阅读说明：本技术 有机化合物、有机发光元件、显示装置、成像装置、电子装置、照明装置和移动体 (Organic compound, organic light-emitting element, display device, imaging device, electronic device, lighting device, and moving object ) 是由 山田直树 镰谷淳 西出洋祐 宫下广和 于 2019-08-09 设计创作，主要内容包括：本发明涉及有机化合物、有机发光元件、显示装置、成像装置、电子装置、照明装置和移动体。一种发出长波长红光的有机化合物由式(1)表示。在式(1)中,R<Sub>1</Sub>至R<Sub>24</Sub>各自独立地选自由氢原子、卤素原子、取代或未取代的烷基、取代或未取代的烷氧基、取代或未取代的氨基、取代或未取代的芳基、取代或未取代的杂环基、取代或未取代的芳氧基、甲硅烷基和氰基组成的组。<Image he="286" wi="700" file="DDA0002161307610000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention relates to an organic compound, an organic light-emitting element, a display device, an imaging device, an electronic device, an illumination device, and a moving body. An organic compound emitting long wavelength red light is represented by formula (1). In the formula (1), R 1 To R 24 Each independently selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstitutedA substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryloxy group, a silyl group, and a cyano group.)

1. An organic compound represented by formula (1):

characterized in that R is₁To R₂₄Each independently selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryloxy group, a silyl group, and a cyano group.

2. The organic compound according to claim 1, wherein R in formula (1)₁To R₂₄At least one of which is a phenyl group, and the phenyl group has a substituent at the ortho-position of the phenyl group.

3. The organic compound according to claim 1, wherein R in formula (1)₁₃、R₁₄、R₁₉And R₂₀At least two of which are each aryl.

4. The organic compound according to claim 1, wherein R in formula (1)₁₃To R₁₄At least one of R₁₉To R₂₀And R₈Each is an aryl group.

5. The organic compound according to claim 1, wherein R in formula (1)₁₃、R₁₄、R₁₉And R₂₀At least two of which are each a phenyl group,

said phenyl group having a substituent at least at the ortho position to the phenyl group, and

the substituent is selected from the group consisting of a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, and a cyano group.

6. The organic compound of claim 5, wherein R₁₃And R₁₄And R, and₁₉and R₂₀Each of which is a phenyl group,

said phenyl group having a substituent at least at the ortho position to the phenyl group, and

the substituent is selected from the group consisting of a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, and a cyano group.

7. An organic light-emitting element comprising:

a pair of electrodes; and

an organic compound layer disposed between the pair of electrodes,

characterized in that the organic compound layer comprises the organic compound according to claim 1.

8. The organic light-emitting element according to claim 7, wherein the organic compound layer comprises a light-emitting layer.

9. The organic light-emitting element according to claim 8, wherein the organic light-emitting element emits red light.

10. The organic light-emitting element according to claim 9, wherein the organic compound layer further comprises an additional light-emitting layer stacked over the light-emitting layer, and the additional light-emitting layer emits light of a color different from that of light emitted from the light-emitting layer.

11. The organic light-emitting element according to claim 10, wherein the organic light-emitting element emits white light.

12. A display device comprising a plurality of pixels, wherein each of the plurality of pixels comprises the organic light-emitting element according to claim 7 and a transistor connected to the organic light-emitting element.

13. The display device according to claim 12, comprising a color filter on a light emitting side of each pixel.

14. An imaging device, comprising:

an optical unit having a plurality of lenses;

an imaging element that receives light that has passed through the optical unit; and

a display unit for displaying an image, wherein the display unit displays an image,

characterized in that the display unit displays an image captured by the imaging element, an

The display unit includes the organic light-emitting element according to claim 7.

15. An electronic device, comprising:

a housing;

a communication unit that communicates with the outside; and

a display unit for displaying the image of the object,

characterized in that the display unit comprises the organic light-emitting element according to claim 7.

16. An illumination device, comprising:

a light source; and

a light-diffusing unit or an optical film,

characterized in that the light source comprises the organic light-emitting element according to claim 7.

17. A mobile body, comprising:

a main body; and

a lighting fixture disposed on the body,

wherein the lighting fixture comprises the organic light-emitting element according to claim 7.

Technical Field

The present disclosure relates to an organic compound, and an organic light-emitting element, a display device, an imaging device, an electronic device, an illumination device, and a moving body that use the organic compound and have high color purity.

Background

An organic light-emitting element (also referred to as an "organic electroluminescent element" or an "organic EL element") is an electronic element including a pair of electrodes and an organic compound layer provided between the electrodes. Electrons and holes are injected from the pair of electrodes, thereby generating excitons of the light-emitting organic compound in the organic compound layer. When the excitons return to their ground state, the organic light-emitting element emits light.

Recently, organic light emitting elements have made remarkable progress. For example, a low driving voltage, a variety of light emitting wavelengths, a high-speed response, and a reduction in thickness and weight of the light emitting device can be achieved.

The standards of sRGB and AdobeRGB are used as a color reproduction range used in displays, and materials for reproducing such colors have been desired. Recently, BT-2020 has been proposed as a standard for further expanding the color reproduction range.

Hitherto, compounds having good light emitting properties have been actively created. Japanese patent laid-open No. 2013-043846 (hereinafter referred to as patent document 1) discloses a compound 1-A represented by the following structural formula.

An organic light-emitting element using the compound described in patent document 1 may have difficulty in reproducing red chromaticity coordinates (0.71,0.29) in the color reproduction range of BT-2020. Thus, there has been a need for compounds that emit red light at longer wavelengths. It is known that longer light emission wavelengths of organic compounds can be realized by providing a substituent. However, providing a substituent to change the wavelength is not preferable because the stability of the organic compound may be reduced.

Disclosure of Invention

The present disclosure provides an organic compound having a basic skeleton that emits red light of a longer wavelength.

An organic compound according to one embodiment of the present disclosure is represented by formula (1).

In the formula (1), R₁To R₂₄Each independently selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryloxy group, a silyl group, and a cyano group.

ADVANTAGEOUS EFFECTS OF INVENTION

Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

Drawings

FIG. 1 includes structural formulae of the molecules.

Fig. 2 is a schematic cross-sectional view showing an example of a display device including an organic light-emitting element according to the present embodiment and a transistor electrically connected to the organic light-emitting element.

Fig. 3 is a schematic diagram showing an example of a display device according to the present embodiment.

Fig. 4A is a schematic diagram showing an example of the imaging apparatus according to the present embodiment.

Fig. 4B is a schematic diagram showing an example of a mobile device according to the present embodiment.

Fig. 5A is a schematic diagram showing an example of a display device according to the present embodiment.

Fig. 5B is a schematic diagram showing an example of a foldable display device.

Fig. 6A is a schematic view showing an example of the lighting device according to the present embodiment.

Fig. 6B is a schematic diagram showing an automobile as an example of the moving body according to the present embodiment.

Detailed Description

The organic compound according to the present embodiment is an organic compound represented by the following general formula (1). The organic compound represented by the general formula (1) is also referred to as an organic compound according to the present embodiment or an organic compound according to the present disclosure.

In the general formula (1), R₁To R₂₄Each independently selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryloxy group, a silyl group, and a cyano group.

In this embodiment, R in the general formula (1)₁To R₂₄Preferably each independently selected from a hydrogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group.

From R₁To R₂₄Examples of halogen atoms represented include, but are not limited to, fluorine, chlorine, bromine, and iodine.

From R₁To R₂₄Examples of the alkyl group represented include alkyl groups having 1 to 10 carbon atoms. More specifically, examples thereof include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, sec-butyl, octyl, cyclohexyl, 1-adamantyl and 2-adamantyl.

From R₁To R₂₄Examples of the alkoxy group represented include alkoxy groups having 1 to 10 carbon atoms. More specifically, examples thereof include, but are not limited to, methoxy, ethoxy, propoxy, 2-ethyl-octyloxy, and benzyloxy.

From R₁To R₂₄Examples of the amino group represented include an amino group having an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 18 carbon atoms as a substituent. The amino group may have two alkyl groups, two aryl groups, or an alkyl group and an aryl group. In particular, the amino group preferably has two aryl groups. More specifically, examples thereof include, but are not limited toN-methylamino, N-ethylamino, N-dimethylamino, N-diethylamino, N-methyl-N-ethylamino, N-benzylamino, N-methyl-N-benzylamino, N-dibenzylamino, anilino, N-diphenylamino, N-dinaphthylamino, N-difluorenylamino, N-phenyl-N-tolylamino, N-ditolylamino, N-methyl-N-phenylamino, N-dianisilaminogroup, N-mesityl-N-phenylamino, N-ditrimethylphenylamino, N-phenyl-N- (4-tert-butylphenyl) amino, N-di-mesitylamino, N-phenyl-N- (4-tert-butylphenyl) amino, N-phenyl-N- (4-trifluoromethylphenyl) amino and N-piperidinyl.

From R₁To R₂₄Examples of the aryl group represented include aryl groups having 6 to 18 carbon atoms. More specifically, examples thereof include, but are not limited to, phenyl, naphthyl, indenyl, biphenyl, terphenyl and fluorenyl, phenanthryl and triphenylenyl.

From R₁To R₂₄Examples of the heterocyclic group represented include heterocyclic groups having 3 to 15 carbon atoms. More specifically, examples thereof include, but are not limited to, pyridyl, oxazolyl, oxadiazolyl, thiazolyl, thiadiazolyl, carbazolyl, acridinyl, phenanthrolinyl (phenanthrolyl), dibenzofuranyl, and dibenzothiophenyl.

From R₁To R₂₄Examples of the aryloxy group represented include aryloxy groups having 6 to 18 carbon atoms, and examples thereof include, but are not limited to, phenoxy and thiophenoxy.

From R₁To R₂₄Examples of silyl groups represented include, but are not limited to, trimethylsilyl and triphenylsilyl.

Examples of the substituent which may be further contained in the alkyl group, alkoxy group, amino group, aryl group, heterocyclic group and aryloxy group include, but are not limited to, alkyl groups having 1 to 10 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group and tert-butyl group; aralkyl groups having 6 to 18 carbon atoms such as benzyl; aryl groups having 6 to 18 carbon atoms such as phenyl and biphenyl; heterocyclic groups having 3 to 15 carbon atoms such as pyridyl and pyrrolyl; amino groups such as dimethylamino, diethylamino, dibenzylamino, diphenylamino, and ditolylamino; alkoxy groups having 1 to 10 carbon atoms such as methoxy, ethoxy, and propoxy; aryloxy groups having 6 to 18 carbon atoms such as phenoxy group; halogen atoms such as fluorine, chlorine, bromine and iodine; and a cyano group.

In this embodiment, R in the formula (1)₁To R₂₄Preferably each independently selected from a hydrogen atom and a substituted or unsubstituted aryl group.

Herein, the basic skeleton is R of the compound represented by the above general formula (1)₁To R₂₄Each is a structure of a hydrogen atom.

Next, a method of synthesizing an organic compound according to the present embodiment will be described. The organic compound according to the present embodiment is synthesized by, for example, the following reaction scheme.

As shown in the above synthesis scheme, the organic compound according to the present embodiment is synthesized by using the compounds represented by the following (a) to (d).

(a) Acenaphthenequinone derivatives (D1) and (D4)

(b) Dibenzyl ketone derivatives (D2) and (D5)

(c) Naphthalene anthranilic acid derivative (3-amino-2-naphthoic acid derivative) (D3)

(d) Phenylanthranilic acid derivative (2-aminobenzoic acid derivative) (D6)

The desired organic compound represented by the general formula (1) can be obtained by appropriately providing substituents to the compounds represented by the above (a) to (d).

The organic compound according to the present embodiment is a stable organic compound that emits red light with high color purity due to the following features.

(i) The emission wavelength of the basic skeleton itself is in the long wavelength red range.

(ii) The structure of the basic skeleton consists of hydrocarbon elements.

(iii) The quantum yield is high due to the high transition dipole moment.

Hereinafter, these features will be described.

In the present embodiment, the molecular structure, HOMO, oscillator strength, dihedral angle, and binding energy are calculated and determined by using the following molecular orbital calculation. HOMO is an abbreviation for "highest occupied molecular orbital," representing the energy level of the highest occupied molecular orbital.

The Density Functional Theory (DFT) which has been widely used at present is used as a calculation technique for molecular orbital calculation. B3LYP was used as the generic function and 6-31G as the basis function (basis function). The calculation was performed by using Gaussian09(Gaussian09, review c.01, m.j.frisch, g.w.trucks, h.b.schlegel, g.e.scrimeria, m.a.robb, j.r.cheeseman, g.scalmani, v.barone, b.menneuci, g.a.petersson, h.nakatsuji, m.caristo, x.li, h.p.h.hrachi, a.f.izmasovo, j.bloino, g.zheng, j.milhnsonneberg, m.hada, m.ehara, k.tokyouda, j, j.hakukukukukukuyau, j.h.h.r.h.r.t.m.k.t.t.m.k.g.t.m.g.t.m.t.g.r.t.g.c, m.c.t.g.c.t.t.t.t.t.g.c.t.t.t.c.t.g.t.t.c.t.g.c.g.c.c.g.c.r.t.t.c.r.g.g. r.t.g.t.c.g.c.g.t.t.g.g.g.g.t.t.t.c.g.t.t.t.g.g.g.t.c.g.c.c.g.g.g.g.g.t.t.t.g. g.g.g. g. r.c.c.c.g. g. r.g. g. g.

(i) The emission wavelength of the basic skeleton itself is in the long wavelength red range.

In the creation of the organic compound represented by the general formula (1), the inventors of the present disclosure focused on the basic skeleton itself. Specifically, the molecules are designed such that the wavelength of light emission due to the basic skeleton is within a desired wavelength range.

In the present embodiment, the desired wavelength range is the red range. Specifically, in the dilute solution, the maximum peak wavelength is in the range of 610nm or more and 640nm or less.

The light emission wavelength range of the organic compound according to the present embodiment will be described while being compared with a reference compound having a structure similar to that of the organic compound according to the present embodiment. Here, the reference compound is comparative compound 1-a, which is a compound described in patent document 1 and is shown in table 1 below. Comparison of emission wavelengths was performed by using compounds each having three phenyl groups in addition to the basic skeleton. The reason is to reduce the influence of concentration quenching by suppressing the stacking of molecules. Since the phenyl group is located at a substitution position having a small influence on the conjugation, the phenyl group does not significantly influence the emission wavelength. That is, light emission close to light emission caused by the basic skeleton itself is realized.

The inventors of the present disclosure compared the emission wavelengths between comparative compound 1-a and exemplary compound a3 according to the present embodiment. Table 1 shows the results. The measurement of the luminescence wavelength was performed by photoluminescence measurement of a diluted toluene solution at an excitation wavelength of 350nm at room temperature using a spectrofluorometer F-4500 manufactured by Hitachi, ltd.

TABLE 1

Referring to table 1, the luminescent color of comparative compound 1-a was red but not in the desired wavelength range. Specifically, the color purity of the comparative compound 1-a is lower than that of the organic compound according to the present embodiment. In contrast, since the maximum peak wavelength of the example compound A3 is within a desired range, the example compound A3 exhibits a long-wavelength red emission color suitable for a display standard of red, such as BT-2020. The basic skeleton of the organic compound according to the present embodiment can exhibit light emission having high color purity and capable of reproducing deep red. The chromaticity coordinates of red will be described in detail in the embodiments.

(ii) The structure of the basic skeleton consists of hydrocarbon elements.

The compound represented by the general formula (1) according to the present embodiment has a basic skeleton composed of hydrocarbons. The substituents are also preferably those composed of hydrocarbons. As for the realization of a longer light emission wavelength, a longer light emission wavelength of a compound can be realized by utilizing the action of electron donating property, for example, by bonding an amino group or the like in a molecular structure. However, when a compound having an unstable bond with a low binding energy such as an amino group is used as a light-emitting material for forming an organic EL element, the compound is likely to deteriorate during operation of the element and is likely to adversely affect the durability of the organic EL element.

In contrast, the compound represented by the general formula (1) according to the present embodiment is a compound composed of hydrocarbons, and thus has high binding energy. Therefore, when the compound represented by the general formula (1) is used for an organic EL element, the organic EL element has high durability.

For example, referring to the compounds A-1, A-2 and B-1 shown below, the bonds having low binding stability are a bond connecting a carbazole ring with a phenyl group, and a bond connecting an amino group with a phenyl group (nitrogen-carbon bond). As shown in the compound B-1, the bond connecting carbon to carbon has higher binding stability than the above bond.

(iii) The quantum yield is high due to the high transition dipole moment.

In the extension of the basic skeleton to achieve longer wavelengths, the inventors of the present disclosure focused on the position where benzene rings are fused. In order to achieve a longer wavelength of comparative compound 1-a described in patent document 1, various positions can be considered as positions where benzene rings are condensed. It has been found that, in particular, as shown in the exemplified compound a3, when the benzene ring is condensed in the longest direction relative to the molecular axis molecular length, a significant effect due to a longer wavelength is obtained, and the intensity of the vibrator affecting the quantum yield is high.

The basic skeleton of the general formula (1) according to the present embodiment has a transition dipole moment in the longest direction of the molecular length with respect to the molecular axis. In the fusion of benzene rings, when benzene rings are fused so as to extend the length in this direction, a high effect of increasing the transition dipole moment is obtained.

TABLE 2

Further, an organic compound satisfying the following conditions (iv) and (v) is preferable as a compound used in the organic light emitting element. This is because when the conditions (iv) and (v) are satisfied, the effect of suppressing intermolecular stacking is enhanced, and improvement in sublimability and suppression of concentration quenching can be achieved. The improvement in sublimability can achieve higher purity of a material purified by sublimation, and production of an organic light-emitting element by vapor deposition. As a result, impurities contained in the organic light emitting element are reduced, thereby suppressing a decrease in light emission efficiency and a decrease in driving durability caused by the impurities. From the viewpoint of improving the light emission efficiency of the organic light-emitting element, it is preferable to suppress concentration quenching.

(iv) Organic compound in R₈、R₁₃、R₁₄、R₁₉And R₂₀Have a large substituent on any one of them. (v) The organic compound has a substituent covering the plane of the molecule.

These features will be described below.

(iv) Organic compound in R₈、R₁₃、R₁₄、R₁₉And R₂₀Have a large substituent on any one of them.

When the organic compound according to the present embodiment further has a substituent on the basic skeleton, crystallinity of the molecule itself due to intermolecular stacking can be reduced. The decrease in crystallinity causes suppression of intermolecular concentration quenching and improves sublimability.

The organic compound according to the present embodiment has a basic skeleton with high planarity. Therefore, when the organic compound has no substituent, intermolecular stacking tends to occur. Substitution positions in the basic skeleton that can effectively suppress intermolecular stacking will be described.

Table 3 shows the results of the dihedral angle calculated between the basic skeleton and the phenyl group, the degree of distortion estimated from the dihedral angle, and the magnitude of steric repulsion when the position of the structure represented by general formula (1) according to the present embodiment is substituted with a phenyl group.

In the case of substituent patterns 1 to 3, since steric repulsion between hydrogen atoms at ortho positions of the phenyl group and hydrogen atoms of the basic skeleton is large, the twist of the phenyl group is large. Thus, planarity of the entire molecule is lost. This effect suppresses intermolecular stacking and reduces crystallinity, resulting in suppression of intermolecular concentration quenching and improvement of sublimability.

TABLE 3

(v) The organic compound having a substituent covering the plane of the molecule

In the present embodiment, when the substituent is an alkyl group, for example, methyl, ethyl, propyl, butyl, hexyl, and octyl are preferable. Particularly preferred are the sterically large isopropyl and tert-butyl groups. When the substituent is an aryl group, for example, an aryl group such as a phenyl group and a naphthyl group is preferable, and from the viewpoint of sublimability, a phenyl group having a low molecular weight is more preferable, and an aryl group such as a phenyl group having a substituent such as a methyl group, an isopropyl group, or a tert-butyl group is particularly preferable. From this viewpoint, halogen-substituted aryl groups are also preferable. The substituted halogen is preferably a fluorine atom.

The substituent is preferably introduced because when the organic compound is used in a method comprising dissolving the organic compound in a solvent, placing the resulting solution at a predetermined position or applying the resulting solution, and then removing the solvent, the properties of the resulting film are improved

Further, the substituent is preferably arranged so as to overlap with the pi-conjugated plane in plan view. Specifically, as shown in fig. 1, an o-tolyl compound having a methyl group at the ortho-position of the phenyl group and an o-biphenyl compound having a phenyl group at the ortho-position of the phenyl group are preferable because the substituent covers the pi conjugated plane of the basic skeleton and intermolecular stacking can be suppressed. Phenyl groups can effectively inhibit intermolecular stacking, compared to methyl groups. The plan view refers to a plan view when viewed from a direction perpendicular to the plane of the basic skeleton. Fig. 1 shows the structural formula of the molecule, a molecular plane direction 1 and a molecular plane direction 2. The structural formula of the molecule is the chemical structural formula of each compound. The molecular plane direction 1 shows a molecule when the structure represented by the structural formula is viewed from the left side of the page of fig. 1. The molecules are observed from a viewpoint parallel to the main face of the molecular structure. The molecular plane direction 2 shows a molecule when the structure represented by the structural formula is viewed from the lower side of the page of fig. 1. Observation from the planar direction of the molecule shows that the substituents are arranged at a large angle with respect to the plane of the molecule.

Therefore, when the organic compound according to the present embodiment satisfies the condition (v), an organic compound in which molecular stacking is suppressed and which has high sublimability is provided.

Table 4 shows exemplary compounds a3, C2, and D2 as compounds according to the present disclosure. Table 4 shows that the sublimation temperatures of C2 and D2 were reduced relative to the reduction in sublimation temperature of a 3. In C2 substituted by an o-tolyl group and D2 substituted by an o-biphenyl group, the groups cover the pi-conjugated plane, and the sublimation temperature is reduced relative to A3 in which the basic skeleton is substituted by a phenyl group. The sublimation temperature is 1.0 × 10^-2Sublimation initiation temperature when the compound is sublimated by raising the temperature under a vacuum of Pa or less. Note that the sublimation temperature of a3 is also reduced compared to the basic skeleton itself, and therefore the sublimability improves.

TABLE 4

As described above, since the organic compound according to the present embodiment has the above-described features (i) to (iii), an organic compound in which the emission wavelength of the basic skeleton itself is longer and the sublimability is maintained as compared with the comparative compound is provided. Further, when the organic compound according to the present embodiment has the above-described features (iv) and (v), a compound in which intermolecular stacking is suppressed and improvement in sublimability and suppression of concentration quenching can be achieved is provided. The use of the organic compound can provide an organic light-emitting element which has high efficiency and high element durability and which exhibits deep red light emission.

Specific examples of the organic compound according to the present embodiment are shown below. However, the present disclosure is not limited thereto.

Among the above-mentioned exemplified compounds, the exemplified compounds belonging to group a are examples in which the entire molecule is composed of hydrocarbons, and the basic skeleton has a phenyl group as a substituent. Here, a compound composed of hydrocarbons has a low HOMO energy level. Thus, compounds belonging to group a are compounds having a low oxidation potential, i.e. compounds which are stable to oxidation.

Therefore, among the compounds according to the present embodiment, organic compounds composed of hydrocarbons, that is, compounds belonging to group a, are preferable because of their high molecular stability. The compounds belonging to group a can be used as a host material, a transport layer or an injection layer of a light-emitting layer.

Among the above-mentioned exemplified compounds, exemplified compounds belonging to group B have a basic skeleton containing an aryl group with a substituent, a polycyclic aryl group, an aryl group with a heteroatom, or an amino group as a substituent. The substituent contained in the aryl group may be an alkyl group, a halogen atom such as a fluorine atom, a cyano group or an alkoxy group. In the compound having an alkyl group or fluorine, intermolecular stacking is suppressed. When these compounds are used as guest materials for the light-emitting layer, concentration quenching is suppressed. In addition, the exemplary compounds belonging to group B are compounds having high sublimability because the sublimation or vapor deposition initiation temperature is lowered, thereby increasing the difference between the temperature and the decomposition temperature. Further, the compound is useful as a material for coating because of its improved solubility.

The compound having an alkoxy group or an aryloxy group or a silyl group similarly has an effect of suppressing concentration quenching, and can be used as a material for coating. In the compound having a nitrogen-containing heterocyclic group or a cyano group, an electron withdrawing action is exerted on the basic skeleton. Thus, these compounds have a lower HOMO energy level and are more stable to oxidation than compounds belonging to group a. In the compound having an amino group, an electron donating effect is exerted on the basic skeleton. Therefore, these compounds have a narrow band gap and emit light having a longer wavelength. The compound containing an aryl group having 7 or more carbon atoms or a heterocyclic group has a higher glass transition temperature than the compound substituted with a phenyl group. Therefore, when these compounds are used as a host material or a transport layer of a light-emitting layer, a thermally stable amorphous film is formed.

Among the above-mentioned exemplified compounds, exemplified compounds belonging to group C are examples in which the basic skeleton is substituted with a phenyl group, and the phenyl group has a substituent at the ortho position thereof. The substituent may be an alkyl group, a halogen atom such as a fluorine atom, an alkoxy group and a cyano group. Since the phenyl group has a substituent at the ortho position thereof, the phenyl group is distorted with respect to the basic skeleton, and the ortho-position substituent covers the pi-conjugated plane of the basic skeleton to suppress molecular stacking. Since the exemplary compound belonging to group C has a substituent at the ortho position of the phenyl group, the exemplary compound belonging to group C is a compound that inhibits intermolecular stacking and has high sublimability, as compared to the exemplary compound belonging to group B. In addition, the use of an exemplary compound belonging to group C as a guest material of the light-emitting layer can suppress concentration quenching.

Among the above exemplified compounds, the exemplified compounds belonging to group D are examples in which the basic skeleton is substituted with a phenyl group, and the phenyl group further has a phenyl group at the ortho-position thereof. Since the effect of covering the pi-conjugated plane of the basic skeleton is higher than that of group C, the molecular stacking is further suppressed. Therefore, the example compound belonging to group D is a compound that inhibits intermolecular stacking and has high sublimability, as compared with the example compound belonging to group C.

Next, the organic light emitting element of the present embodiment will be described.

The organic light-emitting element of the present embodiment includes at least an anode and a cathode as a pair of electrodes, and an organic compound layer provided between the electrodes. In the organic light-emitting element of this embodiment mode, the organic compound layer may be formed of a single layer or a laminate including a plurality of layers as long as the organic compound layer includes a light-emitting layer.

When the organic compound layer is a stacked body including a plurality of layers, the organic compound layer may include, for example, a hole injection layer, a hole transport layer, an electron blocking layer, a charge generation layer, a hole/exciton blocking layer, an electron transport layer, and an electron injection layer, in addition to the light emitting layer. The light-emitting layer may be a single layer or a stacked body including a plurality of layers.

In the organic light-emitting element of this embodiment, at least one layer included in the organic compound layer contains the organic compound according to this embodiment. Specifically, the organic compound according to the present embodiment is contained in any one of a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole/exciton blocking layer, an electron transport layer, and a hole injection layer. The organic compound according to the present embodiment is preferably contained in the light-emitting layer.

When the organic compound according to the present embodiment is contained in the light-emitting layer of the organic light-emitting element of the present embodiment, the light-emitting layer may be a layer composed of the organic compound according to the present embodiment or a layer containing the organic compound according to the present embodiment and another compound. When the light emitting layer is a layer containing the organic compound according to the present embodiment and another compound, the organic compound according to the present embodiment may be used as a host of the light emitting layer or a guest of the light emitting layer. Alternatively, the organic compound according to the present embodiment may be used as an auxiliary material that may be included in the light-emitting layer.

The host is a compound having the highest weight ratio among compounds forming the light-emitting layer. The guest is a compound which is lower in weight ratio than the host and is responsible for main light emission, among compounds forming the light emitting layer. The auxiliary material is a compound that is lower in weight ratio than the host and assists the guest in emitting light, among compounds forming the light-emitting layer. The secondary material is also referred to as the second body. When it is assumed that the composition of the light emitting layer of the organic light emitting element is uniform, the composition of the entire light emitting layer can be determined by analyzing a part of the light emitting layer.

When the organic compound according to the present embodiment is used as a guest of the light-emitting layer, the concentration of the guest is preferably 0.01 wt% or more and 20 wt% or less, more preferably 0.1 wt% or more and 5 wt% or less, of the total weight of the light-emitting layer.

When the organic compound according to the present embodiment is used as a guest of a light emitting layer, a material having a higher LUMO level (a material having a LUMO closer to a vacuum level) than the organic compound according to the present embodiment may be used as a host. This is because the organic compound according to the present embodiment has a low LUMO level, and thus using a compound having a higher LUMO level as compared to the organic compound of the present embodiment as a host enables the organic compound according to the present embodiment to receive a larger portion of electrons supplied to the host of the light emitting layer.

As a result of various studies, the inventors of the present disclosure found that using the organic compound according to the present embodiment as a host or a guest, particularly a guest as a light emitting layer, provides an element that produces light output with high efficiency and high luminance and has extremely high durability. The light emitting layer may be formed of a single layer, or may have a multi-layer structure. The light emitting layer may contain other light emitting materials having still other light emitting colors to emit color light mixed with red (light emitting color of the present embodiment). The multilayer structure refers to a state in which a light emitting layer is stacked with another light emitting layer. In this case, the light emission color of the organic light emitting element is not limited to red. More specifically, the emission color may be white or an intermediate color. When the light emission color is white, the other light emitting layers emit light of a color other than red, for example, blue or green. The light emitting layer is formed by a method such as vapor deposition or coating. Details of the method will be described more specifically in the following examples.

The organic compound according to this embodiment can be used as a material for forming an organic compound layer other than the light-emitting layer included in the organic light-emitting element of this embodiment. Specifically, the organic compound according to the present embodiment can be used as a material for forming an electron transport layer, an electron injection layer, a hole transport layer, a hole injection layer, a hole blocking layer, or the like. In this case, the light emission color of the organic light emitting element is not limited to red. More specifically, the emission color may be white or an intermediate color.

Here, the organic compound according to the present embodiment may be used in combination with a known low-molecular-weight or high-molecular-weight hole injecting compound or hole transporting compound, a compound serving as a host, a light emitting compound, an electron injecting compound, an electron transporting compound, and the like, as necessary.

Examples of these compounds will be described below. The hole injecting or transporting material is preferably a material having high hole mobility so as to facilitate hole injection from the anode and enable the injected holes to be transported to the light-emitting layer. From the viewpoint of suppressing deterioration in film quality such as crystallization in an organic light-emitting element, a material having a high glass transition temperature is preferable. Examples of low or high molecular weight materials having hole injection or transport properties include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly (vinylcarbazole), poly (thiophene), and other conductive polymers. The hole injecting or transporting material described above is also suitable for use as an electron blocking layer.

Specific examples of the compound used as the hole injecting or transporting material are shown below, but not limited thereto.

Examples of the light-emitting material mainly relating to a light-emitting function include condensed ring compounds (such as fluorene derivatives, naphthalene derivatives, pyrene derivatives, perylene derivatives, tetracene derivatives, anthracene derivatives, and rubrene), quinacridone derivatives, coumarin derivatives, stilbene derivatives, organic aluminum complexes such as tris (8-hydroxyquinoline) aluminum, iridium complexes, platinum complexes, rhenium complexes, copper complexes, europium complexes, ruthenium complexes, and high molecular derivatives such as poly (phenylenevinylene) derivatives, poly (fluorene) derivatives, and poly (phenylene) derivatives, in addition to the organic compounds represented by the general formula (1).

The organic compound according to the present embodiment is a compound having a narrow band gap and a low HOMO/LUMO level. Therefore, when a mixed layer is formed with other light emitting materials or a light emitting layer is stacked, similarly, the other light emitting materials also preferably have a low HOMO/LUMO energy level. This is because when the other light emitting material has a high HOMO/LUMO level, a quenching component or trap level (trap level) may be formed, and for example, the other light emitting material may form an excited state complex together with the organic compound according to the present embodiment.

Specific examples of the compound used as the light-emitting material are shown below, but not limited thereto.

Examples of the light-emitting layer host or the light-emitting auxiliary material contained in the light-emitting layer include carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organoaluminum complexes such as tris (8-hydroxyquinoline) aluminum, and organoberyllium complexes, in addition to the aromatic hydrocarbon compound and its derivatives.

The organic compound according to the present embodiment is a compound having a narrow band gap and a low HOMO/LUMO level. Thus, preferably, the host material is also formed of a hydrocarbon and similarly has a low HOMO/LUMO energy level. This is because when the host material contains a heteroatom such as a nitrogen atom, the HOMO/LUMO level becomes high and a quenching component or a trap level may be formed, and for example, the host material may form an excited state complex together with the organic compound according to the present embodiment.

The host material particularly preferably has an anthracene, tetracene, perylene, or pyrene skeleton in its molecular skeleton. This is because such a compound is composed of hydrocarbons as described above and has S1 energy that enables sufficient energy transfer of the organic compound of the present embodiment.

Specific examples of the compound used as a host or an emission auxiliary material of the emission layer included in the emission layer are shown below, but are not limited thereto.

The electron transporting material can be freely selected from materials capable of transporting electrons injected from the cathode to the light emitting layer, and is selected in consideration of, for example, a balance with the hole mobility of the hole transporting material. Examples of the material having an electron transporting property include oxadiazole derivatives, oxazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, organoaluminum complexes, and fused ring compounds (e.g., fluorene derivatives, naphthalene derivatives, metal halide,

Derivatives and anthracene derivatives). The above-mentioned electron-transporting material is also suitable as a hole-blocking layer.

Specific examples of the compound used as the electron transporting material are shown below, but not limited thereto.

Structure of organic light emitting element

An organic light-emitting element is obtained by providing an anode, an organic compound layer, and a cathode on a substrate. For example, the overcoat layer and the color filter may be disposed on the cathode. In the case where the color filter is provided, the planarization layer may be formed in advance.

Examples of the substrate include quartz, glass, silicon wafers, resins, and metals. The substrate includes a switching element such as a transistor and a wiring thereon, and may further include an insulating layer thereon. The material of the insulating layer is not limited as long as a contact hole can be formed to establish electrical connection between the anode and the wire and insulation from the unconnected wire can be achieved. Examples of the material of the insulating layer include resin such as polyimide, silicon oxide, and silicon nitride.

The anode material preferably has a work function as high as possible. Examples of the anode material include elemental metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten; mixtures containing these metals; alloys of these metals; and metal oxides such as tin oxide, zinc oxide, Indium Tin Oxide (ITO), and indium zinc oxide. Examples thereof further include conductive polymers such as polyaniline, polypyrrole, and polythiophene.

These electrode materials may be used alone or in combination of two or more. The anode may be formed of a single layer or multiple layers.

When the anode is used as the reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, an alloy thereof, or a laminate thereof can be used. When the anode is used as the transparent electrode, a transparent conductive oxide layer made of, for example, Indium Tin Oxide (ITO) or indium zinc oxide may be used, but the transparent electrode is not limited thereto. Photolithography may be used to form the electrodes.

In contrast, the cathode material preferably has a low work function. Examples of the cathode material include alkali metals such as lithium; alkaline earth metals such as calcium; elemental metals such as aluminum, titanium, manganese, silver, lead, and chromium; and mixtures containing these metals. Alloys of these elemental metals may also be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, and zinc-silver may be used. For example, a metal oxide such as Indium Tin Oxide (ITO) may be used. These electrode materials may be used alone or in combination of two or more. The cathode may be formed of a single layer or multiple layers.

The form of the cathode is not particularly limited. The cathode may be a conductive oxide layer made of ITO or the like to provide a top light emitting element. Alternatively, the cathode may be a reflective electrode made of aluminum (Al) or the like to provide a bottom light emitting element. The method of forming the cathode is not particularly limited. For example, DC and AC sputtering methods can be used because good film coverage is achieved to easily reduce the resistance.

After the cathode is formed, a sealing member (not shown) may be provided. For example, a glass plate provided with a moisture absorbent may be bonded to the cathode. Therefore, it is possible to suppress the penetration of water or the like in the organic EL layer, thereby suppressing the occurrence of display defects. In another embodiment, a passivation film made of silicon nitride or the like may be provided on the cathode to suppress permeation of water or the like in the organic EL layer. For example, after the cathode formation, the resultant substrate may be transferred to another chamber without breaking vacuum, and a silicon nitride film having a thickness of 2 μm is formed by a CVD method to provide a protective layer.

A color filter may be disposed on each pixel. For example, color filters each having a size corresponding to the pixel size may be formed on another substrate, and the substrate may be adhered to a substrate having organic EL elements thereon. Alternatively, the color filter may be formed by forming a pattern on a sealing film made of silicon oxide or the like using a photolithography method.

The organic compound layer (for example, a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer) forming the organic light emitting element according to the present embodiment is formed by the following method.

The organic compound layer forming the organic light-emitting element according to the present embodiment can be formed by using a dry method such as a vacuum vapor deposition method, an ionization vapor deposition method, a sputtering method, or plasma. Alternatively, instead of the dry method, a wet method in which an organic compound is dissolved in a suitable solvent and a layer is formed by a known coating method (e.g., spin coating, dipping, a casting method, a Langmuir-blodgett (lb) method, or an inkjet method) may also be employed.

When the layer is formed by, for example, a vacuum vapor deposition method or a solution coating method, crystallization is less likely to occur, and the resulting layer has good stability with time. When the layer is formed by a coating method, the layer may be formed by using a suitable binder resin in combination.

Examples of the binder resin include, but are not limited to, polyvinylcarbazole resins, polycarbonate resins, polyester resins, ABS resins, acrylic resins, polyimide resins, phenol resins, epoxy resins, silicone resins, and urea resins.

These binder resins may be used alone as a homopolymer or a copolymer, or in combination as a mixture of two or more. In addition, known additives such as a plasticizer, an oxidation inhibitor, and an ultraviolet absorber may be optionally used in combination.

Application of the organic light-emitting element of this embodiment mode

The organic light-emitting element according to the present embodiment can be used as a member of a display device or a lighting device. In addition, the organic light-emitting element can be used, for example, as an exposure light source of an electrophotographic image forming apparatus, a backlight of a liquid crystal display apparatus, or a light-emitting apparatus including a white light source having a filter.

The display device may be an image information processing device including an image input unit that inputs image information from an area CCD, a line CCD, a memory card, or the like, and an information processing unit that processes the input information and displays the input image on the display unit.

The display unit included in the image forming apparatus or the inkjet printer may have a touch panel function. The touch panel function can be operated by using infrared rays, electrostatic capacitance, resistive film, or electromagnetic induction, and the operation method is not particularly limited. The display device may be used as a display unit of a multifunction printer.

Next, a display device according to the present embodiment will be described with reference to the drawings. Fig. 2 is a schematic cross-sectional view showing an example of a display device including an organic light-emitting element and a TFT element connected to the organic light-emitting element. TFT elements are examples of active elements.

The display device 10 in fig. 2 includes a substrate 11 made of, for example, glass, and a moisture-proof film 12 that is provided on the substrate 11 and protects TFT elements or an organic compound layer. A metal gate electrode 13, a gate insulating film 14, and a semiconductor layer 15 are provided.

The TFT element 18 includes a semiconductor layer 15, a drain electrode 16, and a source electrode 17. An insulating film 19 is provided on the TFT element 18. The anode 21 forming the organic light emitting element 26 and the source electrode 17 are connected to each other through the contact hole 20.

The form of electrical connection between the electrodes (anode and cathode) included in the organic light-emitting element and the electrodes (source and drain electrodes) included in the TFT is not limited to the form shown in fig. 2. Specifically, the anode or the cathode is electrically connected to the source electrode or the drain electrode of the TFT element.

In the display device 10 in fig. 2, the organic compound layer 22 is shown as if the organic compound layer 22 is formed of a single layer. Alternatively, the organic compound layer 22 may be formed of a plurality of layers. A first protective layer 24 and a second protective layer 25 that suppress deterioration of the organic light-emitting element 26 are provided on the cathode 23.

In the display device 10 in fig. 2, a transistor is used as a switching element. Alternatively, a MIM element may be used as the switching element instead of the transistor.

The transistor used in the display device 10 in fig. 2 is not limited to a transistor using a single crystal silicon wafer. Alternatively, the transistor may be a thin film transistor having an active layer on an insulating surface of a substrate. Examples of the active layer include single crystal silicon, amorphous silicon, non-single crystal silicon such as microcrystalline silicon, and non-single crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. The thin film transistor is also referred to as a TFT element.

The transistors included in the display device 10 in fig. 2 may be formed in a substrate such as a Si substrate. Here, the expression "formed in a substrate" refers to manufacturing a transistor by processing a substrate such as a Si substrate itself. That is, having a transistor in a substrate may also be considered to be that the substrate and the transistor are integrally formed.

Whether or not to dispose the transistor in the substrate is selected according to the resolution level. For example, with a size of 1 inch and a resolution of about QVGA, the transistors may be disposed in a Si substrate.

Fig. 3 is a schematic diagram showing an example of a display device according to the present embodiment. The display apparatus 1000 includes an upper cover 1001, a lower cover 1009, and a touch panel 1003, a display panel 1005, a frame 1006, a printed circuit board 1007, and a battery 1008 provided between the upper cover 1001 and the lower cover 1009. The touch panel 1003 and the display panel 1005 are connected to Flexible Printed Circuits (FPCs) 1002 and 1004, respectively. The transistors are printed on a printed circuit board 1007. The battery 1008 need not be provided unless the display device is a mobile device. Even when the display device is a mobile device, the battery 1008 is not necessarily provided at the position shown in the drawing.

The display device according to the present embodiment can be used as a display unit of an imaging device including an optical unit having a plurality of lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may include a display unit that displays information obtained by the imaging element. The display unit may be a display unit exposed to the outside of the imaging device or a display unit provided in the viewfinder. The imaging device may be a digital camera or a digital camcorder.

Fig. 4A is a schematic diagram showing an example of the imaging apparatus according to the present embodiment. The imaging apparatus 1100 includes a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may include the display device according to the present embodiment. In this case, the display device can display not only an image to be captured but also, for example, environmental information and imaging instructions. The environmental information may include, for example, the intensity of external light, the direction of the external light, the moving speed of the subject to be captured, and the possibility of the subject being blocked by an object.

Since the appropriate time to take an image is a very short period of time, it is desirable to display the information as quickly as possible. Therefore, a display device including the organic light emitting element according to the present disclosure is preferably used. This is because the organic light emitting element has a high response speed. A display device including the organic light emitting element is more suitable than a liquid crystal display device for a device requiring a high display speed.

The imaging apparatus 1100 includes an optical unit (not shown). The optical unit has a plurality of lenses and forms an image on an imaging element provided in the housing 1104. The focus can be adjusted by adjusting the relative positions of the plurality of lenses. This operation may be automated.

The display device according to the present embodiment may include red, green, and blue color filters. The red, green and blue color filters may be arranged in a triangular array.

The display device according to the present embodiment may be used in a display unit of a mobile terminal. In this case, the display unit may have both the display function and the operation function. Examples of mobile terminals include mobile phones, such as smart phones, tablets, and head mounted displays.

Fig. 4B is a schematic diagram showing an example of an electronic device according to the present embodiment. The electronic device 1200 includes a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may include therein an electric circuit, a printed board having the electric circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel response unit. The operation unit 1202 may be a biometric authentication unit configured to recognize a fingerprint and unlock, for example. An electronic device including a communication unit may be referred to as a communication device.

Fig. 5A and 5B are schematic diagrams each showing an example of a display device according to the present embodiment. Fig. 5A shows a display device such as a television display screen or a Personal Computer (PC) display screen. The display apparatus 1300 includes a frame 1301 and a display unit 1302. The display unit 1302 may include a light emitting element according to the present embodiment.

The display apparatus 1300 further includes a base 1303 which supports the frame 1301 and the display unit 1302. The base 1303 is not limited to the form shown in fig. 5A. Alternatively, the underside of the frame 1301 may also serve as a base.

The frame 1301 and the display unit 1302 may be curved. The radius of curvature may be in the range of 5,000mm or more and 6000mm or less.

Fig. 5B is a schematic diagram showing another example of the display device according to the present embodiment. The display device 1310 shown in fig. 5B is configured to be foldable and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a folding point 1314. The first display unit 1311 and the second display unit 1312 may each include a light emitting element according to this embodiment mode. The first display unit 1311 and the second display unit 1312 may be a single display device without being joined. The first display unit 1311 and the second display unit 1312 may be separated from each other at a folding point 1314. The first display unit 1311 and the second display unit 1312 may display images different from each other. Alternatively, one image may be displayed on one set of the first display unit 1311 and the second display unit 1312.

Fig. 6A is a schematic view showing an example of the lighting device according to the present embodiment. The lighting device 1400 includes a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusion unit 1405. The light source 1402 may include an organic light emitting element according to the present embodiment. Optical film 1404 may be a film that improves color rendering of light source 1402. The light diffusion unit 1405 effectively diffuses light emitted from the light source 1402 and allows the light to reach a wide area, for example, for illumination. The optical film 1404 and the light diffusion unit 1405 may be disposed on the light emitting side of the illumination. A cover may optionally be provided on the outermost portion.

The lighting device is, for example, a device for illuminating a room. The lighting device may emit light of white, natural white or any other color from blue to red. The illumination device may include a light modulation circuit configured to modulate light. The lighting device may include an organic light emitting element according to the present disclosure and a power supply circuit connected to the organic light emitting element. The power supply circuit is a circuit configured to convert an alternating-current voltage into a direct-current voltage. The color temperature of white was 4,200K, and the color temperature of natural white was 5,000K. The illumination device may include a color filter.

The lighting device according to the present embodiment may include a heat dissipation unit. The heat dissipating unit dissipates heat in the device to the outside of the device, and may be made of, for example, metal having high specific heat or liquid silicon.

Fig. 6B is a schematic diagram of an automobile as an example of the moving body according to the present embodiment. Automobiles include rear lights as an example of lighting fixtures. The car 1500 comprises a tail light 1501, and the tail light 1501 may be illuminated when, for example, a brake is applied.

The tail light 1501 may include the organic light emitting element according to the present embodiment. The tail light 1501 may include a protective member that protects the organic light emitting element. The protective member may be made of any material as long as the strength of the protective member is high to some extent and the protective member is transparent. The protective member may be made of polycarbonate or the like. The polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

The automobile 1500 may include a body 1503 and a window 1502 attached to the body 1503. Unless the window is a window for inspecting the front and rear of the car, the window may be a transparent display. The transparent display may include the organic light emitting element according to the present embodiment. In this case, members such as electrodes of the organic light emitting element are made of a transparent material.

The mobile body according to the present embodiment may be a ship, an airplane, an unmanned aerial vehicle, or the like. The moving body may include a main body and a lighting fixture disposed on the main body. The lighting fixture may illuminate to indicate the location of the subject. The lighting fixture includes the organic light emitting element according to the present embodiment.

In the organic light emitting element according to the present embodiment, light emission luminance is controlled by a TFT as an example of a switching element. Therefore, when a plurality of such organic light emitting elements are arranged in a plane, an image can be displayed by controlling the light emission luminance of each organic light emitting element. The switching element according to this embodiment is not limited to the TFT. The switching elements may be transistors formed of low temperature polysilicon or active matrix drivers formed on or in a substrate, such as a Si substrate. Whether on or in the substrate is selected according to the resolution level. For example, in the case of a size of 1 inch and a resolution of about QVGA, the organic light emitting element may be disposed on the Si substrate. By driving the display device including the organic light emitting element according to the present embodiment, an image with good image quality can be stably displayed for a long time.