are substituted or unsubstituted pi-electron rich fused heteroaromatic rings comprising a dibenzothiophene skeleton, a dibenzofuran skeleton or a carbazole skeleton.

In the general formula (G4), n is preferably 1 or 2.

In the general formula (G4), by reacting a condensed ring (A)³) Directly bonded to the benzene side of the benzofuropyrimidine skeleton or benzothienopyrimidine skeleton, thermophysical properties are improved, and reliability of the light-emitting element is improved.

Another embodiment of the present invention is an organic compound represented by general formula (G5).

[ chemical formula 14]

In the general formula (G5), Q represents oxygen or sulfur, α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and n represents an integer of 0 to 4, and A¹Represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted heteroaryl group having 6 to 100 total carbon atoms. In addition, R¹To R⁴Each independently represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted ring having 3 to 7 carbon atomsAny one of an alkyl group and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A⁴Represent fused rings.

In the general formula (G5), A⁴Preferred is a condensed aromatic hydrocarbon group having a naphthalene skeleton, a fluorene skeleton, a phenanthrene skeleton, a triphenylene skeleton, or the like.

In addition, in the general formula (G5), A¹Preferred are substituted or unsubstituted pi-electron rich fused heteroaromatic rings comprising a dibenzothiophene skeleton, a dibenzofuran skeleton or a carbazole skeleton.

In the general formula (G5), n is preferably 1 or 2.

In the general formula (G5), by reacting a condensed ring (A)⁴) Directly bonded to the benzene side of the benzofuropyrimidine skeleton or benzothienopyrimidine skeleton, thermophysical properties are improved, and reliability of the light-emitting element is improved.

Another embodiment of the present invention is an organic compound represented by general formula (G6).

[ chemical formula 15]

In the general formula (G6), Q represents oxygen or sulfur, α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and n represents an integer of 0 to 4, and A¹Represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted heteroaryl group having 6 to 100 total carbon atoms. In addition, R¹To R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A⁴Represent fused rings.

In the general formula (G6), A⁴Preferred is a pi-electron-rich fused heteroaromatic ring containing a dibenzothiophene skeleton, a dibenzofuran skeleton, a carbazole skeleton, or the like.

In addition, in the general formula (G6), A⁴Preferably to benzofuropyrimidinesThe 8-position of the pyridine skeleton or benzothienopyrimidine skeleton.

In addition, in the general formula (G6), A¹Preferred are substituted or unsubstituted pi-electron rich fused heteroaromatic rings comprising a dibenzothiophene skeleton, a dibenzofuran skeleton or a carbazole skeleton.

In the general formula (G6), n is preferably 1 or 2.

In the general formula (G6), by reacting a condensed ring (A)⁴) Directly bonded to the benzene side of the benzofuropyrimidine skeleton or benzothienopyrimidine skeleton, thermophysical properties are improved, and reliability of the light-emitting element is improved.

Here, one embodiment of the present invention is characterized in that A is in the general formula (G1) to the general formula (G6)¹Comprises a skeleton having a hole-transporting property. The compounds represented by the general formulae (G1) to (G6) each have a structure derived from benzofuro [3,2-d]Pyrimidine skeleton or benzothieno [3,2-d ]]Electron transport properties of pyrimidine skeleton. By adding a skeleton having a hole-transporting property to this compound, a bipolar compound having stability to both holes and electrons can be provided. In addition, when a bipolar compound is used as a main body of a light-emitting element, a recombination region of carriers can be increased, and the life of the light-emitting element can be prolonged. Examples of the skeleton having a hole-transporting property include a diarylamino group, a fused aromatic hydrocarbon ring, and a pi-electron-rich fused heteroaromatic ring.

From the above viewpoint, in the above general formulae (G2) to (G6), A¹Preferred are substituted or unsubstituted fused aromatic hydrocarbon rings or substituted or unsubstituted pi-electron rich fused heteroaromatic rings. In particular, in terms of hole transporting property, A¹Preferably a pi-electron-rich fused heteroaromatic ring, more preferably a substituted or unsubstituted fused heteroaromatic ring containing any one of a dibenzothiophene skeleton, a dibenzofuran skeleton and a carbazole skeleton. Such a fused heteroaromatic ring containing a five-membered ring can achieve higher hole transporting property and chemical stability.

In particular, R in the organic compound of the present embodiment is preferable in terms of easy synthesis and raw material cost¹To R⁴Are both hydrogen, in which case the organic compounds each have a relatively low molecular weight and are suitable for vacuum evaporation.

On the other hand, the other features of the general formulae (G1) to (G6) are that A²、A³And A⁴The fused rings of (a) are each independently a substituted or unsubstituted fused aromatic hydrocarbon ring or a substituted or unsubstituted pi-electron rich fused heteroaromatic ring. Among the condensed rings, aromatic condensed rings are preferably used because chemical stability directly affecting the lifetime of the light-emitting element can be obtained by resonance stabilization and the thermophysical properties (heat resistance) are also improved.

Specifically, the general formulae (G1) to (G6) are characterized by A²、A³And A⁴Each independently is a condensed ring containing any one of a substituted or unsubstituted dibenzothiophene skeleton, a substituted or unsubstituted dibenzofuran skeleton, a substituted or unsubstituted carbazole skeleton, a substituted or unsubstituted naphthalene skeleton, a substituted or unsubstituted fluorene skeleton, a substituted or unsubstituted triphenylene skeleton, and a substituted or unsubstituted phenanthrene skeleton.

Note that the fused aromatic hydrocarbon ring is preferably an unsaturated fused aromatic hydrocarbon ring having a small ring tension from the viewpoint of chemical stability. The unsaturated fused aromatic hydrocarbon ring is preferably substituted or unsubstituted³The carbon atoms of the bonds constitute a fused aromatic hydrocarbon ring, specifically a naphthalene ring, a triphenylene ring or a phenanthrene ring.

In the above general formulae (G1) to (G6), A¹、A²、A³And A⁴Each independently represents a compound represented by the formula (A)¹-1) to the general formula (A)¹-17).

[ chemical formula 16]

In the general formula (A)¹-1) to the general formula (A)¹In-17), R^A1To R^A11Each independently represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, andany one of substituted or unsubstituted aryl groups having 6 to 13 carbon atoms.

In the general formulae (G1) to (G6), α is any one of the general formulae (Ar-1) to (Ar-18).

[ chemical formula 17]

In the general formulae (G1) to (G6), when any of a substituted or unsubstituted diarylamino group having 6 to 13 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, a substituted or unsubstituted monocyclic saturated hydrocarbon group having 3 to 20 carbon atoms, and a substituted or unsubstituted polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms has a substituent, examples of the substituent include an alkyl group having 1 to 7 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group, a cycloalkyl group having 5 to 7 carbon atoms such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, an 8, 9, 10-trinorborneol (trinorbornanyl) group, and an aryl group having 6 to 12 carbon atoms such as a phenyl group, a naphthyl group, and a biphenyl group.

Specific examples of the monocyclic saturated hydrocarbon group having 3 to 20 carbon atoms in the general formulae (G1) to (G6) include cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, 2-methylcyclohexyl, cyclooctyl, cyclononyl, cyclodecyl, and cycloeicosyl.

Specific examples of the polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms in the general formulae (G1) to (G6) include 8, 9, 10-trinorborneol, decalin, and adamantyl.

Specific examples of the aryl group having 6 to 13 carbon atoms in the general formulae (G1) to (G6) include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a mesityl group, an o-biphenyl group, an m-biphenyl group, a p-biphenylyl group, a 1-naphthyl group, a 2-naphthyl group, a fluorenyl group, and a 9, 9-dimethylfluorenyl group.

Specific examples of the alkyl group having 1 to 7 carbon atoms in the general formulae (G1) to (G6) include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl, isopentyl, sec-pentyl, tert-pentyl, neopentyl, hexyl, isohexyl, 3-methylpentyl, 2-ethylbutyl, 1, 2-dimethylbutyl, 2, 3-dimethylbutyl, and n-heptyl.

Next, a specific structural formula of the organic compound according to one embodiment of the present invention is shown below. Note that the present invention is not limited to these formulae.

[ chemical formula 18]

[ chemical formula 19]

[ chemical formula 20]

[ chemical formula 21]

[ chemical formula 22]

In addition, the organic compounds represented by the above structural formulae (100) to (150) are examples of the organic compounds represented by the general formulae (G1) to (G6). The organic compound of one embodiment of the present invention is not limited thereto.

Next, an example of a method for synthesizing an organic compound represented by general formula (G1) according to one embodiment of the present invention will be described.

[ chemical formula 23]

In the general formula (G1), Q represents oxygen or sulfur, α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and n represents an integer of 0 to 4, and A¹Represents a group having 6 to 100 carbon atoms including an aryl group or a heteroaryl group. In addition, R¹To R⁴Each independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, A²Represent fused rings.

Method for synthesizing organic Compound represented by general formula (G1)

The organic compound represented by the above general formula (G1) is a benzofuropyrimidine derivative or benzothienopyrimidine derivative, and various reactions can be employed as a method for synthesizing the same. For example, the organic compound represented by the general formula (G1) can be synthesized in the following simple synthesis scheme.

For example, as shown in synthesis scheme (a), a halogen compound (a1) comprising a substituted or unsubstituted benzofuropyrimidine skeleton or benzothienopyrimidine skeleton is reacted with a condensed ring (a2) comprising a substituted or unsubstituted aryl group.

[ chemical formula 24]

At this time, as shown in the synthesis scheme (B), a dihalogen compound (B1) containing a substituted or unsubstituted benzofuropyrimidine skeleton or benzothienopyrimidine skeleton is reacted with a fused ring boronic acid compound (a2) containing a substituted or unsubstituted aryl group to obtain an intermediate (D1), and then the intermediate (D1) may also be reacted with a substituted or unsubstituted fused ring boronic acid compound (B2).

[ chemical formula 25]

Further, as shown in synthesis scheme (C), after obtaining intermediate (D2) through reaction with aryl boronic acid compound (C1) substituted with halogen, intermediate (D3) may be obtained through reaction with substituted or unsubstituted fused ring boronic acid compound (C2), and intermediate (D3) may also be reacted with substituted or unsubstituted fused ring boronic acid compound (B2). In addition, B¹To B⁴Each represents boric acid, a borate ester, a cyclic triol borate, or the like. Further, as the cyclic triol borate, a lithium salt, a potassium salt, or a sodium salt may be used.

[ chemical formula 26]

In addition, in the synthesis schemes (a), (b) and (c), X represents a halogen group or a trifluoromethanesulfonate group, Q represents oxygen or sulfur, A¹Represents a substituted or unsubstituted aryl group having 6 to 100 total carbon atoms or a substituted or unsubstituted heteroaryl group having 6 to 100 total carbon atoms, A²Represents a condensed ring, R¹To R⁴Each independently represents any one of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, α represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and n represents an integer of 0 to 4.

Since various of the above-mentioned compounds (a1), (a2), (B1), (B2), (C1) and (C2) are commercially available or can be synthesized, a variety of benzofuropyrimidine derivatives or benzothienopyrimidine derivatives represented by the general formula (G1) can be synthesized. In other words, the compound of one embodiment of the present invention has a wide variety of characteristics.

In addition, in the synthesis schemes (a), (b) and (c), when the suzuki-miyaura cross-coupling reaction using a palladium catalyst is performed, it is preferable that X represents a halogen group or a trifluoromethanesulfonate group, and the halogen is iodine, bromine or chlorine. In this reaction, a palladium compound such as tris (dibenzylideneacetone) dipalladium (0) or palladium (II) acetate, and a ligand such as bis (1-adamantyl) -n-butylphosphine or 2' - (dicyclohexylphosphino) acetophenone vinyl ketal can be used. Further, an organic base such as sodium tert-butoxide, an inorganic base such as cesium fluoride, tripotassium phosphate, and potassium carbonate, or the like can be used. As the solvent, toluene, xylene, benzene, tetrahydrofuran, mesitylene, diglyme, or the like can be used. The reagent and the like that can be used in the reaction are not limited to these.

The above description is an example of a method for synthesizing a benzofuran pyrimidine derivative or benzothienopyrimidine derivative as a compound according to one embodiment of the present invention. However, the present invention is not limited to this example, and any other synthesis method may be employed.

Further, by using the organic compound according to one embodiment of the present invention, a light-emitting element, a light-emitting device, an electronic device, or a lighting device with high light-emitting efficiency can be realized. Further, a light-emitting element, a light-emitting device, an electronic appliance, or a lighting device with low power consumption can be realized.

In this embodiment, one embodiment of the present invention is described. In addition, in other embodiments, other embodiments of the present invention will be described. Note that one embodiment of the present invention is not limited thereto. That is, various embodiments of the invention are described in this embodiment and other embodiments, and thus one embodiment of the invention is not limited to a specific embodiment.

The structure described in this embodiment can be combined with any of the structures described in the other embodiments as appropriate.

(embodiment mode 2)

In this embodiment, a light-emitting element including the organic compound described in embodiment 1 will be described with reference to fig. 1A to 1E.

Basic Structure of light emitting element

First, a basic structure of the light-emitting element is described. Fig. 1A shows a light-emitting element having an EL layer including a light-emitting layer between a pair of electrodes. Specifically, the light-emitting element has a structure in which the EL layer 103 is sandwiched between the first electrode 101 and the second electrode 102.

Fig. 1B shows a light-emitting element having a stacked structure (series structure) in which a plurality of (two layers in fig. 1B) EL layers (103a and 103B) are provided between a pair of electrodes, and a charge generation layer 104 is interposed between the EL layers. The light-emitting element having the series structure can realize a light-emitting device which can be driven at low voltage and has low power consumption.

The charge generation layer 104 has the following functions: when a voltage is applied to the first electrode 101 and the second electrode 102, electrons are injected into one EL layer (103a or 103b) and holes are injected into the other EL layer (103b or 103 a). Thus, in fig. 1B, when a voltage is applied so that the potential of the first electrode 101 is higher than that of the second electrode 102, electrons are injected from the charge generation layer 104 into the EL layer 103a, and holes are injected into the EL layer 103B.

In addition, from the viewpoint of light extraction efficiency, the charge generation layer 104 preferably has a light-transmitting property with respect to visible light (specifically, the charge generation layer 104 has a visible light transmittance of 40% or more). In addition, the charge generation layer 104 functions even if its conductivity is lower than that of the first electrode 101 or the second electrode 102.

Fig. 1C shows a stacked-layer structure of the EL layer 103 of the light-emitting element according to the embodiment of the present invention. In this case, the first electrode 101 is used as an anode. The EL layer 103 has a structure in which a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115 are sequentially stacked over the first electrode 101. In the case where a plurality of EL layers are provided as in the series structure shown in fig. 1B, the EL layers are also stacked from the anode side as described above. In addition, when the first electrode 101 is a cathode and the second electrode 102 is an anode, the lamination order is reversed.

The light-emitting layer 113 in the EL layers (103, 103a, and 103b) has a structure in which a luminescent material and a plurality of materials are appropriately combined to obtain fluorescent light emission and phosphorescent light emission which show a desired light emission color. The light-emitting layer 113 may have a stacked structure of different emission colors. In this case, the light-emitting substance or the other substance used for each light-emitting layer of the stack may be different materials. Further, a structure in which different emission colors are obtained from the plurality of EL layers (103a and 103B) shown in fig. 1B may be employed. In this case, the light-emitting substance or the other substance used for each light-emitting layer may be different materials.

In the light-emitting element according to the embodiment of the present invention, for example, by employing an optical microcavity resonator (microcavity) structure in which the first electrode 101 shown in fig. 1C is a reflective electrode and the second electrode 102 is a transflective electrode, light obtained from the light-emitting layer 113 in the EL layer 103 can be resonated between the electrodes, and light obtained from the second electrode 102 can be enhanced.

When the first electrode 101 of the light-emitting element is a reflective electrode having a stacked structure of a conductive material having reflectivity and a conductive material having translucency (transparent conductive film), optical adjustment can be performed by adjusting the thickness of the transparent conductive film. Specifically, the adjustment is preferably performed as follows: the distance between the first electrode 101 and the second electrode 102 is about m λ/2 (note that m is a natural number) with respect to the wavelength λ of light obtained from the light-emitting layer 113.

In order to amplify the desired light (wavelength: λ) obtained from the light-emitting layer 113, it is preferable to adjust the following: the optical distance from the first electrode 101 to the region (light-emitting region) where desired light of the light-emitting layer 113 can be obtained and the optical distance from the second electrode 102 to the region (light-emitting region) where desired light of the light-emitting layer 113 can be obtained are both (2m '+ 1) λ/4 (note that m' is a natural number). Note that the "light-emitting region" described here refers to a recombination region of holes and electrons in the light-emitting layer 113.

By performing the optical adjustment, the spectrum of the specific monochromatic light obtainable from the light-emitting layer 113 can be narrowed, and light emission with high color purity can be obtained.

In addition, in the above case, strictly speaking, the optical distance between the first electrode 101 and the second electrode 102 can be said to be the total thickness from the reflective region in the first electrode 101 to the reflective region in the second electrode 102. However, since it is difficult to accurately determine the position of the reflective region in the first electrode 101 or the second electrode 102, the above-described effects can be sufficiently obtained by assuming that any position of the first electrode 101 and the second electrode 102 is the reflective region. In addition, strictly speaking, the optical distance between the first electrode 101 and the light-emitting layer that can obtain desired light can be said to be the optical distance between the reflective region in the first electrode 101 and the light-emitting region in the light-emitting layer that can obtain desired light. However, since it is difficult to accurately determine the position of the reflective region in the first electrode 101 or the light-emitting region in the light-emitting layer from which desired light can be obtained, the above-described effects can be sufficiently obtained by assuming that an arbitrary position in the first electrode 101 is the reflective region and an arbitrary position in the light-emitting layer from which desired light can be obtained is the light-emitting region.

The light emitting element shown in fig. 1C has a microcavity structure, and thus can extract light of different wavelengths (monochromatic light) even with the same EL layer. Thus, separate coating (e.g., R, G, B) is not required to obtain different emission colors. Thereby, high resolution is easily achieved. In addition, it may be combined with a colored layer (color filter). Further, the emission intensity in the front direction having a specific wavelength can be enhanced, and low power consumption can be achieved.

The light-emitting element shown in fig. 1E is an example of the light-emitting element having the series structure shown in fig. 1B, and has a structure in which three EL layers (103a, 103B, and 103c) are stacked with charge generation layers (104a and 104B) interposed therebetween, as shown in the drawing. The three EL layers (103a, 103b, 103c) include light emitting layers (113a, 113b, 113c), respectively, and the light emission color of each light emitting layer can be freely selected. For example, the light emitting layer 113a may emit blue, the light emitting layer 113b may emit one of red, green, and yellow, and the light emitting layer 113c may emit blue. In addition, for example, the light emitting layer 113a may emit red, the light emitting layer 113b may emit one of blue, green, and yellow, and the light emitting layer 113c may emit red.

In the light-emitting element according to the above-described embodiment of the present invention, at least one of the first electrode 101 and the second electrode 102 is a light-transmitting electrode (such as a transparent electrode or a transflective electrode). In which the electrode having light-transmitting property is a transparent electrodeIn this case, the transparent electrode has a visible light transmittance of 40% or more. When the light-transmitting electrode is a transflective electrode, the reflectance of visible light of the transflective electrode is 20% or more and 80% or less, and preferably 40% or more and 70% or less. In addition, the resistivity of these electrodes is preferably 1 × 10^-2Omega cm or less.

In the light-emitting element according to the above-described embodiment of the present invention, when one of the first electrode 101 and the second electrode 102 is a reflective electrode, the reflectance of the reflective electrode with respect to visible light is 40% or more and 100% or less, and preferably 70% or more and 100% or less. In addition, the resistivity of the electrode is preferably 1 × 10^-2Omega cm or less.

Concrete structure and manufacturing method of light emitting element

Next, a specific structure and a manufacturing method of a light-emitting element according to an embodiment of the present invention will be described with reference to fig. 1A to 1E. Here, a light-emitting element having the series structure and the microcavity structure shown in fig. 1B will be described with reference to fig. 1D. In the light-emitting element having a microcavity structure shown in fig. 1D, a first electrode 101 is formed as a reflective electrode, and a second electrode 102 is formed as a transflective electrode. Thus, the electrode can be formed by using a desired electrode material alone or by using a plurality of electrode materials in a single layer or a stacked layer. After the EL layer 103b is formed, the second electrode 102 is formed by selecting a material in the same manner as described above. The electrode may be formed by a sputtering method or a vacuum deposition method.

< first electrode and second electrode >

As materials for forming the first electrode 101 and the second electrode 102, the following materials may be appropriately combined if the functions of the two electrodes can be satisfied. For example, metals, alloys, conductive compounds, mixtures thereof, and the like can be suitably used. Specific examples thereof include an In-Sn oxide (also referred to as ITO), an In-Si-Sn oxide (also referred to as ITSO), an In-Zn oxide, and an In-W-Zn oxide. In addition to the above, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), and alloys appropriately combining these metals may be mentioned. In addition to the above, elements belonging to group 1 or group 2 of the periodic table (for example, rare earth metals such as lithium (Li), cesium (Cs), calcium (Ca), strontium (Sr), europium (Eu), and ytterbium (Yb)), alloys in which these are appropriately combined, graphene, and the like can be used.

In the case where the first electrode 101 is an anode in the light-emitting element shown in fig. 1D, the hole injection layer 111a and the hole transport layer 112a of the EL layer 103a are sequentially stacked on the first electrode 101 by a vacuum evaporation method. After the EL layer 103a and the charge generation layer 104 are formed, the hole injection layer 111b and the hole transport layer 112b of the EL layer 103b are sequentially stacked on the charge generation layer 104 in the same manner as described above.

< hole injection layer and hole transport layer >

The hole injection layers (111, 111a, 111b) are layers for injecting holes from the first electrode 101 or the charge generation layer 104 of the anode into the EL layers (103, 103a, 103b), and include a material having a high hole injection property.

Examples of the material having a high hole-injecting property include transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide. In addition to the above, phthalocyanine-based compounds such as phthalocyanine (abbreviated as H) can be used₂Pc), copper phthalocyanine (abbreviation: CuPc), and the like; aromatic amine compounds such as 4,4' -bis [ N- (4-diphenylaminophenyl) -N-phenylamino]Biphenyl (DPAB), N' -bis {4- [ bis (3-methylphenyl) amino group]Phenyl } -N, N ' -diphenyl- (1,1' -biphenyl) -4,4' -diamine (abbreviated as DNTPD), etc.; or high molecular weight polymers such as poly (3, 4-ethylenedioxythiophene)/poly (styrenesulfonic acid) (abbreviated as PEDOT/PSS).

As the material having a high hole-injecting property, a composite material including a hole-transporting material and an acceptor material (electron acceptor material) may be used. In this case, electrons are extracted from the hole-transporting material by the acceptor material, holes are generated in the hole-injecting layers (111, 111a, 111b), and the holes are injected into the light-emitting layers (113, 113a, 113b) through the hole-transporting layers (112, 112a, 112 b). The hole injection layers (111, 111a, and 111b) may be formed of a single layer of a composite material including a hole-transporting material and an acceptor material (electron acceptor material), or may be formed of a stack of layers formed using a hole-transporting material and an acceptor material (electron acceptor material).

The hole transport layers (112, 112a, 112b) are layers that transport holes injected from the first electrode 101 or the charge generation layer (104) through the hole injection layers (111, 111a, 111b) into the light-emitting layers (113, 113a, 113 b). The hole-transporting layer (112, 112a, 112b) is a layer containing a hole-transporting material. As the hole-transporting material used for the hole-transporting layers (112, 112a, 112b), a material having the HOMO energy level that is the same as or close to the HOMO energy level of the hole-injecting layers (111, 111a, 111b) is particularly preferably used.

As an acceptor material for the hole injection layer (111, 111a, 111b), an oxide of a metal belonging to any of groups 4 to 8 in the periodic table of elements can be used. Specific examples thereof include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among them, molybdenum oxide is particularly preferably used because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle. Further, examples of the organic acceptor include quinodimethane derivatives, tetrachlorobenzoquinone derivatives, and hexaazatriphenylene derivatives. Specifically, 7,8, 8-tetracyano-2, 3,5, 6-tetrafluoroquinodimethane (abbreviated as F) can be used₄TCNQ), chloranil, 2,3, 6, 7, 10, 11-hexacyan-1, 4, 5,8, 9, 12-hexaazatriphenylene (abbreviation: HAT-CN), and the like. In particular, a compound in which a condensed aromatic ring having a plurality of hetero atoms such as HAT-CN is bonded to an electron-withdrawing group is preferable because it is thermally stable. Further, [ 3] comprising an electron-withdrawing group (particularly, a halogen group such as a fluoro group, a cyano group)]The axially olefin derivative is preferable because it has a very high electron-accepting property, and specific examples thereof include α ', α' -1, 2, 3-cyclopropane triylidenetris [ 4-cyano-2, 3,5, 6-tetrafluorophenylacetonitrile]α ', α' -1, 2, 3-cyclopropane triylidenetris [2, 6-dichloro-3, 5-difluoro-4- (trifluoromethyl) benzeneacetonitrile]α ', α' -1, 2, 3-cyclopropane triylidene tris [2, 3,4, 5, 6-pentafluoro- ]Benzyl cyanide]And the like.

The hole-transporting material used for the hole-injecting layers (111, 111a, 111b) and the hole-transporting layers (112, 112a, 112b) preferably has a hole-transporting property of 10^-6cm²A substance having a hole mobility of greater than/Vs. In addition, any substance other than the above may be used as long as it has a hole-transporting property higher than an electron-transporting property.

As hole-transporting materials, compounds having a pi-electron-rich heteroaromatic compound (e.g., carbazole derivative or indole derivative) or aromatic amine compound, specifically, compounds having a phenyl-carbazole skeleton such as 4,4' -bis [ N- (1-naphthyl) -N-phenylamino ] biphenyl (abbreviated as NPB or α -NPD), N ' -bis (3-methylphenyl) -N, N ' -diphenyl- [1, 1' -biphenyl ] -4,4' -diamine (abbreviated as TPD), 4' -bis [ N- (spiro-9, 9' -bifluoren-2-yl) -N-phenylamino ] biphenyl (abbreviated as BSPB), 4-phenyl-4 ' - (9-phenylfluorene-9-yl) triphenylamine (abbreviated as BPAFLP), 4-phenyl-3 ' - (9-phenylfluorene-9-yl) triphenylamine (abbreviated as BPAFLP), 4-phenyl-4 ' - (9-phenylfluorene-9-carbazol) triphenylamine (abbreviated as 3-phenyl-carbazole), 3- [ N- (3-phenyl) -4' - (9-phenyl) carbazole (abbreviated as DBH-9-phenyl) carbazole), 3-phenyl-4- (3-phenylcarbazole (abbreviated as DBH-phenyl) -N- (3-phenyl) carbazole), 3-phenyl-4- (3-phenylcarbazole (abbreviated as DBH-phenyl-4-phenyl) carbazole), 3-phenyl-4- (3-phenyl-phenylcarbazole), compounds having a skeleton such as DBH-phenyl-4-phenyl-carbazole (abbreviated as DBH-phenyl-4-phenyl-4-phenyl-4-carbazole), 3-phenyl-4-phenyl-4-carbazole (abbreviated as DB9-4-phenyl-4-carbazole), 3-phenyl-4-phenyl-4-phenyl-carbazole (abbreviated as DB9-phenyl-4-phenyl-4-phenyl-4-phenyl-carbazole (abbreviated as DB9-phenyl-4-phenyl-4-phenyl-4-carbazole), 3-phenyl-4-phenyl-carbazole (abbreviated as DB9-phenyl-9-4-phenyl-9-phenyl-carbazole (abbreviated as DB9-phenyl-4-phenyl-9-4-phenyl-9-phenyl-4-phenyl-9-phenyl-9-phenyl-4-phenyl-9-4-phenyl-9-phenyl-9-phenyl-9-phenyl-.

Further, polymer compounds such as Poly (N-vinylcarbazole) (abbreviated as PVK), Poly (4-vinyltriphenylamine) (abbreviated as PVTPA), Poly [ N- (4- { N '- [4- (4-diphenylamino) phenyl ] phenyl-N' -phenylamino } phenyl) methacrylamide ] (abbreviated as PTPDMA), Poly [ N, N '-bis (4-butylphenyl) -N, N' -bis (phenyl) benzidine ] (abbreviated as Poly-TPD) and the like can be used.

Note that the hole-transporting material is not limited to the above-described materials, and one or more of various known materials may be used in combination for the hole injection layers (111, 111a, 111b) and the hole-transporting layers (112, 112a, 112b) as the hole-transporting material. The hole transport layers (112, 112a, 112b) may be formed of a plurality of layers. That is, for example, the first hole transport layer and the second hole transport layer may be stacked.

Next, in the light-emitting element shown in fig. 1D, the light-emitting layer 113a is formed on the hole transport layer 112a in the EL layer 103a by a vacuum evaporation method. After the EL layer 103a and the charge generation layer 104 are formed, the light-emitting layer 113b is formed on the hole transport layer 112b in the EL layer 103b by a vacuum evaporation method.

< light-emitting layer >

The light-emitting layers (113, 113a, 113b, 113c) are layers containing a light-emitting substance. As the light-emitting substance, a substance exhibiting a light-emitting color such as blue, violet, bluish-violet, green, yellowish green, yellow, orange, or red is suitably used. Further, by using different light-emitting substances in each of the plurality of light-emitting layers (113a, 113b, and 113c), different emission colors can be obtained (for example, white emission can be obtained by combining emission colors in a complementary color relationship). Further, a stacked structure in which one light-emitting layer has different light-emitting substances may be employed.

In addition, the light-emitting layers (113, 113a, 113b, and 113c) may each contain one or more kinds of organic compounds (host materials and auxiliary materials) in addition to the light-emitting substance (guest material). In addition, as the one or more kinds of organic compounds, one or both of the hole-transporting material and the electron-transporting material described in this embodiment can be used.

As the light-emitting substance other than the above which can be used for the light-emitting layers (113, 113a, 113b, and 113c), a light-emitting substance which converts singlet excitation energy into light in a visible light region or a light-emitting substance which converts triplet excitation energy into light in the visible light region can be used.

Examples of the other luminescent materials include the following.

Examples of the light-emitting substance which converts a single excitation energy into light emission include substances which emit fluorescence (fluorescent materials), and examples thereof include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives. In particular, the pyrene derivative is preferable because the luminescence quantum yield is high. Specific examples of the pyrene derivative include N, N ' -bis (3-methylphenyl) -N, N ' -bis [3- (9-phenyl-9H-fluoren-9-yl) phenyl ] pyrene-1, 6-diamine (abbreviated as 1,6mMemFLPAPRn), N ' -diphenyl-N, N ' -bis [4- (9-phenyl-9H-fluoren-9-yl) phenyl ] pyrene-1, 6-diamine (abbreviated as 1,6FLPAPRn), N ' -bis (dibenzofuran-2-yl) -N, N ' -diphenylpyrene-1, 6-diamine (abbreviated as 1,6FrAPrn), N ' -bis (dibenzothiophene-2-yl) -N, n '-Diphenylpyrene-1, 6-diamine (abbreviated as 1,6ThAPrn), N' - (pyrene-1, 6-diyl) bis [ (N-phenylbenzo [ b ] naphtho [1,2-d ] furan) -6-amine ] (abbreviated as 1,6BnfAPrn), N '- (pyrene-1, 6-diyl) bis [ (N-phenylbenzo [ b ] naphtho [1,2-d ] furan) -8-amine ] (abbreviated as 1,6BnfAPrn-02), N' - (pyrene-1, 6-diyl) bis [ (6, N-diphenylbenzo [ b ] naphtho [1,2-d ] furan) -8-amine ] (abbreviated as 1,6BnfAPrn-03), and the like.

In addition to the above, 5, 6-bis [4- (10-phenyl-9-anthracenyl) phenyl ] -2, 2 '-bipyridine (abbreviated as PAP2BPy), 5, 6-bis [4' - (10-phenyl-9-anthracenyl) biphenyl-4-yl ] -2, 2 '-bipyridine (abbreviated as PAPP2BPy), N' -bis [4- (9H-carbazol-9-yl) phenyl ] -N, N '-diphenylstilbene-4, 4' -diamine (abbreviated as YGA2S), 4- (9H-carbazol-9-yl) -4'- (10-phenyl-9-anthracenyl) triphenylamine (abbreviated as YGAPA), 4- (9H-carbazol-9-yl) -4' - (9, 10-diphenyl-2-anthryl) triphenylamine (abbreviation: 2YGAPPA), N, 9-diphenyl-N- [4- (10-phenyl-9-anthracenyl) phenyl ] -9H-carbazol-3-amine (abbreviation: PCAPA), 4- (10-phenyl-9-anthracenyl) -4' - (9-phenyl-9H-carbazol-3-yl) triphenylamine (abbreviation: PCBAPA), 4- [4- (10-phenyl-9-anthracenyl) phenyl ] -4' - (9-phenyl-9H-carbazol-3-yl) triphenylamine (abbreviation: pcbappaba), perylene, 2,5,8, 11-tetra- (tert-butyl) perylene (abbreviation: TBP), N ″ - (2-tert-butylanthracene-9, 10-diylbis-4, 1-phenylene) bis [ N, N' -triphenyl-1, 4-phenylenediamine ] (abbreviation: DPABPA), N, 9-diphenyl-N- [4- (9, 10-diphenyl-2-anthracenyl) phenyl ] -9H-carbazol-3-amine (abbreviation: 2PCAPPA), N- [4- (9, 10-diphenyl-2-anthryl) phenyl ] -N, N' -triphenyl-1, 4-phenylenediamine (abbreviation: 2DPAPPA), and the like.

Examples of the light-emitting substance which converts triplet excitation energy into light emission include a substance which emits phosphorescence (phosphorescent material) and a Thermally Activated Delayed Fluorescence (TADF) material which exhibits thermally activated delayed fluorescence.

Examples of the phosphorescent material include an organometallic complex, a metal complex (platinum complex), a rare earth metal complex, and the like. Such a substance exhibits a different emission color (emission peak) for each substance, and is therefore appropriately selected and used as needed.

The following can be mentioned as examples of phosphorescent materials which exhibit blue or green color and have an emission spectrum with a peak wavelength of 450nm to 570 nm.

For example, tris {2- [5- (2-methylphenyl) -4- (2, 6-dimethylphenyl) -4H-1, 2, 4-triazol-3-yl-. kappa.N²]Phenyl-kappa C iridium (III) (abbreviation: [ Ir (mpptz-dmp) ]₃]) Tris (5-methyl-3, 4-diphenyl-4H-1, 2, 4-triazole) iridium (III) (abbreviation: [ Ir (Mptz)₃]) Tris [4- (3-biphenyl) -5-isopropyl-3-phenyl-4H-1, 2, 4-triazole]Iridium (III) (abbreviation: [ Ir (iPrptz-3b)₃]) Tris [3- (5-biphenyl) -5-isopropyl-4-phenyl-4H-1, 2, 4-triazole]Iridium (III) (abbreviation: [ Ir (iPr5btz)₃]) And organometallic complexes having a 4H-triazole skeleton; tris [ 3-methyl-1- (2-methylphenyl) -5-phenyl-1H-1, 2, 4-triazole]Iridium (III) (abbreviation: [ Ir (Mptz1-mp)₃]) Tris (1-methyl-5-phenyl-3-propyl-1H-1, 2, 4-triazole) iridium (III) (abbreviation: [ Ir (Prptz1-Me)₃]) And the like organometallic complexes having a 1H-triazole skeleton; fac-tris [1- (2, 6-diisopropylphenyl) -2-phenyl-1H-imidazole]Iridium (III) (abbreviation: [ Ir (iPrpmi)₃]) Tris [3- (2, 6-dimethylphenyl) -7-methylimidazo [1, 2-f ]]Phenanthridine radical]Iridium (III) (abbreviation: [ Ir (dmpimpt-Me)₃]) And the like organic metal complexes having an imidazole skeleton; and bis [2- (4', 6' -difluorophenyl) pyridinato-N, C²']Iridium (III) tetrakis (1-pyrazolyl) borate (FIr 6 for short), bis [2- (4', 6' -difluorophenyl) pyridinato-N, C²']Iridium (III) picolinate (FIrpic), bis {2- [3', 5' -bis (trifluoromethyl) phenyl]pyridinato-N, C²' } Iridium (III) picolinate (abbreviation: [ Ir (CF)₃ppy)₂(pic)]) Bis [2- (4', 6' -difluorophenyl) pyridinato-N, C²']Organometallic complexes in which an electron-withdrawing group-containing phenylpyridine derivative is a ligand, such as iridium (III) acetylacetonate (FIr (acac)).

The phosphorescent material exhibiting green or yellow color and having an emission spectrum with a peak wavelength of 495nm or more and 590nm or less includes the following materials.

For example, tris (4)-methyl-6-phenylpyrimidine) iridium (III) (abbreviation: [ Ir (mppm)₃]) Tris (4-tert-butyl-6-phenylpyrimidine) iridium (III) (abbreviation: [ Ir (tBuppm)₃]) And (acetylacetonate) bis (6-methyl-4-phenylpyrimidine) iridium (III) (abbreviation: [ Ir (mppm)₂(acac)]) And (acetylacetonate) bis (6-tert-butyl-4-phenylpyrimidine) iridium (III) (abbreviation: [ Ir (tBuppm)₂(acac)]) (Acetylacetonate) bis [6- (2-norbornyl) -4-phenylpyrimidine]Iridium (III) (abbreviation: [ Ir (nbppm)₂(acac)]) (Acetylacetonate) bis [ 5-methyl-6- (2-methylphenyl) -4-phenylpyrimidine]Iridium (III) (abbreviation: [ Ir (mpmppm))₂(acac)]) And (acetylacetonate) bis {4, 6-dimethyl-2- [6- (2, 6-dimethylphenyl) -4-pyrimidinyl-. kappa.N³]Phenyl-. kappa.C } Iridium (III) (abbreviation: [ Ir (dmppm-dmp) ]₂(acac)]) And (acetylacetonate) bis (4, 6-diphenylpyrimidine) iridium (III) (abbreviation: [ Ir (dppm)₂(acac)]) And the like organometallic iridium complexes having a pyrimidine skeleton; (Acetylacetonato) bis (3, 5-dimethyl-2-phenylpyrazine) Iridium (III) (abbreviation: [ Ir (mppr-Me)₂(acac)]) And (acetylacetonate) bis (5-isopropyl-3-methyl-2-phenylpyrazine) iridium (III) (abbreviation: [ Ir (mppr-iPr)₂(acac)]) And the like organometallic iridium complexes having a pyrazine skeleton; tris (2-phenylpyridinato-N, C)²') Iridium (III) (abbreviation: [ Ir (ppy)₃]) Bis (2-phenylpyridinato-N, C)²') Iridium (III) acetylacetone (abbreviation: [ Ir (ppy)₂(acac)]) Bis (benzo [ h ]]Quinoline) iridium (III) acetylacetone (abbreviation: [ Ir (bzq)₂(acac)]) Tris (benzo [ h ]) or a salt thereof]Quinoline) iridium (III) (abbreviation: [ Ir (bzq)₃]) Tris (2-phenylquinoline-N, C)^2′) Iridium (III) (abbreviation: [ Ir (pq)₃]) Bis (2-phenylquinoline-N, C)²') Iridium (III) acetylacetone (abbreviation: [ Ir (pq)₂(acac)]) [2- (4-phenyl-2-pyridyl-. kappa.N) phenyl-. kappa.C]Bis [2- (2-pyridyl-. kappa.N) phenyl-. kappa.C]Iridium (III) (abbreviation: [ Ir (ppy)₂(4dppy)]) Bis [2- (2-pyridyl-. kappa.N) phenyl-. kappa.C][2- (4-methyl-5-phenyl-2-pyridyl-. kappa.N) phenyl-. kappa.C]And the like organometallic iridium complexes having a pyridine skeleton; bis (2, 4-diphenyl-1, 3-oxazole-N, C²') Iridium (III) acetylacetone (abbreviation: [ Ir (dpo)₂(acac)]) Bis {2- [4' - (perfluorophenyl) phenyl]pyridine-N, C²' } Iridium (III) acetylacetone (abbreviation: [ Ir (p-PF-ph)₂(acac)]) Bis (2-phenylbenzothiazole-N, C)²') Iridium (III) acetylacetone (abbreviation: [ Ir (bt)₂(acac)]) And organometallic complexes, tris (acetylacetonate) (monophenanthroline) terbium (III) (abbreviation: [ Tb (acac)₃(Phen)]) And the like.

The following can be mentioned as examples of phosphorescent materials which exhibit yellow or red color and have an emission spectrum with a peak wavelength of 570nm to 750 nm.

For example, (diisobutyrylmethaneato) bis [4, 6-bis (3-methylphenyl) pyrimidino]Iridium (III) (abbreviation: [ Ir (5mdppm)₂(dibm)]) Bis [4, 6-bis (3-methylphenyl) pyrimidino radical](Dipivaloylmethane) Iridium (III) (abbreviation: [ Ir (5 mddppm)₂(dpm)]) Bis [4, 6-di (naphthalen-1-yl) pyrimidinium radical](Dipivaloylmethane) Iridium (III) (abbreviation: [ Ir (d1npm)₂(dpm)]) And the like organic metal complexes having a pyrimidine skeleton; (acetylacetonato) bis (2, 3, 5-triphenylpyrazine) iridium (III) (abbreviation: [ Ir (tppr))₂(acac)]) Bis (2, 3, 5-triphenylpyrazine) (dipivaloylmethane) iridium (III) (abbreviation: [ Ir (tppr)₂(dpm)]) Bis {4, 6-dimethyl-2- [3- (3, 5-dimethylphenyl) -5-phenyl-2-pyrazinyl-. kappa.N]Phenyl-kappa C } (2, 6-dimethyl-3, 5-heptanedione-kappa)²O, O') iridium (III) (abbreviation: [ Ir (dmdppr-P)₂(dibm)]) Bis {4, 6-dimethyl-2- [5- (4-cyano-2, 6-dimethylphenyl) -3- (3, 5-dimethylphenyl) -2-pyrazinyl-. kappa.N]Phenyl- κ C } (2,2, 6, 6-tetramethyl-3, 5-heptanedione- κ)²O, O') iridium (III) (abbreviation: [ Ir (dmdppr-dmCP)₂(dpm)]) (acetylacetone) bis [ 2-methyl-3-phenylquinoxalineato)]-N，C^2’]Iridium (III) (abbreviation: [ Ir (mpq))₂(acac)]) (acetylacetone) bis (2, 3-diphenylquinoxalineato) -N, C^2’]Iridium (III) (abbreviation: [ Ir (dpq))₂(acac)]) (acetylacetonato) bis [2, 3-bis (4-fluorophenyl) quinoxalato)]Iridium (III) (abbreviation: [ Ir (Fdpq)₂(acac)]) And the like organic metal complexes having a pyrazine skeleton; tris (1-phenylisoquinoline-N, C)^2’) Iridium (III) (abbreviation: [ Ir (piq)₃]) Bis (1)-phenylisoquinoline-N, C²') Iridium (III) acetylacetone (abbreviation: [ Ir (piq)₂(acac)]) Bis [4, 6-dimethyl-2- (2-quinolyl-. kappa.N) phenyl-. kappa.C](2, 4-Pentanedionato-. kappa.)²O, O') iridium (III) and the like having a pyridine skeleton; 2,3, 7,8, 12, 13, 17, 18-octaethyl-21H, 23H-porphyrin platinum (II) (abbreviation [ PtOEP ]]) And platinum complexes; and tris (1, 3-diphenyl-1, 3-propanedione (propanoiono)) (monophenanthroline) europium (III) (abbreviation: [ Eu (DBM))₃(Phen)]) Tris [1- (2-thenoyl) -3,3, 3-trifluoroacetone](Monophenanthroline) europium (III) (abbreviation: [ Eu (TTA))₃(Phen)]) And the like.

As the organic compound (host material, assist material) used for the light-emitting layers (113, 113a, 113b, 113c), one or more kinds of substances having a larger energy gap than that of the light-emitting substance (guest material) can be used. When a plurality of organic compounds are used for the light-emitting layers (113, 113a, 113b, and 113c), a compound which forms an exciplex and a light-emitting substance are preferably combined. By adopting the above-described structure, light emission by use of EXTET (excimer-Triplet Energy Transfer) which is Energy Transfer from the Exciplex to the light-emitting substance can be obtained. In this case, any of various organic compounds may be appropriately used in combination, but in order to efficiently form an exciplex, it is particularly preferable to combine a compound that easily accepts holes (hole-transporting material) and a compound that easily accepts electrons (electron-transporting material). The organic compound according to one embodiment of the present invention has a low LUMO level and is suitable for a compound that easily receives electrons.

When the light-emitting substance is a fluorescent material, an organic compound having a large singlet excited state and a small triplet excited state is preferably used as a host material. For example, an anthracene derivative or a tetracene derivative is preferably used. Specifically, 9-phenyl-3- [4- (10-phenyl-9-anthryl) phenyl ] -9H-carbazole (abbreviated as PCzPA), 3- [4- (1-naphthyl) -phenyl ] -9-phenyl-9H-carbazole (abbreviated as PCPN), 9- [4- (10-phenyl-9-anthracene) phenyl ] -9H-carbazole (abbreviated as CzPA), 7- [4- (10-phenyl-9-anthryl) phenyl ] -7H-dibenzo [ c, g ] carbazole (abbreviated as cgDBCzPA), 6- [3- (9, 10-diphenyl-2-anthryl) phenyl ] -benzo [ b ] naphtho [1,2-d ] furan (abbreviated as 2mBnfPPA), 9-phenyl-10- {4- (9-phenyl-9H-fluoren-9-yl) -biphenyl-4' -yl } anthracene (abbreviated as FLPPA), 5, 12-diphenyltetracene, 5, 12-bis (biphenyl-2-yl) tetracene, and the like.

When the light-emitting substance is a phosphorescent material, an organic compound having triplet excitation energy larger than triplet excitation energy (energy difference between a ground state and a triplet excited state) of the light-emitting substance may be selected as a host material. In this case, a zinc or aluminum-based metal complex, an oxadiazole derivative, a triazole derivative, a benzimidazole derivative, a quinoxaline derivative, a dibenzoquinoxaline derivative, a dibenzothiophene derivative, a dibenzofuran derivative, a pyrimidine derivative, a triazine derivative, a pyridine derivative, a bipyridine derivative, a phenanthroline derivative, an aromatic amine, a carbazole derivative, or the like can be used.

More specifically, the following hole-transporting material and electron-transporting material can be used as the host material.

Examples of the host material having a high hole-transporting property include aromatic amine compounds such as N, N ' -di (p-tolyl) -N, N ' -diphenyl-p-phenylenediamine (DTDPPA), 4' -bis [ N- (4-diphenylaminophenyl) -N-phenylamino ] biphenyl (DPAB), N ' -bis {4- [ bis (3-methylphenyl) amino ] phenyl } -N, N ' -diphenyl- (1,1' -biphenyl) -4,4' -diamine (DNTPD), and 1,3, 5-tris [ N- (4-diphenylaminophenyl) -N-phenylamino ] benzene (DPA 3B).

Examples of the carbazole derivative include 3- [ N- (4-diphenylaminophenyl) -N-phenylamino ] -9-phenylcarbazole (abbreviated as PCzDPA1), 3, 6-bis [ N- (4-diphenylaminophenyl) -N-phenylamino ] -9-phenylcarbazole (abbreviated as PCzDPA2), 3, 6-bis [ N- (4-diphenylaminophenyl) -N- (1-naphthyl) amino ] -9-phenylcarbazole (abbreviated as PCzTPN2), 3- [ N- (9-phenylcarbazol-3-yl) -N-phenylamino ] -9-phenylcarbazole (abbreviated as PCzPCA1), 3, 6-bis [ N- (9-phenylcarbazol-3-yl) -N-phenylamino ] -9-phenylcarbazole (abbreviated as: PCzPCA2), 3- [ N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino ] -9-phenylcarbazole (abbreviation: PCzPCN1), and the like. Examples of the carbazole derivative include 4,4' -bis (N-carbazolyl) biphenyl (abbreviated as CBP), 1,3, 5-tris [4- (N-carbazolyl) phenyl ] benzene (abbreviated as TCPB), and 1, 4-bis [4- (N-carbazolyl) phenyl ] -2,3,5, 6-tetraphenylbenzene.

Further, as materials having high hole transport properties, compounds such as 4,4 '-bis [ N- (1-naphthyl) -N-phenylamino ] biphenyl (abbreviated as NPB or α -NPD), N' -bis (3-methylphenyl) -N, N '-diphenyl- [1, 1' -biphenyl ] -4,4 '-diamine (abbreviated as TPD), 4' -tris (carbazol-9-yl) triphenylamine (abbreviated as TCTA), 4 '-tris [ N- (1-naphthyl) -N-phenylamino ] triphenylamine (abbreviated as 1' -TNATA), 4 '-tris (N, N-diphenylamino) triphenylamine (abbreviated as TDATA), 4' -tris [ N- (3-methylphenyl) -N-phenylamino ] triphenylamine (abbreviated as m-MTDATA), 4 '-bis [ N- (spiro-9, 9' -biphenylyl) -2-yl) -N-phenylamino ] biphenyl (abbreviated as 1- (9-phenyl) fluorene), 3-phenyl-naphthyl-4-phenyl-fluorene (abbreviated as 2- (9-phenyl) fluorene), diphenyl-9-phenyl-N-phenyl-carbazole (abbreviated as 2-9-phenyl) fluorene), diphenyl-9-phenyl-7-phenyl-N- (9-phenyl) fluorene (abbreviated as DPH-9-phenyl-9-phenyl-9-phenyl-7-phenyl-7-phenyl-7-phenyl-4-phenyl-7-phenyl-triphenylamine (abbreviated as DPH-phenyl-7-phenyl-7-phenyl-7-phenyl-4-7-phenyl-7-phenyl-7-phenyl-7-phenyl-4-phenyl-7-phenyl-7-phenyl-7-phenyl-7-phenyl-7-4-phenyl-7-phenyl-4-phenyl-7-phenyl-4-phenyl-7-phenyl-7-phenyl-7-phenyl-7-phenyl-five, 4-phenyl-five.

Examples of the host material having a high electron-transporting property include metal complexes having a quinoline skeleton or a benzoquinoline skeleton, such as tris (8-quinolinolato) aluminum (III) (abbreviated as "Alq") and tris (4-methyl-8-quinolinolato) aluminum (III) (abbreviated as "Almq")₃) Bis (10-hydroxybenzo [ h ]]Quinoline) beryllium (II) (abbreviation: BeBq₂) Bis (2-methyl-8-quinolinol) (4-phenylphenol) aluminum (III) (abbreviation: BAlq), bis (8-hydroxyquinoline) zinc (II) (abbreviation: znq), and the like. In addition to this, for example, bis [2- (2-benzoxazolyl) phenol may be used]Zinc (II) (ZnPBO for short), bis [2- (2-benzothiazolyl) phenol]Zinc (II) (simple)Weighing: ZnBTZ), and the like, and metal complexes having oxazole-based ligands and thiazole-based ligands. In addition to the metal complex, 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1, 3, 4-oxadiazole (abbreviated as PBD), 1, 3-bis [5- (p-tert-butylphenyl) -1, 3, 4-oxadiazol-2-yl]Benzene (abbreviated as OXD-7), 9- [4- (5-phenyl-1, 3, 4-oxadiazole-2-yl) phenyl]Oxadiazole derivatives such as-9H-carbazole (abbreviated as CO 11); triazole derivatives such as 3- (4-biphenyl) -4-phenyl-5- (4-tert-butylphenyl) -1, 2, 4-triazole (abbreviated as TAZ); 2, 2' - (1, 3, 5-benzenetriyl) tris (1-phenyl-1H-benzimidazole) (abbreviated to TPBI), 2- [3- (dibenzothiophen-4-yl) phenyl]Compounds having an imidazole skeleton (particularly, benzimidazole derivatives) such as 1-phenyl-1H-benzimidazole (abbreviated as mDBTBIm-II); compounds having an oxazole skeleton (particularly, benzoxazole derivatives) such as 4,4' -bis (5-methylbenzoxazolyl-2-yl) stilbene (abbreviated as BzOs); phenanthroline derivatives such as bathophenanthroline (abbreviated as BPhen), bathocuproine (abbreviated as BCP), 2, 9-bis (naphthalene-2-yl) -4, 7-diphenyl-1, 10-phenanthroline (abbreviated as NBPhen); 2- [3- (dibenzothiophen-4-yl) phenyl]Dibenzo [ f, h ]]Quinoxaline (abbreviation: 2mDBTPDBq-II), 2- [3' - (dibenzothiophen-4-yl) biphenyl-3-yl]Dibenzo [ f, h ]]Quinoxaline (abbreviation: 2mDBTBPDBq-II), 2- [3' - (9H-carbazol-9-yl) biphenyl-3-yl]Dibenzo [ f, h ]]Quinoxaline (abbreviation: 2mCzBPDBq), 2- [4- (3, 6-diphenyl-9H-carbazol-9-yl) phenyl]Dibenzo [ f, h ]]Quinoxaline (abbreviation: 2CzPDBq-III), 7- [3- (dibenzothiophen-4-yl) phenyl]Dibenzo [ f, h ]]Quinoxaline (abbreviation: 7mDBTPDBq-II), 6- [3- (dibenzothiophene-4-yl) phenyl]Dibenzo [ f, h ]]Quinoxaline (abbreviation: 6mDBTPDBq-II), 4, 6-bis [3- (phenanthrene-9-yl) phenyl]Pyrimidine (abbreviation: 4, 6mPnP2Pm), 4, 6-bis [3- (4-dibenzothienyl) phenyl]Pyrimidine (abbreviation: 4, 6mDBTP2Pm-II), 4, 6-bis [3- (9H-carbazol-9-yl) phenyl]Heterocyclic compounds having a diazine skeleton such as pyrimidine (4, 6mCZP2 Pm); 2- {4- [3- (N-phenyl-9H-carbazol-3-yl) -9H-carbazol-9-yl]Heterocyclic compounds having a triazine skeleton such as phenyl } -4, 6-diphenyl-1, 3, 5-triazine (abbreviated as: PCCzPTzn); 3, 5-bis [3- (9H-carbazol-9-yl) phenyl]Pyridine (35 DCzPPy for short), 1,3, 5-tri [3- (3-pyridyl) phenyl]Benzene (Tmpy;)PB), and the like. In addition, polymer compounds such as poly (2, 5-pyridyldiyl) (abbreviated as PPy) and poly [ (9, 9-dihexylfluorene-2, 7-diyl) -co- (pyridine-3, 5-diyl) can also be used](abbreviation: PF-Py), poly [ (9, 9-dioctylfluorene-2, 7-diyl) -co- (2,2 '-bipyridine-6, 6' -diyl)](abbreviated as PF-BPy).

Further, examples of the host material include anthracene derivatives, phenanthrene derivatives, pyrene derivatives, and the like,

Derivative, dibenzo [ g, p ]]

Derivatives, and the like. Specific examples thereof include 9, 10-diphenylanthracene (DPAnth), N-diphenyl-9- [4- (10-phenyl-9-anthryl) phenyl]-9H-carbazole-3-amine (CzA 1-1 PA), 4- (10-phenyl-9-anthryl) triphenylamine (DPhPA), YGAPA, PCAPA, N, 9-diphenyl-N- {4- [4- (10-phenyl-9-anthryl) phenyl]Phenyl } -9H-carbazole-3-amine (PCAPBA), 2PCAPA, 6, 12-dimethoxy-5, 11-diphenyl

DBC1, 9- [4- (10-phenyl-9-anthracene) phenyl]-9H-carbazole (CzPA), 3, 6-diphenyl-9- [4- (10-phenyl-9-anthryl) phenyl]-9H-carbazole (abbreviated as DPCzPA), 9, 10-bis (3, 5-diphenylphenyl) anthracene (abbreviated as DPPA), 9, 10-bis (2-naphthyl) anthracene (abbreviated as DNA), 2-tert-butyl-9, 10-bis (2-naphthyl) anthracene (abbreviated as t-BuDNA), 9' -bianthracene (abbreviated as BANT), 9' - (stilbene-3, 3' -diyl) phenanthrene (abbreviated as DPNS), 9' - (stilbene-4, 4' -diyl) phenanthrene (abbreviated as DPNS2), and 1,3, 5-tris (1-pyrenyl) benzene (abbreviated as TPB 3).

When a plurality of organic compounds are used in the light-emitting layer (113, 113a, 113b, 113c), two compounds (a first compound and a second compound) which form an exciplex and an organometallic complex are preferably used in combination. In this case, various organic compounds can be used in combination as appropriate, but in order to efficiently form an exciplex, it is particularly preferable to combine a compound which easily receives holes (a hole-transporting material) and a compound which easily receives electrons (an electron-transporting material). As specific examples of the hole-transporting material and the electron-transporting material, materials described in this embodiment can be used. Because this structure can realize high efficiency, low-voltage and long-life simultaneously.

The TADF material is a material capable of converting a triplet excited state into a singlet excited state (intersystem crossing) by a small amount of thermal energy and efficiently exhibiting luminescence (fluorescence) from the singlet excited state. The conditions under which TADF can be obtained with high efficiency are as follows: the energy difference between the triplet excitation level and the singlet excitation level is 0eV or more and 0.2eV or less, and preferably 0eV or more and 0.1eV or less. The delayed fluorescence exhibited by the TADF material means luminescence having a spectrum similar to that of general fluorescence but having a very long lifetime. The life is 10^-6Second or more, preferably 10^-3For more than a second.

Examples of the TADF material include fullerene or a derivative thereof, an acridine derivative such as luteolin, and eosin. Further, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), palladium (Pd), or the like can be cited. Examples of the metal-containing porphyrin include protoporphyrin-tin fluoride complex (abbreviated as SnF)₂(ProtoIX)), mesoporphyrin-tin fluoride complex (abbreviation: SnF₂(Meso IX)), hematoporphyrin-tin fluoride complex (abbreviation: SnF₂(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (abbreviation: SnF₂(Copro iii-4 Me)), octaethylporphyrin-tin fluoride complex (abbreviation: SnF₂(OEP)), protoporphyrin-tin fluoride complex (abbreviation: SnF₂(Etio I)) and octaethylporphyrin-platinum chloride complex (abbreviation: PtCl₂OEP), and the like.

In addition to the above, 2- (biphenyl-4-yl) -4, 6-bis (12-phenylindolo [2, 3-a ] carbazol-11-yl) -1, 3, 5-triazine (abbreviation: PIC-TRZ), 2- {4- [3- (N-phenyl-9H-carbazol-3-yl) -9H-carbazol-9-yl ] phenyl } -4, 6-diphenyl-1, 3, 5-triazine (abbreviation: PCCzPTzn), 2- [4- (10H-phenoxazin-10-yl) phenyl ] -4, 6-diphenyl-1, 3, 5-triazine (abbreviation: PXZ-TRZ), 3- [4- (5-phenyl-5, 10-dihydrophenazin-10-yl) phenyl ] -4, 5-diphenyl-1, 2, 4-triazole (abbreviation: PPZ-3TPT), 3- (9, 9-dimethyl-9H-acridin-10-yl) -9H-xanthen-9-one (abbreviation: ACRXTN), bis [4- (9, 9-dimethyl-9, 10-dihydroacridine) phenyl ] sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H, 10 ' H-spiro [ acridine-9, 9' -anthracene ] -10 ' -one (abbreviation: ACRSA), etc., having a pi-electron rich heteroaromatic ring and a pi-electron deficient heteroaromatic ring. In addition, in the case where a pi-electron-rich heteroaromatic ring and a pi-electron-deficient heteroaromatic ring are directly bonded to each other, both donor and acceptor of the pi-electron-rich heteroaromatic ring are strong, and the energy difference between a singlet excited state and a triplet excited state is small, which is particularly preferable.

In addition, in the case of using the TADF material, the TADF material may be used in combination with other organic compounds.

Next, in the light-emitting element shown in fig. 1D, an electron-transporting layer 114a is formed over the light-emitting layer 113a in the EL layer 103a by a vacuum evaporation method. After the EL layer 103a and the charge generation layer 104 are formed, an electron transport layer 114b is formed over the light-emitting layer 113b in the EL layer 103b by a vacuum evaporation method.

< Electron transport layer >

The electron transport layer (114, 114a, 114b) is a layer that transports electrons injected from the second electrode 102 or the charge generation layer (104) through the electron injection layer (115, 115a, 115b) into the light emitting layer (113, 113a, 113 b). The electron transport layers (114, 114a, 114b) are layers containing an electron-transporting material. The electron-transporting material used for the electron-transporting layers (114, 114a, 114b) is preferably a material having a thickness of 1 × 10^-6cm²A substance having an electron mobility of greater than/Vs. In addition, any substance other than the above may be used as long as it has a higher electron-transport property than a hole-transport property.

Examples of the material for electron transport include metal complexes having quinoline ligands, benzoquinoline ligands, oxazole ligands and thiazole ligands, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, pyridine derivatives and bipyridine derivatives. In addition to the above, a pi-electron deficient heteroaromatic compound such as a nitrogen-containing heteroaromatic compound may be used.

Specifically, Alq may be used₃Tris (4-methyl-8-hydroxyquinoline) aluminum (III) (Almq for short)₃) Bis (10-hydroxybenzo [ h ]]Quinoline) beryllium (II) (abbreviation: BeBq₂) BAlq, bis [2- (2-hydroxyphenyl) benzoxazole]Zinc (II) (Zn (BOX))₂) Bis [2- (2-hydroxyphenyl) -benzothiazoles]Zinc (II) (abbreviated as Zn (BTZ))₂) And a metal complex, 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1, 3, 4-oxadiazole (abbreviation: PBD), OXD-7, 3- (4' -tert-butylphenyl) -4-phenyl-5- (4 "-biphenyl) -1, 2, 4-triazole (abbreviation: TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenyl) -1, 2, 4-triazole (abbreviation: p-etaz), bathophenanthroline (abbreviation: BPhen), bathocuproine (abbreviation: BCP), 4' -bis (5-methylbenzoxazol-2-yl) stilbene (abbreviation: BzOs), 2- [3- (dibenzothiophen-4-yl) phenyl]Dibenzo [ f, h ]]Quinoxaline (abbreviation: 2mDBTPDBq-II), 2- [3' - (dibenzothiophen-4-yl) biphenyl-3-yl]Dibenzo [ f, h ]]Quinoxaline (abbreviation: 2mDBTBPDBq-II), 2- [4- (3, 6-diphenyl-9H-carbazol-9-yl) phenyl]Dibenzo [ f, h ]]Quinoxaline (abbreviation: 2CzPDBq-III), 7- [3- (dibenzothiophene-4-yl) phenyl]Dibenzo [ f, h ]]Quinoxaline (abbreviation: 7mDBTPDBq-II) and 6- [3- (dibenzothiophen-4-yl) phenyl]Dibenzo [ f, h ]]Quinoxaline derivatives such as quinoxaline (abbreviated as 6mDBTPDBq-II) or dibenzoquinoxaline derivatives.

In addition, polymer compounds such as poly (2, 5-pyridyldiyl) (abbreviated as PPy), poly [ (9, 9-dihexylfluorene-2, 7-diyl) -co- (pyridine-3, 5-diyl) ] (abbreviated as PF-Py), poly [ (9, 9-dioctylfluorene-2, 7-diyl) -co- (2,2 '-bipyridine-6, 6' -diyl) ] (abbreviated as PF-BPy) can also be used.

The electron transport layers (114, 114a, 114b) may be formed of a single layer or two or more layers containing any of the above substances.

In the light-emitting element shown in fig. 1D, an electron injection layer 115a is formed on the electron transport layer 114a in the EL layer 103a by a vacuum evaporation method. Next, the charge generation layer 104 on the EL layer 103a, the hole injection layer 111b, the hole transport layer 112b, the light emitting layer 113b, and the electron transport layer 114b in the EL layer 103b are formed, and then the electron injection layer 115b is formed by a vacuum evaporation method.

< Electron injection layer >

The electron injection layers (115, 115a, 115b) are layers containing a substance having a high electron injection property. As the electron injection layers (115, 115a, 115b), lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF) can be used₂) And lithium oxide (LiO)_x) And the like, alkali metals, alkaline earth metals, or compounds of these metals. In addition, erbium fluoride (ErF) may be used₃) And the like. In addition, an electron salt may be used for the electron injection layer (115, 115a, 115 b). Examples of the electron salt include a mixed oxide of calcium and aluminum to which electrons are added at a high concentration. Further, the electron transport layers (114, 114a, 114b) described above may be used.

Further, a composite material in which an organic compound and an electron donor (donor) are mixed may be used for the electron injection layers (115, 115a, 115 b). This composite material has excellent electron injection and electron transport properties because electrons are generated in an organic compound by an electron donor. In this case, the organic compound is preferably a material excellent in transporting generated electrons, and specifically, for example, an electron transporting material (metal complex, heteroaromatic compound, or the like) used for the electron transporting layers (114, 114a, 114b) as described above can be used. The electron donor may be any one that can supply electrons to the organic compound. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferably used, and examples thereof include lithium, cesium, magnesium, calcium, erbium, and ytterbium. In addition, alkali metal oxides or alkaline earth metal oxides are preferably used, and examples thereof include lithium oxide, calcium oxide, barium oxide, and the like. In addition, lewis bases such as magnesium oxide can also be used. Further, an organic compound such as tetrathiafulvalene (TTF) may be used.

Note that, for example, in the case of amplifying light obtained from the light-emitting layer 113b, it is preferable to form in such a manner that the optical distance between the second electrode 102 and the light-emitting layer 113b is smaller than λ/4 of the wavelength of light exhibited by the light-emitting layer 113 b. In this case, by changing the thickness of the electron transport layer 114b or the electron injection layer 115b, the optical distance can be adjusted.

< Charge generation layer >

The charge generation layer 104 has the following functions: a function of injecting electrons into the EL layer 103a and injecting holes into the EL layer 103b when a voltage is applied to the first electrode 101 (anode) and the second electrode 102 (cathode). The charge generation layer 104 may have a structure in which an electron acceptor (acceptor) is added to a hole-transporting material, or may have a structure in which an electron donor (donor) is added to an electron-transporting material. Alternatively, these two structures may be stacked. Further, by forming the charge generation layer 104 using the above materials, increase in driving voltage at the time of stacking the EL layers can be suppressed.

When the charge generation layer 104 has a structure in which an electron acceptor is added to a hole-transporting material, the material described in this embodiment mode can be used as the hole-transporting material. Further, as the electron acceptor, 7,8, 8-tetracyano-2, 3,5, 6-tetrafluoroquinodimethane (abbreviated as F)₄-TCNQ), chloranil, and the like. In addition, oxides of metals belonging to elements of groups 4 to 8 in the periodic table of elements can be cited. Specific examples thereof include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide.

When the charge generation layer 104 has a structure in which an electron donor is added to an electron-transporting material, the materials described in this embodiment mode can be used as the electron-transporting material. In addition, as the electron donor, alkali metal, alkaline earth metal, rare earth metal, or metal belonging to group 2 or group 13 of the periodic table of the elements, and oxide or carbonate thereof can be used. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide, cesium carbonate, and the like are preferably used. Further, an organic compound such as tetrathionaphthonaphthalene may be used as the electron donor.

Note that the EL layer 103c shown in fig. 1E may have the same structure as the EL layers (103, 103a, 103b) described above. The charge generation layer 104a and the charge generation layer 104b may have the same structure as the charge generation layer 104.

< substrate >

The light-emitting element described in this embodiment mode can be formed over various substrates. There is no particular limitation on the kind of the substrate. Examples of the substrate include a semiconductor substrate (e.g., a single crystal substrate or a silicon substrate), an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate including a stainless steel foil, a tungsten substrate, a substrate including a tungsten foil, a flexible substrate, a bonding film, a paper film including a fibrous material, a base film, and the like.

Examples of the glass substrate include a barium borosilicate glass substrate, an aluminoborosilicate glass substrate, and a soda lime glass substrate. Examples of the flexible substrate, the adhesive film, and the base film include plastics typified by polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyether sulfone (PES), synthetic resins such as polypropylene resins, polypropylene, polyester, polyvinyl fluoride, polyvinyl chloride, polyamide, polyimide, aramid, epoxy, inorganic vapor deposition films, and papers.

In addition, when the light-emitting element described in this embodiment mode is manufactured, a vacuum process such as a vapor deposition method or a solution process such as a spin coating method or an ink jet method can be used. As the vapor deposition method, a physical vapor deposition method (PVD method) such as a sputtering method, an ion plating method, an ion beam vapor deposition method, a molecular beam vapor deposition method, or a vacuum vapor deposition method, a chemical vapor deposition method (CVD method), or the like can be used. In particular, the functional layer (the hole injection layer (111, 111a, 111b), the hole transport layer (112, 112a, 112b), the light emitting layer (113, 113a, 113b, 113c), the electron transport layer (114, 114a, 114b), the electron injection layer (115, 115a, 115b)) and the charge generation layer (104, 104a, 104b) included in the EL layer of the light emitting element can be formed by a method such as a vapor deposition method (vacuum vapor deposition method), a coating method (dip coating method, dye coating method, bar coating method, spin coating method, spray coating method), a printing method (inkjet method, screen printing (stencil printing) method, offset printing (lithography) method, flexography (relief printing) method, gravure printing method, microcontact printing method), or the like.

The materials of the functional layers (the hole injection layers (111, 111a, 111b), the hole transport layers (112, 112a, 112b), the light emitting layers (113, 113a, 113b, 113c), the electron transport layers (114, 114a, 114b), the electron injection layers (115, 115a, 115b)) and the charge generation layers (104, 104a, 104 b)) constituting the EL layers (103, 103a, 103b) of the light emitting element shown in this embodiment mode are not limited to these, and other materials may be used in combination as long as the functions of the respective layers can be achieved. As an example, a high molecular compound (oligomer, dendrimer, polymer, etc.), a medium molecular compound (compound between low and high molecules: molecular weight 400 to 4000), an inorganic compound (quantum dot material, etc.), or the like can be used. As the quantum dot material, a colloidal quantum dot material, an alloy type quantum dot material, a core-shell type quantum dot material, a core type quantum dot material, or the like can be used.

The structure described in this embodiment can be combined with any of the structures described in the other embodiments as appropriate.

(embodiment mode 3)

In this embodiment, a light-emitting device according to an embodiment of the present invention will be described. The light-emitting device shown in fig. 2A is an active matrix light-emitting device in which a transistor (FET)202 and light-emitting elements (203R, 203G, 203B, and 203W) formed over a first substrate 201 are electrically connected, and an EL layer 204 is shared by a plurality of light-emitting elements (203R, 203G, 203B, and 203W), and a microcavity structure in which an optical distance between electrodes of each light-emitting element is adjusted according to a light emission color of each light-emitting element is employed. In addition, a top emission type light-emitting device is used in which light obtained from the EL layer 204 is emitted through color filters (206R, 206G, 206B) formed on the second substrate 205.

In the light-emitting device shown in fig. 2A, the first electrode 207 is used as a reflective electrode, and the second electrode 208 is used as a transflective electrode. As an electrode material for forming the first electrode 207 and the second electrode 208, any electrode material can be used as appropriate with reference to other embodiments.

In fig. 2A, for example, when the light-emitting element 203R is a red light-emitting element, the light-emitting element 203G is a green light-emitting element, the light-emitting element 203B is a blue light-emitting element, and the light-emitting element 203W is a white light-emitting element, as shown in fig. 2B, the gap between the first electrode 207 and the second electrode 208 in the light-emitting element 203R is adjusted to be the optical distance 200R, the gap between the first electrode 207 and the second electrode 208 in the light-emitting element 203G is adjusted to be the optical distance 200G, and the gap between the first electrode 207 and the second electrode 208 in the light-emitting element 203B is adjusted to be the optical distance 200B. In addition, as shown in fig. 2B, optical adjustment can be performed by laminating a conductive layer 210R on the first electrode 207 in the light-emitting element 203R and a conductive layer 210G on the first electrode 207 in the light-emitting element 203G.

Color filters (206R, 206G, 206B) are formed over the second substrate 205. The color filter transmits visible light of a specific wavelength region and blocks the visible light of the specific wavelength region. Therefore, as shown in fig. 2A, by providing a color filter 206R which transmits only light in the red wavelength region at a position overlapping with the light-emitting element 203R, red light can be obtained from the light-emitting element 203R. Further, by providing the color filter 206G which transmits only light of the green wavelength region at a position overlapping with the light emitting element 203G, green light can be obtained from the light emitting element 203G. Further, by providing the color filter 206B which transmits only light in the blue wavelength region at a position overlapping with the light emitting element 203B, blue light can be obtained from the light emitting element 203B. However, white light can be obtained from the light-emitting element 203W without providing a color filter. In addition, a black layer (black matrix) 209 may be provided at an end portion of one type of color filter. The color filters (206R, 206G, 206B) or the black layer 209 may be covered with a protective layer made of a transparent material.

Although the light-emitting device of the structure (top emission type) in which light is extracted on the second substrate 205 side is shown in fig. 2A, a light-emitting device of the structure (bottom emission type) in which light is extracted on the first substrate 201 side where the FET202 is formed as shown in fig. 2C may be employed. In the bottom emission type light emitting device, the first electrode 207 is used as a transflective electrode, and the second electrode 208 is used as a reflective electrode. As the first substrate 201, a substrate having at least light-transmitting property is used. As shown in fig. 2C, the color filters (206R ', 206G ', 206B ') may be provided on the first substrate 201 side of the light-emitting elements (203R, 203G, 203B).

In addition, although fig. 2A illustrates a case where the light-emitting element is a red light-emitting element, a green light-emitting element, a blue light-emitting element, or a white light-emitting element, the light-emitting element according to one embodiment of the present invention is not limited to this configuration, and may include a yellow light-emitting element or an orange light-emitting element. As a material for an EL layer (a light-emitting layer, a hole-injecting layer, a hole-transporting layer, an electron-injecting layer, or a charge-generating layer) used for manufacturing these light-emitting elements, it can be used as appropriate with reference to other embodiments. In this case, it is necessary to appropriately select a color filter according to the emission color of the light-emitting element.

With the above configuration, a light-emitting device including light-emitting elements that emit light of a plurality of colors can be obtained.

The structure described in this embodiment can be combined with any of the structures described in the other embodiments as appropriate.

(embodiment mode 4)

In this embodiment, a light-emitting device according to an embodiment of the present invention will be described.

By using the element structure of the light-emitting element according to one embodiment of the present invention, an active matrix light-emitting device or a passive matrix light-emitting device can be manufactured. In addition, an active matrix light-emitting device has a structure in which a light-emitting element and a transistor (FET) are combined. Thus, both the passive matrix light-emitting device and the active matrix light-emitting device are included in one embodiment of the present invention. The light-emitting element described in another embodiment mode can be applied to the light-emitting device described in this embodiment mode.

In this embodiment, an active matrix light-emitting device will be described with reference to fig. 3A and 3B.

Fig. 3A is a plan view of the light emitting device, and fig. 3B is a sectional view cut along a chain line a-a' in fig. 3A. An active matrix light-emitting device includes a pixel portion 302, a driver circuit portion (source line driver circuit) 303, and a driver circuit portion (gate line driver circuit) (304a and 304b) provided over a first substrate 301. The pixel portion 302 and the driver circuit portions (303, 304a, 304b) are sealed between the first substrate 301 and the second substrate 306 with a sealant 305.

A lead wiring 307 is provided over the first substrate 301. The lead wiring 307 is connected to an FPC308 as an external input terminal. The FPC308 is used to transmit signals (for example, video signals, clock signals, start signals, reset signals, or the like) or potentials from the outside to the driver circuit portions (303, 304a, 304 b). In addition, a Printed Wiring Board (PWB) may be mounted on the FPC 308. The light-emitting device may include the FPC and the PWB mounted thereon.

Fig. 3B illustrates a cross-sectional structure of the light emitting device.

The pixel portion 302 is configured by a plurality of pixels each having an FET (switching FET)311, an FET (current control FET)312, and a first electrode 313 electrically connected to the FET 312. The number of FETs provided in each pixel is not particularly limited, and may be appropriately set as necessary.

Further, the FETs 309, 310, 311, and 312 are not particularly limited, and for example, a staggered transistor or an inverted staggered transistor can be applied. In addition, a transistor structure such as a top gate type or a bottom gate type may be employed.

The crystallinity of a semiconductor which can be used for the FETs 309, 310, 311, and 312 is not particularly limited, and either an amorphous semiconductor or a semiconductor having crystallinity (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor in which a part thereof has a crystalline region) can be used. The use of a semiconductor having crystallinity is preferable because deterioration of transistor characteristics can be suppressed.

As the semiconductor, for example, a group 14 element, a compound semiconductor, an oxide semiconductor, an organic semiconductor, or the like can be used. Typically, a semiconductor containing silicon, a semiconductor containing gallium arsenide, an oxide semiconductor containing indium, or the like can be used.

The driver circuit portion 303 includes FETs 309 and 310. The FETs 309 and 310 may be formed of a circuit including transistors of a single polarity (either of N-type and P-type), or may be formed of a CMOS circuit including N-type and P-type transistors. Further, a configuration having a driving circuit outside may be employed.

The end of the first electrode 313 is covered with an insulator 314. As the insulator 314, an organic compound such as a negative photosensitive resin or a positive photosensitive resin (acrylic resin) or an inorganic compound such as silicon oxide, silicon oxynitride, or silicon nitride can be used. The upper or lower end of the insulator 314 preferably has a curved surface with curvature. This makes it possible to provide a film formed on the insulator 314 with good coverage.

An EL layer 315 and a second electrode 316 are stacked over the first electrode 313. The EL layer 315 includes a light-emitting layer, a hole-injecting layer, a hole-transporting layer, an electron-injecting layer, a charge-generating layer, and the like.

As a constituent element of the light-emitting element 317 described in this embodiment, the structure or material described in other embodiments can be applied. Although not shown here, the second electrode 316 is electrically connected to the FPC308 serving as an external input terminal.

Although only one light-emitting element 317 is shown in the cross-sectional view shown in fig. 3B, a plurality of light-emitting elements are arranged in a matrix in the pixel portion 302. By selectively forming light-emitting elements capable of emitting light of three (R, G, B) colors in the pixel portion 302, a light-emitting device capable of full-color display can be formed. In addition to the light-emitting elements capable of obtaining light emission of three colors (R, G, B), for example, light-emitting elements capable of obtaining light emission of colors such as white (W), yellow (Y), magenta (M), and cyan (C) may be formed. For example, by adding a light-emitting element capable of obtaining the above-described plurality of types of light emission to a light-emitting element capable of obtaining light emission of three (R, G, B) colors, effects such as improvement in color purity and reduction in power consumption can be obtained. In addition, a light-emitting device capable of full-color display may be realized by combining with a color filter. Note that, as the color filter, a color filter of red (R), green (G), blue (B), cyan (C), magenta (M), yellow (Y), or the like can be used.

By attaching the second substrate 306 to the first substrate 301 using the sealant 305, the FETs (309, 310, 311, 312) and the light emitting element 317 over the first substrate 301 are located in a space 318 surrounded by the first substrate 301, the second substrate 306, and the sealant 305. The space 318 may be filled with an inert gas (e.g., nitrogen, argon, or the like) or an organic substance (including the sealant 305).

An epoxy-based resin or frit may be used as the sealant 305. As the sealant 305, a material which is as impermeable to moisture and oxygen as possible is preferably used. In addition, the same material as that of the first substrate 301 can be used for the second substrate 306. Thus, various substrates shown in other embodiments can be used. As the substrate, a plastic substrate made of Fiber Reinforced Plastic (FRP), polyvinyl fluoride (PVF), polyester, acrylic resin, or the like can be used in addition to a glass substrate and a quartz substrate. In the case where a frit is used as a sealant, a glass substrate is preferably used for the first substrate 301 and the second substrate 306 in view of adhesiveness.

As described above, an active matrix light-emitting device can be obtained.

In the case of forming an active matrix light-emitting device over a flexible substrate, the FET and the light-emitting element may be formed directly over the flexible substrate, or the FET and the light-emitting element may be formed over another substrate having a release layer, and then the FET and the light-emitting element may be separated from the release layer by applying heat, force, laser irradiation, or the like, and then transferred to the flexible substrate. As the release layer, for example, a laminate of an inorganic film such as a tungsten film and a silicon oxide film, an organic resin film such as polyimide, or the like can be used. In addition to a substrate in which a transistor can be formed, examples of the flexible substrate include a paper substrate, a cellophane substrate, an aramid film substrate, a polyimide film substrate, a cloth substrate (including natural fibers (silk, cotton, hemp), synthetic fibers (nylon, polyurethane, polyester), regenerated fibers (acetate fibers, cuprammonium fibers, rayon, regenerated polyester), and the like), a leather substrate, a rubber substrate, and the like. By using such a substrate, high resistance and heat resistance can be achieved, and weight reduction and thickness reduction can be achieved.

The structure described in this embodiment can be combined with any of the structures described in the other embodiments as appropriate.

(embodiment 5)

In this embodiment, examples of various electronic devices and automobiles manufactured using the light-emitting device according to one embodiment of the present invention or a display device including the light-emitting element according to one embodiment of the present invention will be described.

The electronic apparatus shown in fig. 4A to 4E may include a housing 7000, a display portion 7001, a speaker 7003, an LED lamp 7004, operation keys 7005 (including a power switch or an operation switch), connection terminals 7006, a sensor 7007 (having a function of measuring a force, a displacement, a position, a velocity, an acceleration, an angular velocity, a rotational speed, a distance, light, liquid, magnetism, a temperature, a chemical substance, sound, time, hardness, an electric field, current, voltage, electric power, radiation, a flow rate, humidity, inclination, vibration, odor, or infrared ray), a microphone 7008, and the like.

Fig. 4A shows a mobile computer which may include a switch 7009, an infrared port 7010, and the like, in addition to those described above.

Fig. 4B shows a portable image reproducing apparatus (for example, a DVD reproducing apparatus) provided with a recording medium, which can include the second display portion 7002, the recording medium reading portion 7011, and the like in addition to the above.

Fig. 4C illustrates a goggle-type display which may include the second display portion 7002, the support portion 7012, the headphones 7013, and the like in addition to the above.

Fig. 4D shows a digital camera having a television receiving function, which may include an antenna 7014, a shutter button 7015, an image receiving portion 7016, and the like in addition to the above.

Fig. 4E shows a mobile phone (including a smartphone), and a display portion 7001, a microphone 7019, a speaker 7003, a camera 7020, an external connection portion 7021, operation buttons 7022, and the like may be included in the housing 7000.

Fig. 4F shows a large television device (also referred to as a television or a television receiver), which may include a housing 7000, a display portion 7001, and the like. In addition, here, the housing 7000 is supported by a stand 7018. In addition, the television apparatus can be operated by using a remote controller 7111 or the like which is separately provided. The display portion 7001 may be provided with a touch sensor, and the display portion 7001 may be touched with a finger or the like to be operated. The remote controller 7111 may include a display unit for displaying data output from the remote controller 7111. By operating keys or a touch panel using the remote controller 7111, channels and volume can be operated, and an image displayed on the display unit 7001 can be operated.

The electronic devices shown in fig. 4A to 4F may have various functions. For example, the following functions may be provided: displaying various information (still images, moving images, character images, etc.) on a display unit; a touch panel; displaying a calendar, date or time, etc.; control of processing by using various software (programs); performing wireless communication; connecting to various computer networks by using a wireless communication function; by using a wireless communication function, various data is transmitted or received; and a display unit for displaying the program or data read from the recording medium. Further, an electronic device having a plurality of display units may have the following functions: one display section mainly displays image information and the other display section mainly displays text information; alternatively, images in consideration of parallax are displayed on a plurality of display units, and a stereoscopic image or the like is displayed. Further, the electronic device having the image receiving unit may have the following functions: shooting a static image; shooting a dynamic image; automatically or manually correcting the shot image; storing the photographed image in a recording medium (external or built-in camera); the captured image is displayed on a display unit or the like. Note that the functions that the electronic apparatuses shown in fig. 4A to 4F may have are not limited to the above-described functions, but may have various functions.

Fig. 4G shows a smart watch including a case 7000, a display unit 7001, operation buttons 7022, an operation button 7023, a connection terminal 7024, a band 7025, a band buckle 7026, and the like.

The display portion 7001 mounted in the housing 7000 also serving as a frame portion has a display region having a non-rectangular shape. The display unit 7001 can display an icon 7027 indicating time, other icons 7028, and the like. The display portion 7001 may be a touch panel (input/output device) to which a touch sensor (input device) is attached.

The smart watch shown in fig. 4G may have various functions. For example, the following functions may be provided: displaying various information (still images, moving images, character images, etc.) on a display unit; a touch panel; displaying a calendar, date or time, etc.; control of processing by using various software (programs); performing wireless communication; connecting to various computer networks by using a wireless communication function; by using a wireless communication function, various data is transmitted or received; and a display unit for displaying the program or data read from the recording medium.

The housing 7000 may have a speaker, a sensor (having a function of measuring a force, a displacement, a position, a velocity, an acceleration, an angular velocity, a rotational speed, a distance, light, liquid, magnetism, temperature, a chemical substance, sound, time, hardness, an electric field, current, voltage, electric power, radiation, flow, humidity, inclination, vibration, smell, or infrared ray), a microphone, or the like.

Note that the light-emitting device of one embodiment of the present invention and the display device including the light-emitting element of one embodiment of the present invention can be used for each display portion of the electronic device described in this embodiment, whereby a long-life electronic device can be realized.

As an electronic device to which the light-emitting device is applied, a foldable portable information terminal shown in fig. 5A to 5C can be given. Fig. 5A shows the portable information terminal 9310 in an expanded state. Fig. 5B shows the portable information terminal 9310 in the middle of changing from one state to the other state of the expanded state and the folded state. Fig. 5C shows a portable information terminal 9310 in a folded state. The portable information terminal 9310 has good portability in the folded state and has a large display area seamlessly connected in the unfolded state, so that it has a high display list.

The display portion 9311 is supported by three housings 9315 to which hinge portions 9313 are connected. The display portion 9311 may be a touch panel (input/output device) to which a touch sensor (input device) is attached. Further, the display portion 9311 is bent at a connecting portion of the two housings 9315 using the hinge portion 9313, whereby the portable information terminal 9310 can be reversibly changed from the unfolded state to the folded state. The light-emitting device according to one embodiment of the present invention can be applied to the display portion 9311. In addition, a long-life electronic apparatus can be realized. The display region 9312 in the display portion 9311 is a display region located on the side of the portable information terminal 9310 in a folded state. An information icon, a shortcut of an application or program that is frequently used, or the like can be displayed in the display region 9312, and information can be confirmed or the application can be started smoothly.

Fig. 6A and 6B show an automobile to which the light-emitting device is applied. That is, the light emitting device may be formed integrally with the automobile. Specifically, the present invention can be applied to a lamp 5101 (including a lamp at the rear of a vehicle body) on the outer side of the vehicle shown in fig. 6A, a hub 5102 of a tire, a part or the whole of a door 5103, and the like. The present invention can be applied to a display portion 5104, a steering wheel 5105, a shift lever 5106, a seat 5107, a rear-view mirror 5108, and the like on the vehicle inside shown in fig. 6B. In addition to this, the present invention can also be applied to a part of a glass window.

Through the above steps, an electronic device or an automobile to which the light-emitting device or the display device according to one embodiment of the present invention is applied can be obtained. In this case, a long-life electronic apparatus can be realized. The electronic device or the automobile to which the light-emitting device or the display device according to one embodiment of the present invention can be applied is not limited to the electronic device or the automobile described in the present embodiment, and can be applied to various fields.

Note that the structure shown in this embodiment mode can be combined with any of the structures shown in the other embodiment modes as appropriate.

(embodiment mode 6)

In this embodiment, a structure of an illumination device manufactured by applying a light-emitting device according to one embodiment of the present invention or a part of light-emitting elements thereof will be described with reference to fig. 7A to 7D.

Fig. 7A to 7D show examples of cross-sectional views of the illumination device. Fig. 7A and 7B are bottom emission type lighting devices in which light is extracted on the substrate side, and fig. 7C and 7D are top emission type lighting devices in which light is extracted on the sealing substrate side.

The lighting device 4000 illustrated in fig. 7A includes a light-emitting element 4002 over a substrate 4001. In addition, the lighting device 4000 includes a substrate 4003 having irregularities on the outer side of the substrate 4001. The light-emitting element 4002 includes a first electrode 4004, an EL layer 4005, and a second electrode 4006.

The first electrode 4004 is electrically connected to the electrode 4007, and the second electrode 4006 is electrically connected to the electrode 4008. In addition, an auxiliary wiring 4009 electrically connected to the first electrode 4004 may be provided. Further, an insulating layer 4010 is formed over the auxiliary wiring 4009.

The substrate 4001 and the sealing substrate 4011 are bonded by a sealant 4012. Further, a drying agent 4013 is preferably provided between the sealing substrate 4011 and the light-emitting element 4002. Since the substrate 4003 has irregularities as shown in fig. 7A, the efficiency of extracting light generated in the light-emitting element 4002 can be improved.

As in the illumination apparatus 4100 shown in fig. 7B, a diffusion plate 4015 may be provided outside the substrate 4001 instead of the substrate 4003.

The lighting device 4200 shown in fig. 7C includes light emitting elements 4202 on a substrate 4201. Light-emitting element 4202 includes a first electrode 4204, an EL layer 4205, and a second electrode 4206.

The first electrode 4204 is electrically connected to the electrode 4207, and the second electrode 4206 is electrically connected to the electrode 4208. In addition, an auxiliary wiring 4209 electrically connected to the second electrode 4206 may be provided. In addition, an insulating layer 4210 may be provided under the auxiliary wiring 4209.

The substrate 4201 and the sealing substrate 4211 having the concave and convex are bonded by a sealant 4212. Further, a barrier film 4213 and a planarizing film 4214 may be provided between the sealing substrate 4211 and the light-emitting element 4202. Since the sealing substrate 4211 has irregularities as shown in fig. 7C, the efficiency of extracting light generated in the light-emitting element 4202 can be improved.

As in the lighting device 4300 shown in fig. 7D, a diffusion plate 4215 may be provided on the light emitting element 4202 instead of the sealing substrate 4211.

As described in this embodiment mode, a lighting device having a desired chromaticity can be provided by applying the light-emitting device according to one embodiment of the present invention or a part of the light-emitting element.

The structure described in this embodiment can be combined with any of the structures described in the other embodiments as appropriate.

(embodiment 7)

In this embodiment, an application example of a lighting device manufactured using the light-emitting device according to one embodiment of the present invention or a part of the light-emitting elements thereof will be described with reference to fig. 8.

As an indoor lighting device, a ceiling spot lamp 8001 can be used. As the ceiling spot lamp 8001, there is a direct mount type or an embedded type. Such lighting devices are manufactured from a combination of a light emitting device and a housing or cover. Besides, the lamp can also be applied to lighting devices of ceiling lamps (hung on ceilings by wires).

In addition, the footlight 8002 can irradiate the ground to improve safety under feet. For example, the use in bedrooms, stairways or passageways is effective. In this case, the size or shape of the footlight may be appropriately changed according to the area or structure of the room. The footlight 8002 may be a mounted lighting device formed by combining a light emitting device and a bracket.

The sheet illuminator 8003 is a film illuminator. Since it is used by being attached to a wall, it can save space and can be applied to various uses. In addition, a large area can be easily realized. Alternatively, it may be attached to a wall or housing having a curved surface.

Further, the lighting device 8004 in which light from the light source is controlled only in a desired direction may be used.

By using the light-emitting device according to one embodiment of the present invention or a part of the light-emitting element thereof in a part of indoor furniture other than the above, a lighting device having a function of furniture can be provided.

As described above, various lighting devices to which the light-emitting device is applied can be obtained. In addition, such a lighting device is included in one embodiment of the present invention.

The structure described in this embodiment can be combined with any of the structures described in the other embodiments as appropriate.

[ example 1]

Synthesis example 1

In this synthesis example, a method for synthesizing an organic compound 4- [3- (dibenzothiophen-4-yl) phenyl ] -8- (triphenylen-2-yl) - [1] benzofuro [3,2-d ] pyrimidine (abbreviated as 8Tp-4mDBtPBfpm) according to an embodiment of the present invention represented by the structural formula (100) of embodiment 1 will be described. The structure of 8Tp-4mDBtPBfpm is shown below.

[ chemical formula 27]

< Synthesis of 8Tp-4mDBtPBfpm >

First, 1.5g of 8-chloro-4- [3- (dibenzothiophen-4-yl) phenyl ] - [1] benzofuro [3,2-d ] pyrimidine, 1.5g of 4,4, 5, 5-tetramethyl-2- (triphenylen-2-yl) -1, 3, 2-dioxolane, 2.7g of tripotassium phosphate, 35mL of diglyme, and 0.93g of t-butanol were placed in a three-necked flask, the air in the flask was replaced with nitrogen, 15mg of palladium (II) acetate and 47mg of bis (1-adamantyl) -n-butylphosphine were added, and then the mixture was heated at 130 ℃ for 6 hours under a nitrogen stream. The obtained reaction product was added with water and filtered, and the residue was washed with water, ethanol, and toluene in this order.

Subsequently, the residue was dissolved in boiling toluene and filtered. Then, the solvent of the obtained filtrate was concentrated and recrystallized, whereby 0.52g of the objective pale yellow solid was obtained in a yield of 25%. The following shows the synthesis scheme (a-1).

[ chemical formula 28]

The resulting pale yellow solid, 0.52g, was purified by sublimation using a gradient sublimation method. In sublimation purification, the solid was heated at 360 ℃ under a pressure of 2.3Pa and an argon gas flow rate of 10 mL/min. After purification by sublimation, 0.36g of the objective yellow solid was obtained in a recovery rate of 69%.

The nuclear magnetic resonance spectroscopy of the obtained yellow solid is shown below (¹H-NMR). In addition, FIG. 9 shows¹H-NMR spectrum. From the results, in this example, 8Tp-4mDBtPBfpm, which is an organic compound represented by the structural formula (100), was obtained.

¹H-NMR.δ(TCE-d₂)：7.44-7.49(m，2H)，7.60-7.66(m，6H)，7.76-7.79(t，1H)，7.84-7.87(t，2H)，7.95(d，1H)，7.98(d，1H)，8.15(d，1H)，8.20(d，2H)，8.63-8.67(m，3H)，8.69-8.76(m，4H)，8.93(s，1H)，9.02(s，1H)，9.31(s，1H)。

Further, FIG. 10A shows an absorption spectrum and an emission spectrum of 8Tp-4mDBtPBfpm in a toluene solution. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity.

The absorption spectrum was measured by an ultraviolet-visible spectrophotometer (model V-550 manufactured by Nippon spectral Co., Ltd.). In order to calculate the absorption spectrum of 8Tp-4mDBtPBfpm in the toluene solution, the absorption spectrum of toluene put in a quartz cell was measured, and the absorption spectrum of toluene put in a quartz cell was subtracted from the absorption spectrum of 8Tp-4mDBtPBfpm in the toluene solution put in a quartz cell. In addition, a PL-EL measuring device (manufactured by Hamamatsu photonics corporation, Japan) was used for the measurement of the emission spectrum. In order to obtain an emission spectrum of 8Tp-4mDBtPBfpm in the toluene solution, the emission spectrum of the toluene solution of 8Tp-4mDBtPBfpm put in a quartz dish was measured.

As shown in FIG. 10A, the 8Tp-4mDBtPBfpm toluene solution has absorption peaks at 283nm, 320nm, and 333nm, and has a peak of emission wavelength at 409nm (excitation wavelength: 333 nm).

Then, the absorption spectrum and emission spectrum of the solid thin film of 8Tp-4mDBtPBfpm were measured. Formed on a quartz substrate by vacuum evaporationA solid film. Further, the absorption spectrum of the thin film utilizes the absorbance (-log) obtained from the transmittance and reflectance of the thin film including the substrate₁₀[％T/100-％R]) And (6) calculating. Note that,% T represents transmittance, and% R represents reflectance. The absorption spectrum was measured using an ultraviolet-visible spectrophotometer (U-4100 manufactured by Hitachi high and New technology Co., Ltd., Japan). The emission spectrum was measured using a fluorescence spectrophotometer (FS 920, manufactured by hamamatsu photonics corporation, japan). Fig. 10B shows an absorption spectrum and an emission spectrum of the obtained solid thin film. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity.

As shown in the results of FIG. 10B, the solid thin film of 8Tp-4mDBtPBfpm has absorption peaks at around 245nm, 270nm and 319nm, and has a peak of emission wavelength at around 440nm (excitation wavelength: 330 nm).

Next, the 8Tp-4mDBtPBfpm obtained in this example was analyzed by Liquid Chromatography-Mass Spectrometry (LC/MS).

In the LC/MS analysis, Liquid Chromatography (LC) separation was performed using UltiMate 3000 manufactured by seimer fisher technologies, and Mass Spectrometry (MS) was performed using Q active manufactured by seimer fisher technologies.

In the LC separation, an arbitrary column was used, the column temperature was 40 ℃ and the conditions for the infusion were as follows: the sample was adjusted by selecting an appropriate solvent and dissolving 8Tp-4mDBtPBfpm at an arbitrary concentration in an organic solvent, and the injection amount was 5.0. mu.L.

Using targeted MS²(Targeted-MS²) MS of a component having an ion m/z of 654.18 derived from 8Tp-4mDBtPBfpm²And (6) analyzing. In targeting MS²In the analysis, the mass range of the target ion was set to 654.18 ± 2.0 (isolation window) 4, and detection was performed in the positive mode. The Energy NCE (Normalized Collision Energy) for accelerating the target ions in the Collision cell was set to 70, and the measurement was performed. Fig. 11 shows the resulting MS spectrum.

As can be seen from fig. 11: the daughter ion of 8Tp-4mDBtPBfpm is mainly detected near m/z 626, 591, 471, 451, 394, 369, 341, 315, 286, 271, 260, 226, 197. Since the results of FIG. 11 show features derived from 8Tp-4mDBtPBfpm, it can be said that this is important data for identifying 8Tp-4mDBtPBfpm contained in the mixture.

It is assumed that the daughter ion near m/z 626 is a cation generated by the dissociation of a nitrile due to cleavage of a pyrimidine ring, and the daughter ion near m/z 394 is a cation generated by the dissociation of 4-phenyldibenzothiophene, which indicates that 8Tp-4mDBtPBfpm contains phenyldibenzothiophene.

The ion having m/z around 197 is presumably a cation generated by the desorption of a dibenzothienyl group, which indicates that 8Tp-4mDBtPBfpm contains a dibenzothienyl group.

[ example 2]

Synthesis example 2

In this example, a method for synthesizing 4- [3- (dibenzothiophen-4-yl) phenyl ] -8- (9, 9-dimethylfluoren-2-yl) - [1] benzofuro [3,2-d ] pyrimidine (abbreviated as 8FL-4mDBtPBfpm), which is an organic compound according to an embodiment of the present invention represented by the structural formula (101) of embodiment 1, will be described. The structure of 8FL-4mDBtPBfpm is shown below.

[ chemical formula 29]

< Synthesis of 4- [3- (dibenzothiophen-4-yl) phenyl ] -8- (9, 9-dimethylfluoren-2-yl) - [1] benzofuro [3,2-d ] pyrimidine (abbreviation: 8FL-4mDBtPBfpm) >

First, 1.5g of 8-chloro-4- [3- (dibenzothiophen-4-yl) phenyl ] - [1] benzofuro [3,2-d ] pyrimidine, 1.0g of 9, 9-dimethylfluorene-2-boronic acid, 2.7g of tripotassium phosphate, 35mL of diglyme and 1.9g of t-butanol were placed in a three-necked flask, the air in the flask was replaced with nitrogen, 28mg of palladium (II) acetate and 93mg of bis (1-adamantyl) -n-butylphosphine were added, and then the mixture was heated at 135 ℃ for 15 hours under a nitrogen stream. The obtained reaction product was added with water and filtered, and the residue was washed with water and ethanol in this order.

Subsequently, the residue was dissolved in boiling toluene, and filtered using a filter aid containing celite, alumina, and celite in this order. The obtained solution was concentrated and dried, and recrystallization was performed using toluene and ethanol, whereby 1.6g of an off-white solid of the object was obtained in a yield of 79%. The following shows the synthesis scheme (b-1).

[ chemical formula 30]

1.6g of the obtained off-white solid was purified by sublimation using a gradient sublimation method. In sublimation purification: the solid was heated at 315 ℃ under a pressure of 2.8Pa and an argon gas flow rate of 10 mL/min. After purification by sublimation, 1.0g of a yellow solid of the object was obtained in a recovery rate of 63%.

The nuclear magnetic resonance spectroscopy of the obtained yellow solid is shown below (¹H-NMR). In addition, FIG. 12 shows¹H-NMR spectrum. From the results, in this example, the organic compound 8FL-4mDBtPBfpm represented by the structural formula (101) was obtained.

¹H-NMR.δ(TCE-d₂)：1.50(s，6H)，7.27-7.32(m，2H)，7.40-7.47(m，3H)，7.56-7.63(m，3H)，7.69-7.79(m，5H)，7.82(d，1H)，7.92(d，1H)，8.00(dd，1H)，8.18(dd，2H)，8.55(ds，1H)，8.65(d，1H)，8.96(s，1H)，9.26(s，1H)。

FIG. 13A shows an absorption spectrum and an emission spectrum of 8FL-4mDBtPBfpm in a toluene solution. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity.

The absorption spectrum was measured by an ultraviolet-visible spectrophotometer (model V-550 manufactured by Nippon spectral Co., Ltd.). In order to calculate the absorption spectrum of 8FL-4mDBtPBfpm in the toluene solution, the absorption spectrum of toluene placed in a quartz cell was measured, and the absorption spectrum of toluene placed in a quartz cell was subtracted from the absorption spectrum of 8FL-4mDBtPBfpm in the toluene solution placed in a quartz cell. In addition, a PL-EL measuring device (manufactured by Hamamatsu photonics corporation, Japan) was used for the measurement of the emission spectrum. In order to obtain an emission spectrum of 8FL-4mDBtPBfpm in the toluene solution, the emission spectrum of 8FL-4mDBtPBfpm put in a quartz dish was measured.

As shown in FIG. 13A, the toluene solution of 8FL-4mDBtPBfpm has absorption peaks in the vicinity of 281nm, 294nm, 320nm, and 334nm, and has a peak of the emission wavelength in the vicinity of 422nm (excitation wavelength: 331 nm).

Then, the absorption spectrum and emission spectrum of the solid thin film of 8FL-4mDBtPBfpm were measured. A solid thin film was formed on a quartz substrate by a vacuum evaporation method. Further, the absorption spectrum of the thin film utilizes the absorbance (-log) obtained from the transmittance and reflectance of the thin film including the substrate₁₀[％T/100-％R]) And (6) calculating. Note that,% T represents transmittance, and% R represents reflectance. The absorption spectrum was measured using an ultraviolet-visible spectrophotometer (U-4100 manufactured by Hitachi high and New technology Co., Ltd., Japan). The emission spectrum was measured using a fluorescence spectrophotometer (FS 920, manufactured by hamamatsu photonics corporation, japan). Fig. 13B shows an absorption spectrum and an emission spectrum of the obtained solid thin film. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity.

As shown in the results of FIG. 13B, the solid thin film of 8FL-4mDBtPBfpm had absorption peaks at around 213nm, 237nm, 290nm, 322nm, and 338nm, and had emission wavelength peaks at around 437nm (excitation wavelength: 350 nm).

Next, the 8FL-4mDBtPBfpm obtained in this example was analyzed by Liquid Chromatography-Mass Spectrometry (LC/MS).

In the LC/MS analysis, Liquid Chromatography (LC) separation was performed using UltiMate 3000 manufactured by seimer fisher technologies, and Mass Spectrometry (MS) was performed using Q active manufactured by seimer fisher technologies.

In the LC separation, an arbitrary column was used, the column temperature was 40 ℃ and the conditions for the infusion were as follows: the sample was adjusted by selecting an appropriate solvent and dissolving 8FL-4mDBtPBfpm at an arbitrary concentration in an organic solvent, and the injection amount was 5.0. mu.L.

Using targeted MS²(Targeted-MS²) MS of a component having an ion m/z of 621.19 derived from 8FL-4mDBtPBfpm²And (6) analyzing. In targeting MS²In the analysis, the mass range of the target ion was set to 621.19 ± 2.0 (isolation window) 4, and detection was performed in the positive mode. The Energy NCE (Normalized Collision Energy) for accelerating the target ions in the Collision cell was set to 80, and the measurement was performed. Fig. 14 shows the resulting MS spectrum.

As can be seen from fig. 14: the daughter ion of 8FL-4mDBtPBfpm is mainly detected in the vicinity of m/z 605, 578, 421, 344, 319, 284, 265, 241, and 197. Since the results of FIG. 14 show features derived from 8FL-4mDBtPBfpm, it can be said that this is important data for identifying 8FL-4mDBtPBfpm contained in the mixture.

The ionic ion having m/z in the vicinity of 605 is presumably a cation generated by the elimination of a methyl group in 8FL-4mDBtPBfpm, indicating that 8FL-4mDBtPBfpm contains a methyl group. The other daughter ions were released in the state where the methyl group in 8FL-4mDBtPBfpm was released. The ion near m/z 343 is presumably a cation generated by the elimination of phenyl and dibenzothienyl, and this indicates that 8FL-4mDBtPBfpm includes phenyl and dibenzothienyl.

The ion having m/z around 197 is presumed to be a dibenzothienyl cation, which indicates that 8FL-4mDBtPBfpm contains a dibenzothienyl group.

[ example 3]

Synthesis example 3

In this synthesis example, a method for synthesizing an organic compound 4- [3- (dibenzothiophen-4-yl) phenyl ] -8- (naphthalen-2-yl) - [1] benzofuro [3,2-d ] pyrimidine (abbreviated as 8 β N-4mDBtPBfpm) according to an embodiment of the present invention represented by the structural formula (102) of embodiment 1 will be described, and the structure of 8 β N-4mDBtPBfpm will be shown below.

[ chemical formula 31]

< Synthesis of 4- [3- (dibenzothiophen-4-yl) phenyl ] -8- (naphthalen-2-yl) - [1] benzofuro [3,2-d ] pyrimidine (abbreviation: 8 β N-4mDBtPBfpm) >

First, 8-chloro-4- [3- (dibenzothiophen-4-yl) phenyl]-[1]Benzofuro [3,2-d]1.5g of pyrimidine, 0.73g of 2-naphthylboronic acid, 1.5g of cesium fluoride and 32mL of mesitylene were placed in a 100mL three-necked flask, and the air in the flask was replaced with nitrogen, and 70mg of 2' - (dicyclohexylphosphino) acetophenone diol ketal and tris (dibenzylideneacetone) dipalladium (0) (abbreviated as Pd) were added₂(dba)₃) After 89mg, the mixture was heated at 120 ℃ for 5 hours under a nitrogen stream. The obtained reaction product was added with water and filtered, and the residue was washed with water and ethanol in this order.

This residue was dissolved in toluene, and the mixture was filtered using a filter aid containing celite, alumina, and celite in this order. The solvent of the obtained solution was concentrated and dried, and recrystallization was performed, whereby 1.5g of the objective pale yellow solid was obtained in a yield of 64%. The following shows the synthesis scheme (c-1).

[ chemical formula 32]

1.5g of the obtained pale yellow solid was purified by sublimation using a gradient sublimation method. In the sublimation purification conditions, the solid was heated at 290 ℃ under a pressure of 2.0Pa and an argon gas flow rate of 10 mL/min. After purification by sublimation, 0.60g of the objective yellow solid was obtained in a recovery rate of 39%.

The nuclear magnetic resonance spectroscopy of the obtained yellow solid is shown below (¹H-NMR). In addition, FIG. 15 shows¹From this result, it was found that in this example, the organic compound 8 β N-4mDBtPBfpm represented by the structural formula (102) was obtained.

¹H-NMR.δ(TCE-d₂)：7.45-7.50(m，4H)，7.57-7.62(m，2H)，7.72-7.93(m，8H)，8.03(d，1H)，8.10(s，1H)，8.17(d，2H)，8.60(s，1H)，8.66(d，1H)，8.98(s，1H)，9.28(s，1H)。

Fig. 16A shows an absorption spectrum and an emission spectrum of 8 β N-4mDBtPBfpm in a toluene solution, the horizontal axis represents a wavelength, and the vertical axis represents an absorption intensity and an emission intensity.

The absorption spectrum was measured with an ultraviolet-visible spectrophotometer (model V-550 manufactured by Nippon spectral Co., Ltd.) to calculate the absorption spectrum of 8 β N-4mDBtPBfpm in the toluene solution, the absorption spectrum of toluene put in a quartz cell was measured, and the absorption spectrum of toluene put in a quartz cell was subtracted from the absorption spectrum of toluene solution of 8 β N-4mDBtPBfpm put in a quartz cell.

As shown in FIG. 16A, the 8 β N-4mDBtPBfpm toluene solution has absorption peaks at around 283nm, 290nm, 317nm and 333nm, and has a peak of emission wavelength at around 409nm (excitation wavelength: 337 nm).

Then, the absorption spectrum and emission spectrum of the solid thin film of 8 β N-4mDBtPBfpm were measured, and the solid thin film was formed on a quartz substrate by vacuum deposition, and the absorption spectrum of the thin film was measured by the absorbance (-log) obtained from the transmittance and reflectance of the thin film including the substrate₁₀[％T/100-％R]) And (6) calculating. Note that,% T represents transmittance, and% R represents reflectance. The absorption spectrum was measured using an ultraviolet-visible spectrophotometer (U-4100 manufactured by Hitachi high and New technology Co., Ltd., Japan). The emission spectrum was measured using a fluorescence spectrophotometer (FS 920, manufactured by hamamatsu photonics corporation, japan). Fig. 16B shows an absorption spectrum and an emission spectrum of the obtained solid thin film. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity.

As shown in the results of FIG. 16B, the solid thin film of 8 β N-4mDBtPBfpm had absorption peaks in the vicinity of 243nm, 266nm, 290nm, 314nm and 341nm, and had a peak of emission wavelength in the vicinity of 430nm (excitation wavelength: 330 nm).

Next, the 8 β N-4mDBtPBfpm obtained in this example was analyzed by Liquid Chromatography-Mass Spectrometry (LC/MS).

In the LC/MS analysis, Liquid Chromatography (LC) was performed using UltiMate 3000 manufactured by seimer fisher technologies, and Mass Spectrometry (MS) was performed using Q active manufactured by seimer fisher technologies.

In LC separation, an arbitrary column was used at 40 ℃ and the conditions for infusion were such that a sample was prepared by dissolving an arbitrary concentration of 8 β N-4mDBtPBfpm in an organic solvent with the selection of an appropriate solvent and the injection amount was 5.0. mu.L.

Using targeted MS²(Targeted-MS²) MS of 554.15 m/z component derived from 8 β N-4mDBtPBfpm ion²And (6) analyzing. In targeting MS²In the analysis, the mass range of the target ion was set to 554.15 ± 2.0 (isolation window) 4, and detection was performed in the positive mode. The Energy NCE (Normalized Collision Energy) for accelerating the target ions in the Collision cell was set to 65, and the measurement was performed. Fig. 17 shows the resulting MS spectrum.

Fig. 17 shows that the daughter ions of 8 β N-4mDBtPBfpm are mainly detected in the vicinity of m/z 528, 499, 371, 347, 310, 295, 284, 270, 260, 245, 241, 221, 215, 197, and the results of fig. 17 show features derived from 8 β N-4mDBtPBfpm, and therefore, this is important data for identifying 8 β N-4mDBtPBfpm contained in the mixture.

The ion near 371 m/z is presumably a cation generated by the desorption of a dibenzothienyl group, and this indicates that 8 β N-4mDBtPBfpm contains a dibenzothienyl group.

[ example 4]

In this example, structures, manufacturing methods, and characteristics of light-emitting elements 1 to 3 according to embodiments of the present invention are described, in the light-emitting element 1, 4- [3- (dibenzothiophene-4-yl) phenyl ] -8- (triphenylen-2-yl) - [1] benzofuro [3,2-d ] pyrimidine (abbreviated as 8Tp-4mDBtPBfpm) (structural formula (100)) described in example 1 is used for a light-emitting layer, in the light-emitting element 2, 4- [3- (dibenzothiophene-4-yl) phenyl ] -8- (9, 9-dimethylfluoren-2-yl) - [1] benzofuro [3,2-d ] pyrimidine (abbreviated as 8FL-4mDBtPBfpm) (structural formula (101)) described in example 2 is used for a light-emitting layer, in the light-emitting element 3,4- [3- (dibenzothiophene-4-yl) phenyl ] -8- (naphthalene-2-yl) - [1] benzofuro [3,2-d ] pyrimidine (abbreviated as structural formula (101)) described in example 3 is used for a light-emitting layer, and in the light-emitting element 3, the following specific structural formula (8 β) used in this example is shown in fig. 18.

[ Table 1]

*8Tp-4mDBtPBfpm:PCCP:Ir(ppy)₂(4dppy)(0.6:0.4:0.140nm)

**8FL-4mDBtPBfpm:PCCP:Ir(ppy)₂(4dppy)(0.6:0.4:0.140nm)

***8βN-4mDBtPBfpm:PCCP:Ir(ppy)₂(4dppy)(0.6:0.4:0.140nm)

[ chemical formula 33]

Production of light-emitting element

As shown in fig. 18, in each of the light-emitting elements shown in this embodiment, a hole injection layer 911, a hole transport layer 912, a light-emitting layer 913, an electron transport layer 914, and an electron injection layer 915 are sequentially stacked over a first electrode 901 formed over a substrate 900, and a second electrode 903 is stacked over the electron injection layer 915.

First, a first electrode 901 is formed over a substrate 900. The electrode area was set to 4mm²(2 mm. times.2 mm). In addition, a glass substrate is used as the substrate 900. The first electrode 901 was formed by using indium tin oxide containing silicon oxide (ITSO) with a thickness of 70nm by a sputtering method.

As a pretreatment, the surface of the substrate was washed with water, baked at a temperature of 200 ℃ for 1 hour, and then subjected to UV ozone treatment for 370 seconds.Then, the substrate is transferred to the inside thereof and decompressed to 10^-4In a vacuum deposition apparatus of about Pa, vacuum baking was performed at a temperature of 170 ℃ for 60 minutes in a heating chamber in the vacuum deposition apparatus, and then the substrate was cooled for about 30 minutes.

Next, a hole injection layer 911 is formed on the first electrode 901. Is decompressed to 10 degrees in the vacuum evaporation device^-4After Pa, mixing DBT3P-II and molybdenum oxide at a mass ratio of DBT 3P-II: molybdenum oxide ═ 2: 1 and 50nm thick, to form a hole injection layer 911.

Next, a hole transporting layer 912 is formed on the hole injecting layer 911. The hole transport layer 912 was formed to a thickness of 20nm by depositing pcdbi 1BP by evaporation.

Next, a light-emitting layer 913 is formed over the hole-transporting layer 912.

8Tp-4mDBtPBfpm as a host material, PCCP as an auxiliary material, and [ Ir (ppy) as a guest material (phosphorescent material)₂(4dppy)]The weight ratio of 8Tp-4 mDBtPBfpm: PCCP: [ Ir (ppy)₂(4dppy)]0.6: 0.4: the light-emitting layer 913 of the light-emitting element 1 was formed by co-evaporation as described in 0.1. In addition, the thickness was set to 40 nm.

8FL-4mDBtPBfpm was used as the host material, PCCP was used as the auxiliary material, and [ Ir (ppy) was used as the guest material (phosphorescent material)₂(4dppy)]The weight ratio of 8FL-4 mDBtPBfpm: PCCP: [ Ir (ppy)₂(4dppy)]0.6: 0.4: the light-emitting layer 913 of the light-emitting element 2 was formed by co-evaporation as described in 0.1. In addition, the thickness was set to 40 nm.

8 β N-4mDBtPBfpm was used as a host material, PCCP was used as an auxiliary material, and [ Ir (ppy) was used as a guest material (phosphorescent material)₂(4dppy)]The weight ratio of the N to the N is 8 β N to 4mDBtPBfpm to the PCCP [ Ir (ppy)₂(4dppy)]0.6: 0.4: the light-emitting layer 913 of the light-emitting element 3 was formed by co-evaporation as described in 0.1. In addition, the thickness was set to 40 nm.

Next, an electron transport layer 914 was formed on the light-emitting layer 913, in the light-emitting element 1, the electron transport layer 914 was formed by sequentially performing vapor deposition of 8Tp-4mDBtPBfpm and BPhen to a thickness of 20nm and 15nm, respectively, in the light-emitting element 2, the electron transport layer 914 was formed by sequentially performing vapor deposition of 8FL-4mDBtPBfpm and BPhen to a thickness of 20nm and 15nm, respectively, in the light-emitting element 3, the electron transport layer 914 was formed by sequentially performing vapor deposition of 8 β N-4mDBtPBfpm and BPhen to a thickness of 20nm and 15nm, respectively.

Next, an electron injection layer 915 is formed on the electron transit layer 914. The electron injection layer 915 is formed to have a thickness of 1nm by depositing lithium fluoride (LiF).

Then, a second electrode 903 is formed on the electron injection layer 915. The second electrode 903 is formed to have a thickness of 200nm by an aluminum vapor deposition method. In the present embodiment, the second electrode 903 is used as a cathode.

Through the above steps, light-emitting elements each having an EL layer interposed between a pair of electrodes are formed over the substrate 900. The hole injection layer 911, the hole transport layer 912, the light-emitting layer 913, the electron transport layer 914, and the electron injection layer 915 described above are functional layers that form an EL layer in one embodiment of the present invention. In the vapor deposition process of the above-described manufacturing method, vapor deposition is performed by a resistance heating method.

In addition, another substrate (not shown) was fixed to the substrate 900 with a sealant in a glove box containing a nitrogen atmosphere, and the sealant was applied to the periphery of the light-emitting element formed over the substrate 900 at 6J/cm at the time of sealing²Each of the light-emitting elements manufactured as described above was sealed with another substrate (not shown) by irradiating 365nm ultraviolet light and performing heat treatment at 80 ℃ for 1 hour.

Operating characteristics of light-emitting element

The operating characteristics of each of the fabricated light-emitting elements were measured. The measurement was performed at room temperature (atmosphere maintained at 25 ℃). As a result of the operation characteristics of the light emitting elements 1 to 3, fig. 19 shows a current density-luminance characteristic, fig. 20 shows a voltage-luminance characteristic, fig. 21 shows a luminance-current efficiency characteristic, and fig. 22 shows a voltage-current characteristic.

Further, Table 2 showsGoes out of 1000cd/m²Main initial characteristic values of the respective light emitting elements in the vicinity.

[ Table 2]

From the above results, it is understood that the light-emitting elements manufactured in this example all have good element characteristics.

FIG. 23 shows the signal at 2.5mA/cm²Current density of (a) emission spectrum when a current is applied to each light emitting element. As shown in fig. 23, the emission spectrum of each light-emitting element has a peak around 560nm, and the peak may be derived from [ ir (ppy) ] included in the light-emitting layer 913₂(4dppy)]The light emission of (1).

Next, a reliability test of each light emitting element was performed. Fig. 24 shows the results of the reliability test. In fig. 24, the vertical axis represents the normalized luminance (%) with the initial luminance as 100%, and the horizontal axis represents the driving time (h) of the element. In the reliability test, the light emitting element was driven at a constant current of 2 mA.

As is clear from the results of the reliability tests, each of the light-emitting elements manufactured in this example had good element characteristics.

In addition, each of the light emitting elements shown in this embodiment has the following structure: an exciplex is formed in the light-emitting layer, and energy is transferred from the exciplex to the light-emitting substance [ Ir (ppy) ]₂(4dppy)]In addition, in this structure, 8Tp-4mDBtPBfpm, 8FL-4mDBtPBfpm, and 8 β N-4mDBtPBfpm, which are embodiments of the present invention used in this example, each have a benzofuropyrimidine skeleton, and the LUMO level is deep, and therefore, they are suitable for the formation of an exciplex.

[ example 5]

In this example, the structure, the manufacturing method, and the characteristics of the light-emitting element 4 and the comparative light-emitting element 5 according to one embodiment of the present invention will be described, in the light-emitting element 4, 8 β N-4mDBtPBfpm (structural formula (102)) described in example 3 is used for the light-emitting layer, in the comparative light-emitting element 5, a comparative organic compound 4, 8-bis [3- (dibenzothiophene-4-yl) phenyl ] - [1] benzofuro [3,2-d ] pyrimidine (abbreviated as 4, 8mDBtP2Bfpm) (structural formula (200)) is used for the light-emitting layer, the light-emitting element in this example has the structure shown in fig. 18, table 3 shows a specific structure of the light-emitting element, and chemical formulae of materials used in this example are shown below.

[ Table 3]

*8βN-4mDBtPBfpm:PCCP:Ir(ppy)₂(4dppy)(0.6:0.4:0.140nm)

**4，8mDBtP2Bfpm:PCCP:Ir(ppy)₂(4dppy)(0.6:0.4:0.140nm)

[ chemical formula 34]

Production of light-emitting element

As shown in fig. 18, in each of the light-emitting elements shown in this embodiment, a hole injection layer 911, a hole transport layer 912, a light-emitting layer 913, an electron transport layer 914, and an electron injection layer 915 are sequentially stacked over a first electrode 901 formed over a substrate 900, and a second electrode 903 is stacked over the electron injection layer 915.

First, a first electrode 901 is formed over a substrate 900. The electrode area was set to 4mm²(2 mm. times.2 mm). In addition, a glass substrate is used as the substrate 900. The first electrode 901 was formed by using indium tin oxide containing silicon oxide (ITSO) with a thickness of 70nm by a sputtering method.

As a pretreatment, the surface of the substrate was washed with water, baked at a temperature of 200 ℃ for 1 hour, and then subjected to UV ozone treatment for 370 seconds. Then, the substrate is transferred to the inside thereof and decompressed to 10^-4In a vacuum deposition apparatus of about Pa, and in a heating chamber in the vacuum deposition apparatus, at a temperature of 170 DEG CVacuum baking is performed for 60 minutes, and then the substrate is cooled for about 30 minutes.

Next, a hole injection layer 911 is formed on the first electrode 901. Is decompressed to 10 degrees in the vacuum evaporation device^-4After Pa, mixing DBT3P-II and molybdenum oxide at a mass ratio of DBT 3P-II: molybdenum oxide ═ 2: 1 and 50nm thick, to form a hole injection layer 911.

Next, a hole transporting layer 912 is formed on the hole injecting layer 911. The hole transport layer 912 was formed to a thickness of 20nm by depositing pcdbi 1BP by evaporation.

Next, a light-emitting layer 913 is formed over the hole-transporting layer 912.

8 β N-4mDBtPBfpm was used as a host material, PCCP was used as an auxiliary material, and [ Ir (ppy) was used as a guest material (phosphorescent material)₂(4dppy)]The weight ratio of the N to the N is 8 β N to 4mDBtPBfpm to the PCCP [ Ir (ppy)₂(4dppy)]0.6: 0.4: the light-emitting layer 913 of the light-emitting element 4 was formed by co-evaporation as described in 0.1. In addition, the thickness was set to 40 nm.

4, 8mDBtP2Bfpm was used as a host material, PCCP was used as an auxiliary material, and [ Ir (ppy) was used as a guest material (phosphorescent material)₂(4dppy)]The weight ratio of the components is 4, 8mDBtP2 Bfpm: PCCP: [ Ir (ppy)₂(4dppy)]0.6: 0.4: the light-emitting layer 913 of the comparative light-emitting element 5 was formed by co-evaporation as described in 0.1. In addition, the thickness was set to 40 nm.

Next, an electron transport layer 914 was formed on the light-emitting layer 913, in the light-emitting element 4, the electron transport layer 914 was formed by sequentially performing vapor deposition of 8 β N to 4mDBtPBfpm and BPhen so as to have thicknesses of 20nm and 15nm, respectively, and in the comparative light-emitting element 5, the electron transport layer 914 was formed by sequentially performing vapor deposition of 4, 8mDBtP2Bfpm and BPhen so as to have thicknesses of 20nm and 15nm, respectively.

Next, an electron injection layer 915 is formed on the electron transit layer 914. The electron injection layer 915 is formed to have a thickness of 1nm by depositing lithium fluoride (LiF).

Then, a second electrode 903 is formed on the electron injection layer 915. The second electrode 903 is formed to have a thickness of 200nm by an aluminum vapor deposition method. In the present embodiment, the second electrode 903 is used as a cathode.

Through the above steps, light-emitting elements each having an EL layer interposed between a pair of electrodes are formed over the substrate 900. The hole injection layer 911, the hole transport layer 912, the light-emitting layer 913, the electron transport layer 914, and the electron injection layer 915, which are described in the above steps, are functional layers that form an EL layer in one embodiment of the present invention. In the vapor deposition process of the above-described manufacturing method, vapor deposition is performed by a resistance heating method.

Each of the light-emitting elements formed as described above is sealed with another substrate (not shown) by the following method. In a glove box containing a nitrogen atmosphere, a sealant was applied to the periphery of the light-emitting element formed over the substrate 900, and another substrate (not shown) provided with a desiccant was placed over a desired position of the substrate 900 at 6J/cm²Irradiating 365nm ultraviolet light.

Operating characteristics of light-emitting element

The operating characteristics of the manufactured light-emitting element 4 and the comparative light-emitting element 5 were measured. The measurement was performed at room temperature (atmosphere maintained at 25 ℃). As a result of the operation characteristics of the light-emitting element 4 and the comparative light-emitting element 5, fig. 25 shows the current density-luminance characteristic, fig. 26 shows the voltage-luminance characteristic, fig. 27 shows the luminance-current efficiency characteristic, and fig. 28 shows the voltage-current characteristic.

Furthermore, Table 4 shows 1000cd/m²The main initial characteristic values of the neighboring light-emitting elements 4 and the comparative light-emitting element 5.

[ Table 4]

From the above results, it is understood that the light-emitting element 4 manufactured in this example has good element characteristics.

FIG. 29 shows the signal at 2.5mA/cm²Current density of (2) emission spectra when a current was applied to the light-emitting element 4 and the light-emitting element 5 were compared. As shown in FIG. 29, the emission spectrum of each light-emitting element was 560nmThe light-emitting layer 913 may contain ir (ppy) as a source of the peak₂(4dppy)]The light emission of (1).

Next, reliability tests of the light-emitting element 4 and the comparative light-emitting element 5 were performed. Fig. 30 shows the results of the reliability test. In fig. 30, the vertical axis represents the normalized luminance (%) with the initial luminance as 100%, and the horizontal axis represents the driving time (h) of the element. In the reliability test, the light emitting element was driven at a constant current of 2 mA.

As is clear from the results of the reliability test, the reliability of the light-emitting element 4 according to one embodiment of the present invention is higher than that of the comparative light-emitting element 5, specifically, when the comparative luminance reaches the decay time (LT90) of 90% of the initial luminance, LT90 of the light-emitting element 4 is 215 hours, and LT90 of the comparative light-emitting element 5 is 78 hours, which means that the lifetime of the light-emitting element 4 is about 2.8 times that of the comparative light-emitting element 5.

[ example 6]

Synthesis example 4

In this synthesis example, a method for synthesizing an organic compound 8- (dibenzothiophen-4-yl) -2- [3- (dibenzothiophen-4-yl) phenyl ] - [1] benzofuro [3,2-d ] pyrimidine (abbreviated as 8DBt-2mDBtPBfpm) according to an embodiment of the present invention represented by the structural formula (145) of embodiment 1 will be described. The structures of 8DBt-2mDBtPBfpm are shown below.

[ chemical formula 35]

< step 1: synthesis of 2-chloro-4- (dibenzothiophen-4-yl) phenol >

First, 3.4g of 4-dibenzothiopheneboronic acid and tris (2-methylphenyl) phosphine (abbreviation: P (o-tolyl)₃)0.18g, carbon4.1g of potassium salt, 56mL of toluene, 19mL of ethanol, and 15mL of water were placed in a three-necked flask, and the flask was degassed by stirring under reduced pressure, and then the air in the flask was replaced with nitrogen. To the mixture were added 3.1g of 4-bromo-2-chlorophenol and palladium (II) acetate (abbreviated as Pd (OAc)₂)67mg and stirred at 90 ℃ for 14 hours. After a predetermined period of time, water was added to the mixture, extraction was performed with ethyl acetate, and the obtained organic layer was washed with water and saturated brine and dried over magnesium sulfate. The mixture was filtered, and the resulting filtrate was concentrated to give a brown oil. The oil was dissolved in toluene and purified by silica gel column chromatography using hexane and ethyl acetate. In the purification, the hexane ratio gradually decreased, so the ratio of hexane and ethyl acetate was changed from 5: 1 finally becomes 2: 1. thus, 4.3g of the objective pale yellow solid was obtained in a yield of 91%. The synthetic scheme (d-1) of step 1 is shown below.

[ chemical formula 36]

< step 2: synthesis of 4- (dibenzothiophen-4-yl) -2- (4, 4, 5, 5-tetramethyl-1, 3, 2-dioxolan-2-yl) phenol >

Subsequently, 0.31g of 2-chloro-4- (dibenzothiophen-4-yl) phenol synthesized in the above-mentioned step 1, 0.28g of pinacol diboron, 0.30g of potassium acetate (AcOK), 17mg of 2-dicyclohexylphosphino-2 ', 6' -dimethoxybiphenyl (S-Phos), and 2.5mL of 1, 4-dioxane were placed in a two-necked flask, and stirring was carried out under reduced pressure to degas, followed by nitrogen substitution with the air in the flask.

To the mixture was added tris (dibenzylideneacetone) dipalladium (0) (abbreviated as Pd)₂(dba)₃)18mg, and the resulting mixture was stirred at 100 ℃ for 7 hours. After a predetermined period of time, water was added to the mixture, extraction was performed with ethyl acetate, and the obtained organic layer was washed with water and saturated brine and dried over magnesium sulfate. The mixture was gravity filtered and the filtrate was concentrated to give a brown oil. Dissolving the oilPurification was performed by silica gel column chromatography using hexane and ethyl acetate (5: 1) as developing solvents in toluene, whereby 0.20g of the objective pale yellow solid was obtained in a yield of 50%. The synthetic scheme (d-2) of step 2 is shown below.

[ chemical formula 37]

< step 3: synthesis of 2, 5-dichloro-4- [ 2-hydroxy-5- (dibenzothiophen-4-yl) phenyl ] pyrimidine >

Subsequently, 0.21g of 4- (dibenzothiophen-4-yl) -2- (4, 4, 5, 5-tetramethyl-1, 3, 2-dioxaborolan-2-yl) phenol synthesized in the above-mentioned step 2, 13mg of triphenylphosphine, 0.10g of potassium acetate, 1.9mL of acetonitrile and 0.48mL of water were placed in a three-necked flask, and the flask was degassed by stirring under reduced pressure, and then the air in the flask was replaced with nitrogen. To the mixture were added 62. mu.L of 2, 4, 5-trichloropyrimidine and 7.0mg of palladium (II) acetate, and the mixture was stirred at room temperature for 18 hours. After a predetermined period of time, water was added to the mixture, extraction was performed with ethyl acetate, and the obtained organic layer was washed with water and saturated brine and dried over magnesium sulfate. The mixture was gravity filtered and the resulting filtrate was concentrated to give a brown oil. This oil was dissolved in toluene and purified by silica gel column chromatography using hexane and ethyl acetate (5: 1) as developing solvents, whereby 0.12g of the objective product was obtained as a pale yellow solid in a yield of 55%. The synthetic scheme (d-3) of step 3 is shown below.

[ chemical formula 38]

< step 4: synthesis of 2-chloro-8- (dibenzothiophen-4-yl) - [1] benzofuro [3,2-d ] pyrimidine

Then, 0.36g of 2, 5-dichloro-4- [ 2-hydroxy-5- (dibenzothiophen-4-yl) phenyl ] pyrimidine synthesized in the above-mentioned step 3 and 34mL of dimethylacetamide (abbreviated as DMAC) were placed in a two-necked flask, and the flask was degassed by stirring under reduced pressure, and then the air in the flask was replaced with nitrogen. To the mixture was added 0.21mg of copper (I) thiophene-2-carboxylate (abbreviated as CuTC), and the resulting mixture was stirred at 80 ℃ for 9.5 hours.

After a predetermined period of time, brine was added to the mixture, extraction was performed with ethyl acetate, and the obtained organic layer was washed with water and saturated brine and dried over magnesium sulfate. The mixture was gravity filtered and the filtrate was concentrated to give a yellow solid. This solid was dissolved in toluene, and purified by silica gel column chromatography using hexane and ethyl acetate (5: 1) as developing solvents, whereby 0.16g of the objective white solid was obtained in a yield of 50%. The synthetic scheme (d-4) of step 4 is shown below.

[ chemical formula 39]

< step 5: synthesis of 8- (dibenzothiophen-4-yl) -2- [3- (dibenzothiophen-4-yl) phenyl ] - [1] benzofuro [3,2-d ] pyrimidine (abbreviation: 8DBt-2mDBtPBfpm) >

Then, 0.10g of 2-chloro-8- (dibenzothiophen-4-yl) - [1] benzofuro [3,2-d ] pyrimidine synthesized in the above step 4, 99mg of 3- (dibenzothiophen-4-yl) phenylboronic acid, 0.17g of tripotassium phosphate, 2.7mL of diglyme, and 6.7mg of t-butanol were placed in a three-necked flask, and the flask was degassed by stirring under reduced pressure, and then the air in the flask was replaced with nitrogen. To the mixture were added 1.9mg of palladium (II) acetate and 6.0mg of bis (1-adamantyl) -n-butylphosphine, and the resulting mixture was stirred at 120 ℃ for 7.5 hours under a nitrogen stream, and then at 140 ℃ for 1.5 hours. After a predetermined period of time, water was added to the mixture, the precipitate was filtered with suction, and the residue was washed with ethanol.

The obtained residue was dissolved in heated toluene, and filtered using a filter aid containing celite, alumina, and celite in this order. The resulting solution was concentrated and dried, and recrystallized from toluene, whereby 0.040g of 8DBt-2mDBtPBfpm (abbreviation) white solid of the present invention was obtained in a yield of 24%. The synthetic scheme (d-5) of step 5 is shown below.

[ chemical formula 40]

The nuclear magnetic resonance spectroscopy of the obtained white solid is shown below (¹H-NMR). From the results, in this example, the organic compound 8DBt-2mDBtPBfpm represented by the structural formula (145) was obtained.

¹H-NMR.δ(CDCl₃)：7.42-7.52(m，4H)，7.59(t，3H)，7.64(d，1H)，7.69(t，1H)，7.82-7.85(m，3H)，7.90(d，1H)，8.12(dd，1H)，8.18-8.23(m，4H)，8.68(dt，1H)，8.70(sd，1H)，8.99(st，1H)，9.16(s，1H)。

< reference Synthesis example >

A method for synthesizing 4, 8-bis [3- (dibenzothiophen-4-yl) phenyl ] - [1] benzofuro [3,2-d ] pyrimidine (4, 8mDBtP2Bfpm) (structural formula (200)) as the benzofuropyrimidine compound described in example 5 is described in this reference synthesis example. The structure of 4, 8mDBtP2Bfpm is shown below.

[ chemical formula 41]

Step 1: synthesis of 8-chloro-4- [3- (dibenzothiophen-4-yl) phenyl ] - [1] benzofuro [3,2-d ] pyrimidine

First, 1.0g of 4, 8-dichloro [1]]Benzofuro [3,2-d]Pyrimidine, 2.6g of 3- (dibenzothiophen-4-yl) phenylboronic acid, 1.2g of potassium carbonate, 42mL of toluene, 4mL of ethanol, and 4mL of water were placed in a three-necked flask equipped with a reflux tube, the air in the flask was replaced with nitrogen, and 0.29g of bis (triphenylphosphine) palladium (II) dichloride (abbreviated as Pd (PPh): Pd (PPh)₃)₂Cl₂) The mixture was heated at 80 ℃ for 8 hours under a nitrogen stream. The resulting reaction mixture was filtered and usedWater and ethanol were washed, whereby 1.9g of the objective compound (gray solid) was obtained in a yield of 96%. The synthesis scheme (A-1) of step 1 is shown below.

[ chemical formula 42]

Further, nuclear magnetic resonance spectroscopy of a gray solid obtained in the above step 1 is shown below (¹H-NMR). This gave 8-chloro-4- [3- (dibenzothiophen-4-yl) phenyl]-[1]Benzofuro [3,2-d]A pyrimidine.

¹H-NMR.δ(TCE-d₂):7.48-7.52(m，2H)，7.63-7.71(m，4H)，7.77-7.80(t，1H)，7.85(d，1H)，7.96(d，1H)，8.22-8.23(m，2H)，8.28(s，1H)，8.65(d，1H)，8.96(s，1H)，9.29(s，1H)。

Step 2: synthesis of 4, 8-bis [3- (dibenzothiophen-4-yl) phenyl ] - [1] benzofuro [3,2-d ] pyrimidine (abbreviation: 4, 8mDBtP2Bfpm)

Subsequently, 1.7g of 8-chloro-4- [3- (dibenzothiophen-4-yl) phenyl ] - [1] benzofuro [3,2-d ] pyrimidine synthesized in the above step 1, 1.1g of 3- (dibenzothiophen-4-yl) phenylboronic acid, 1.6g of potassium phosphate, and 60mL of diethylene glycol dimethyl ether (abbreviated as "diglyme") were placed in a flask, the air in the flask was replaced with nitrogen, 90mg of palladium acetate and 0.29g of bis (1-adamantyl) -n-butylphosphine were added, and the mixture was heated at 160 ℃ for 12 hours under a nitrogen stream. The obtained reaction mixture was filtered, washed with water and ethanol in this order, and the obtained residue was filtered using a filter aid packed with celite, alumina, and celite in this order. 1.2g of 4, 8mDBtP2Bfpm (yellow white solid) were obtained in 47% yield by recrystallising the obtained solution. 1.2g of the obtained off-white solid was purified by sublimation using a gradient sublimation method. In sublimation purification, the solid was heated at 330 ℃ under a pressure of 2.6Pa and an argon gas flow rate of 5 mL/min. After purification by sublimation, 0.8g of the objective substance was obtained as a yellowish white solid in a recovery rate of 67%. The synthesis scheme (A-2) of step 2 is shown below.

[ chemical formula 43]

The nuclear magnetic resonance spectroscopy of the yellowish white solid obtained in the above step 2 is shown below (¹H-NMR). This indicated that 4, 8mDBtP2Bfpm was obtained.

¹H-NMR.δ(TCE-d₂):7.48-7.52(t，4H)，7.60(s，1H)，7.61(d，1H)，7.65-7.69(m，3H)，7.79-7.83(m，3H)，7.86-7.89(m，3H)，8.00(d，1H)，8.07(s，1H)，8.10(d，1H)，8.19-8.24(m，4H)，8.69-8.72(t，2H)，9.02(s，1H)，9.32(s，1H)。

[ example 7]

Synthesis example 5

In this synthesis example, a method for synthesizing an organic compound 4- [3- (dibenzothiophen-4-yl) phenyl ] -8- (naphthalen-1-yl) - [1] benzofuro [3,2-d ] pyrimidine (abbreviated as 8 α N-4mDBtPBfpm) according to an embodiment of the present invention represented by the structural formula (103) of embodiment 1 will be described, and the structure of 8 α N-4mDBtPBfpm will be shown below.

[ chemical formula 44]

< step 1: synthesis of 2-hydroxy-5- (naphthalen-1-yl) benzonitrile >

First, 2.97g of 6-bromo-2-hydroxybenzonitrile, 2.8g of naphthalene-1-boronic acid, tris (2-methylphenyl) phosphine (P (o-tol)₃)0.184g, potassium carbonate 4.15g, toluene 56mL, ethanol 19mL and water 15mL were placed in a three-necked flask, and the flask was degassed by stirring under reduced pressure, and then the air in the flask was replaced with nitrogen. Palladium (II) acetate (abbreviated as Pd (OAc)) is added to the mixture₂)69.3mg, the mixture was stirred at 100 ℃ for 17.5 hours. The resulting reaction mixture was extracted with ethyl acetate, and the resulting organic layer was washed with water and saturated brine, followed by use ofThe magnesium sulfate was dried. The mixture was gravity filtered and the filtrate was concentrated to give a light brown solid. The solid was dissolved in a heated mixed solvent of toluene and ethyl acetate, and purified by silica gel column chromatography using hexane and ethyl acetate as developing solvents. In the purification, the hexane ratio gradually decreased, and thus the ratio of hexane and ethyl acetate was changed from 3: 1 finally becomes 1: 1. thus, 3.43g of the objective pale yellow solid was obtained in a yield of 93%. The synthetic scheme (e-1) of step 1 is shown below.

[ chemical formula 45]

< step 2: synthesis of 3-amino-5- (naphthalen-1-yl) benzo [ b ] furan-2-carboxylic acid ethyl group >

Then, 3.43g of 2-hydroxy-5- (naphthalen-1-yl) benzonitrile synthesized in the above step 1 and 3.87g of potassium carbonate were put in a three-necked flask, and the air in the flask was replaced with nitrogen. To the mixture were added ethyl bromoacetate 3.51g and 18mL of N, N-Dimethylformamide (DMF), and the mixture was stirred at 100 ℃ for 5 hours. The resulting reaction mixture was stirred in ice water for 1 hour, followed by suction filtration to obtain 4.97g of a dark brown residue as an objective substance. The synthetic scheme (e-2) of step 2 is shown below.

[ chemical formula 46]

< step 3: synthesis of 8- (naphthalen-1-yl) - [1] benzofuro [3,2-d ] pyrimidin-4 (3H) -one >

4.97g of the brown concentrate obtained in step 2 and 20mL of formamide were placed in an eggplant-shaped flask, and the mixture was heated at 150 ℃. To the mixture was added 2.92g of formamidine acetate, and the mixture was stirred at 160 ℃ for 6.5 hours. Water was added to the obtained reaction mixture, followed by suction filtration to obtain a residue. The residue was washed with ethyl acetate and hexane to obtain 2.98g of a pale brown solid of the objective compound (yield from step 2 to step 3: 68%). The synthetic scheme (e-3) of step 3 is shown below.

[ chemical formula 47]

< step 4: synthesis of 4-chloro-8- (naphthalen-1-yl) - [1] benzofuro [3,2-d ] pyrimidine

2.98g of 8- (naphthalen-1-yl) - [1] benzofuro [3,2-d ] pyrimidin-4 (3H) -one synthesized in step 3 and 74. mu.L of N, N-Dimethylformamide (DMF) were put in a three-necked flask, and the mixture was stirred. To the mixture was added 31.8g of phosphorus oxychloride, and the mixture was stirred at 90 ℃ for 11 hours. Phosphorus oxychloride was removed from the resulting reaction mixture by distillation, and the mixture was put into ice water, neutralized with a saturated aqueous solution of sodium hydrogencarbonate, and stirred for 1 hour. The mixture was suction-filtered, and the residue was washed with ethanol, whereby 3.12g of the objective product was obtained as a pale brown solid in a yield of 99%. The synthetic scheme (e-4) of step 4 is shown below.

[ chemical formula 48]

< Synthesis of step 5: 8 α N-4mDBtPBfpm >

4-chloro-8- (naphthalene-1-yl) - [1]]Benzofuro [3,2-d]3.12g of pyrimidine, 3.44g of 3- (dibenzothiophen-4-yl) phenylboronic acid, 2.61g of potassium carbonate, 36mL of toluene, 12mL of ethanol, and 9.5mL of water were placed in a three-necked flask, and the flask was degassed by stirring under reduced pressure, and then the air in the flask was replaced with nitrogen. To the mixture was added tetratriphenylphosphine palladium (II) (Pd (PPh)₄)₂)0.324g, the mixture was stirred at 100 ℃ for 27.5 hours. The resulting reaction mixture was added with water and filtered with suction. The obtained residue was washed with water and ethyl acetate, dissolved in heated toluene, and filtered using a filter aid containing celite, alumina, and celite in this order. Concentrating and drying the obtained solution, recrystallizing with toluene, fromThis gave 3.0g of the desired product as a white solid in a yield of 57%. 3.00g of the white solid was purified by sublimation using a gradient sublimation method. In sublimation purification: the solid was heated at 290 ℃ under a pressure of 3.7Pa and an argon gas flow rate of 15 mL/min. After purification by sublimation, 1.86g of the objective white solid was obtained in a recovery rate of 62%. The synthetic scheme (e-5) of step 5 is shown below.

[ chemical formula 49]

The following shows the nuclear magnetic resonance method of the white solid obtained in the above step 5(¹H-NMR). In addition, FIG. 31 shows¹From this, 8 α N-4mDBtPBfpm was obtained.

¹H-NMR.δ(CDCl₃)：7.45-7.55(m，5H)，7.59(t，1H)，7.63-7.67(m，2H)，7.82(t，1H)，7.85-8.00(m，7H)，8.24(d，2H)，8.44(s，1H)，8.50(d，1H)，9.08(s，1H)，9.32(s，1H)。

[ example 8]

Synthesis example 6

In this synthesis example, a method for synthesizing an organic compound 4- [3' - (dibenzothiophen-4-yl) biphenyl-3-yl ] -8- (naphthalen-2-yl) - [1] benzofuro [3,2-d ] pyrimidine (abbreviated as 8 β N-4mDBtPBfpm) according to an embodiment of the present invention represented by the structural formula (116) of embodiment 1 will be described, and the structural formula of 8 β N-4mDBtPBfpm will be shown below.

[ chemical formula 50]

< step 1: synthesis of 8-chloro-4- [3' - (dibenzothiophen-4-yl) biphenyl-3-yl ] - [1] benzofuro [3,2-d ] pyrimidine >

4, 8-dichloro [1]]Benzofuro [3,2-d]7.65g of pyrimidine, 17.0g of 3' - (dibenzothiophen-4-yl) biphenyl-3-boronic acid, 12.4g of potassium carbonate, 360mL of toluene, 36mL of ethanol and water45mL of the solution was put in a three-necked flask, and the flask was degassed by stirring under reduced pressure, and then the air in the flask was replaced with nitrogen. To the mixture was added bis (triphenylphosphine) palladium (II) dichloride (abbreviated as Pd (PPh))₃)₂Cl₂)2.25g, the mixture was stirred at 80 ℃ for 6 hours. The obtained reaction mixture was added with water, filtered under suction, and the obtained residue was washed with water and ethanol. This residue was dissolved in heated toluene, and filtered using a filter aid containing celite, alumina, and celite in this order. The obtained solution was concentrated and dried, and recrystallization was performed using toluene, whereby 14.7g of the objective pale yellow solid was obtained in a yield of 85%. The synthesis scheme (f-1) of step 1 is shown below.

[ chemical formula 51]

< Synthesis of step 2: 8 β N-4mDBtPBfpm >

Then, the 8-chloro-4- [3' - (dibenzothiophen-4-yl) biphenyl-3-yl group synthesized in the above step 1 is added]-[1]Benzofuro [3,2-d]7.01g of pyrimidine, 3.13g of naphthalene-2-boronic acid, 5.93g of cesium fluoride and 130mL of mesitylene were placed in a three-necked flask, and the mixture was degassed by stirring under reduced pressure, and then the air in the flask was replaced with nitrogen. To the mixture was added tris (dibenzylideneacetone) dipalladium (0) (Pd)₂(dba)₃)0.358g and 2' - (dicyclohexylphosphino) acetophenone vinyl ketal 0.283g, and the mixture was stirred at 120 ℃ for 17.5 hours. 0.358g of tris (dibenzylideneacetone) dipalladium (0) and 0.283g of 2' - (dicyclohexylphosphino) acetophenone vinyl ketal were added to the mixture, and the mixture was stirred at 120 ℃ for 16 hours.

The reaction mixture was subjected to suction filtration by adding water, and the obtained residue was washed with water and ethyl acetate, dissolved in heated toluene, and filtered by using a filter aid comprising celite, alumina and celite in this order, the obtained solution was concentrated and dried, and recrystallized by using toluene, whereby 6.75g of a white solid as a target substance of 8 β N-4mDBtPBfpm (abbreviation) of the present invention was obtained at a yield of 82%, 2.47g of the white solid was subjected to sublimation purification by a gradient sublimation method, wherein the solid was heated at 340 ℃ under a pressure of 3.7Pa and an argon gas flow rate of 15 mL/min, and 2.20g of a light brown solid as a target substance was obtained at a recovery rate of 89% after sublimation purification, and the synthesis scheme (f-2) of step 2 was shown below.

[ chemical formula 52]

In addition, the following shows the nuclear magnetic resonance method of the pale brown solid obtained in the above step 2: (¹H-NMR). In addition, FIG. 32 shows¹From this, 8 β N-4mDBtPBfpm was obtained.

¹H-NMR.δ(CDCl₃)：7.46-7.57(m，4H)，7.61-7.63(m，2H)，7.70(t，1H)，7.76(t，1H)，7.79-7.83(m，3H)，7.86(d，2H)，7.91-7.95(m，3H)，8.00(d，1H)，8.05(d，1H)，8.18(d，2H)，8.21-8.24(m，2H)，8.65-8.66(m，2H)，8.99(s，1H)，9.33(s，1H)。

[ example 9]

In this example, a light-emitting element 6 and a light-emitting element 7 were manufactured as a light-emitting element according to an embodiment of the present invention, 8 α N to 4mDBtPBfpm (structural formula (103)) described in example 7 was used for the light-emitting layer in the light-emitting element 6, 8 β N to 4mDBtPBfpm (structural formula (116)) described in example 8 was used for the light-emitting layer in the light-emitting element 7, and the results of measuring the characteristics of the light-emitting elements 6 and 7 are shown below.

The element structure of the light-emitting element used in this embodiment is the same as that described in embodiment 4 with reference to fig. 18. Table 5 shows the specific structure of each layer in the element structure. The chemical formula of the material used in this example is shown below.

[ Table 5]

*8αN-4mDBtPBfpm:PCCP:[Ir(ppy)₂(4dppy)](0.6:0.4:0.140nm)

**8βN-4mDBtBPBfpm:PCCP:[Ir(ppy)₂(4dppy)](0.6:0.4:0.140nm)

[ chemical formula 53]

Operating characteristics of light-emitting element

The operating characteristics of the manufactured light-emitting elements 6 and 7 were measured. In addition, the measurement was performed at room temperature. Fig. 33 to 36 show the results.

Furthermore, Table 6 shows 1000cd/m²Main initial characteristic values of the respective light emitting elements in the vicinity.

[ Table 6]

From the above results, it is understood that each of the light-emitting elements manufactured in this example has good element characteristics.

FIG. 37 shows the signal at 2.5mA/cm²Current density of (a) emission spectrum when a current is applied to each light emitting element. As shown in fig. 37, the emission spectrum of each light-emitting element has a peak around 558nm, and the peak may be derived from [ ir (ppy) ] included in the light-emitting layer 913₂(4dppy)]The light emission of (1).

Next, reliability tests of the light-emitting elements 6 and 7 were performed. Fig. 38 shows the results of the reliability test. In fig. 38, the vertical axis represents the normalized luminance (%) with the initial luminance as 100%, and the horizontal axis represents the driving time (h) of the element. In the reliability test, the light emitting element was driven at a constant current of 2 mA.

From the results of the reliability test, it is understood that both the light-emitting element 6 and the light-emitting element 7 according to the embodiment of the present invention are excellent in reliability, and that the organic compounds 8 α N-4mDBtPBfpm (structural formula (103)) and 8 β N-4 mdbtbpfpm (structural formula (116)) according to the embodiment of the present invention are effective for increasing the lifetime of the light-emitting element.

[ example 10]

In this example, a light-emitting element 8 was manufactured as a light-emitting element according to one embodiment of the present invention. In the light-emitting element 8, 8DBt-2mDBtPBfpm (structural formula (145)) described in example 6 was used for the light-emitting layer. The measurement results of the characteristics of the light-emitting element 8 are shown below.

The element structure of the light-emitting element used in this embodiment is the same as that described in embodiment 4 with reference to fig. 18. Table 7 shows the specific structure of each layer in the element structure. The chemical formula of the material used in this example is shown below.

[ Table 7]

*8DBt-2mDBtPBfpm:PCCP:[Ir(ppy)₂(mdppy)](0.7:0.3:0.140nm)

[ chemical formula 54]

Operating characteristics of light-emitting element

The operating characteristics of the fabricated light emitting element 8 were measured. In addition, the measurement was performed at room temperature. Fig. 39 to 42 show the results.

Furthermore, Table 8 shows 1000cd/m²The main initial characteristic values of the nearby light-emitting elements 8.

[ Table 8]

From the above results, it is understood that the light-emitting element 8 manufactured in this embodiment has good element characteristics.

FIG. 43 shows the signal at 2.5mA/cm²The current density of (a) is an emission spectrum when a current is applied to the light emitting element 8. As shown in fig. 43, the emission spectrum of the light-emitting element 8 has a peak around 524nm, which may be derived from [ ir (ppy) ] included in the light-emitting layer 913₂(mdppy)]The light emission of (1).

[ example 11]

Synthesis example 7

In this synthesis example, a method for synthesizing an organic compound 8- (dibenzothiophen-4-yl) -4- [3' - (dibenzothiophen-4-yl) biphenyl-3-yl ] - [1] benzofuro [3,2-d ] pyrimidine (abbreviated as 8DBt-4 mDBtPBfpm) (structural formula (151)) according to an embodiment of the present invention will be described. The structural formula of 8DBt-4 mDBtPBfpm is shown below.

[ chemical formula 55]

Reacting 8-chloro-4- [3' - (dibenzothiophene-4-yl) biphenyl-3-yl]-[1]Benzofuro [3,2-d]7.00g of pyrimidine, 3.56g of dibenzothiophene-4-boronic acid, 0.281g of 2' - (dicyclohexylphosphino) acetophenone vinyl ketal, 6.00g of cesium fluoride, and 65mL of mesitylene were placed in a three-necked flask, and the mixture was degassed by stirring under reduced pressure, and then the air in the flask was replaced with nitrogen. To the mixture was added tris (dibenzylideneacetone) dipalladium (0) (Pd)₂(dba)₃)0.359g, and the mixture was stirred at 120 ℃ for 1 hour. To the mixture was added 65mL of degassed mesitylene, and the mixture was stirred at 120 ℃ for 9.5 hours. Further, 30mL of degassed mesitylene was added to the mixture, and the mixture was stirred at 120 ℃ for 7 hours. Adding Pd to the mixture₂(dba)₃0.360g and 0.284g of 2' - (dicyclohexylphosphino) acetophenone vinyl ketal were stirred at 130 ℃ for 15 hours, and then at 140 ℃ for 6 hours. To the mixture were added 2.37g of dibenzothiophene-4-boronic acid and Pd₂(dba)₃0.359g and 2' - (dicyclohexylphosphino) acetophenone vinyl ketal 0.283g, were stirred at 140 ℃ for 40 hours. To the obtainedThe resulting reaction mixture was added with water, filtered with suction, and the obtained residue was washed with water and ethyl acetate. This residue was dissolved in heated toluene, and filtered using a filter aid containing celite, alumina, and celite in this order. The resulting solution was concentrated and dried, and recrystallized using toluene, whereby 5.56g of 8DBt-4 mDBtPBfpm (abbreviation) as a white solid was obtained in a yield of 62%. 1.95g of the white solid was purified by sublimation using a gradient sublimation method. In the sublimation purification conditions, the solid was heated at 355 ℃ under a pressure of 2.8Pa and an argon gas flow rate of 15 mL/min. After purification by sublimation, 1.46g of the objective substance as a pale brown solid was obtained in a recovery rate of 75%. The following shows the synthesis scheme (g-1).

[ chemical formula 56]

The following shows the nuclear magnetic resonance method of a light brown solid obtained by the above-mentioned step (¹H-NMR). From this, 8DBt-4 mDBtPBfpm was obtained.

¹H-NMR.δ(CDCl₃)：7.47-7.51(m，4H)，7.59-7.65(m，4H)，7.70(t，1H)，7.76-7.87(m，6H)，7.95(d，1H)，8.09(d，1H)，8.21-8.24(m，5H)，8.66-8.68(m，2H)，9.01(s，1H)，9.34(s，1H)。

The present application is based on japanese patent application No. 2017-122567 filed by the japanese patent office on 22/6/2017, the entire contents of which are incorporated herein by reference.

Description of the symbols

101: first electrode, 102: second electrode, 103: EL layer, 103a, 103b, 103 c: EL layer, 104: charge generation layer, 111a, 111 b: hole injection layer, 112a, 112 b: hole transport layer, 113a, 113b, 113 c: light-emitting layers, 114a, 114 b: electron transport layer, 115a, 115 b: electron injection layer, 200R, 200G, 200B: optical distance, 201: first substrate, 202: transistor (FET), 203R, 203G, 203B, 203W: light-emitting element, 204: EL layer, 205: second substrate, 206R, 206G, 206B: color filters, 206R ', 206G ', 206B ': color filter, 207: first electrode, 208: second electrode, 209: black layer (black matrix), 210R, 210G: conductive layer, 301: first substrate, 302: pixel portion, 303: driver circuit portion (source line driver circuit), 304a, 304 b: driver circuit portion (gate line driver circuit), 305: sealant, 306: second substrate, 307: lead, 308: FPC, 309: FET, 310: FET, 311: FET, 312: FET, 313: first electrode, 314: insulator, 315: EL layer, 316: second electrode, 317: light-emitting element, 318: space, 900: substrate, 901: first electrode, 902: EL layer, 903: second electrode, 911: hole injection layer, 912: hole-transport layer, 913: light-emitting layer, 914: electron transport layer, 915: electron injection layer, 4000: lighting device, 4001: substrate, 4002: light-emitting element, 4003: substrate, 4004: first electrode, 4005: EL layer, 4006: second electrode, 4007: electrode, 4008: electrode, 4009: auxiliary wiring, 4010: insulating layer, 4011: sealing substrate, 4012: sealant, 4013: desiccant, 4015: diffusion plate, 4100: lighting device, 4200: lighting device, 4201: substrate, 4202: light-emitting element, 4204: first electrode, 4205: EL layer, 4206: second electrode, 4207: electrode, 4208: electrode, 4209: auxiliary wiring, 4210: insulating layer, 4211: sealing substrate, 4212: sealant, 4213: barrier film, 4214: planarizing film, 4215: diffuser plate, 4300: lighting device, 5101: lamp, 5102: hub, 5103: vehicle door, 5104: display unit, 5105: steering wheel, 5106: gear lever, 5107: seat, 5108: interior rearview mirror, 7000: case, 7001: display unit, 7002: second display portion, 7003: speaker, 7004: LED lamp, 7005: operation keys, 7006: connection terminal, 7007: sensor, 7008: microphone, 7009: switch, 7010: infrared port, 7011: recording medium reading unit, 7012: support portion, 7013: earphone, 7014: antenna, 7015: shutter button, 7016: image receiving unit, 7018: support 7020: camera, 7019: microphone, 7021: external connection portions 7022, 7023: operation buttons, 7024: connection terminal, 7025: watchband, 7026: watch band buckle, 7027: icon representing time, 7028: other icons, 8001: lighting device, 8002: lighting device, 8003: lighting device, 8004: lighting device, 9310: portable information terminal, 9311: display portion, 9312: display region, 9313: hinge portion, 9315: a housing.