Organic compound, organic light emitting diode and organic light emitting device containing the same
阅读说明:本技术 有机化合物、含有该化合物的有机发光二极管和有机发光装置 (Organic compound, organic light emitting diode and organic light emitting device containing the same ) 是由 裵淑英 申仁爱 金捘演 于 2019-08-02 设计创作,主要内容包括:公开了具有螺-蒽核和与所述核结合的芳族或杂芳族基团和/或氨基的有机化合物,以及包含所述有机化合物的有机发光二极管和有机发光装置。由于本公开的有机化合物具有刚性结构和很窄的半峰全宽(FWHM),故可以使用所述有机化合物制造驱动电压降低且发光效率和色纯度增强的有机发光二极管和有机发光装置。(Disclosed are organic compounds having a spiro-anthracene core and an aromatic or heteroaromatic group and/or an amino group bound to the core, and organic light emitting diodes and organic light emitting devices comprising the same. Since the organic compound of the present disclosure has a rigid structure and a narrow full width at half maximum (FWHM), an organic light emitting diode and an organic light emitting device, in which a driving voltage is reduced and luminous efficiency and color purity are enhanced, may be manufactured using the organic compound.)
1. An organic compound represented by the following chemical formula 1:
chemical formula 1
Wherein R is1And R2Each independently selected from the group consisting of: hydrogen, deuterium, tritium, unsubstituted or substituted by C4~C30Amino of an aromatic or heteroaromatic radical, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaryl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aralkyl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaralkyl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryloxy group, and unsubstituted or substituted with C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaryloxy, and R1And R2Is not hydrogen, deuterium and tritium,
wherein L is1And L2Each independently selected from the group consisting of: unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Arylene, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroarylene radical, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aralkylene, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroarylene radical, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryloxy ene group, and unsubstituted or substituted with C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroarylene group, and m and n are each independently 0 (zero) or 1, and
wherein X is CR3R4、NR5O or S, R3To R5Each independently selected from the group consisting of: hydrogen, straight or branched C1~C20Alkyl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaryl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aralkyl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaralkyl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryloxy radical, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaryloxy, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Arylamino, and unsubstituted or substituted with C4~C30C of aromatic or heteroaromatic radicals4~C30A heteroarylamino group.
2. The organic compound of claim 1, wherein the organic compound has a structure of the following chemical formula 2:
chemical formula 2
Wherein R is11And R12Each independently selected from the group consisting of substituted or unsubstituted4~C30C of aromatic or heteroaromatic radicals5~C30Aryl and unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaryl, and L3And L4Each independently selected from the group consisting of substituted or unsubstituted4~C30C of aromatic or heteroaromatic radicals5~C30Arylene, and unsubstituted or substituted with C4~C30C of aromatic or heteroaromatic radicals4~C30A group consisting of heteroarylene groups,
wherein o and p are each independently 0 (zero) or 1, and at least one of o and p is 1, and
wherein m, n and X are each the same as defined in chemical formula 1.
3. The organic compound of claim 1, wherein the organic compound has a structure of the following chemical formula 3:
chemical formula 3
Wherein R is21To R24Each independently selected from the group consisting of: unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryl, and unsubstituted or substituted with C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaryl, and o and p are each independently 0 (zero) or 1, and
wherein at least one of o and p is 1, and X is the same as defined in chemical formula 1.
4. The organic compound of claim 1, wherein the organic compound has one of the structures of the following chemical formula 4:
chemical formula 4
5. An organic light emitting diode, comprising:
a first electrode;
a second electrode facing the first electrode; and
a first layer of emissive material between the first and second electrodes,
wherein the first emissive material layer comprises the organic compound of claim 1.
6. The organic light emitting diode of claim 5, wherein the first emissive material layer further comprises a first host, wherein the organic compound serves as a first fluorescent dopant.
7. The organic light emitting diode of claim 5, wherein the first emission material layer further comprises a first host and a first dopant, wherein the organic compound serves as a second dopant.
8. The organic light-emitting diode of claim 7, wherein the excited singlet energy level of the first dopant is higher than the excited singlet energy level of the second dopant.
9. The organic light-emitting diode of claim 7, wherein an energy band gap between an excited singlet state level of the first dopant and an excited triplet state level of the first dopant is equal to or less than about 0.3 eV.
10. The organic light emitting diode of claim 7, an energy band gap between a highest occupied molecular orbital level of the first body and a highest occupied molecular orbital level of the first dopant or an energy band gap between a lowest unoccupied molecular orbital level of the first body and a lowest unoccupied molecular orbital level of the first dopant being equal to or less than about 0.5 eV.
11. The organic light-emitting diode of claim 7, wherein the excited triplet level of the first dopant is lower than the excited triplet level of the first host and higher than the excited triplet level of the second dopant.
12. The organic light emitting diode of claim 6, further comprising: a second emitting material layer between the first electrode and the first emitting material layer or between the first emitting material layer and the second electrode, wherein the second emitting material layer includes a second host and a delayed fluorescence dopant.
13. The organic light emitting diode of claim 12, wherein the second emissive material layer is disposed between the first emissive material layer and the second electrode, and further comprising an electron blocking layer between the first electrode and the first emissive material layer.
14. The organic light emitting diode of claim 13, wherein the first host is the same material as the electron blocking layer.
15. The organic light emitting diode of claim 12, wherein the second emissive material layer is disposed between the first electrode and the first emissive material layer, and further comprising a hole blocking layer between the first emissive material layer and the second electrode.
16. The organic light emitting diode of claim 15, wherein the first host is the same material as the hole blocking layer.
17. The organic light-emitting diode of claim 12, wherein the delayed fluorescent dopant has an excited singlet energy level higher than an excited singlet energy level of the first fluorescent dopant.
18. The organic light-emitting diode of claim 12, wherein the excited singlet energy level of the first host is higher than the excited singlet energy level of the first fluorescent dopant, and the excited singlet energy level and the excited triplet energy level of the second host are each higher than the excited singlet energy level and the excited triplet energy level of the delayed fluorescent dopant, respectively.
19. The organic light emitting diode of claim 12, further comprising a third emissive material layer disposed opposite the first emissive material layer relative to the second emissive material layer, wherein the third emissive material layer comprises a third host and a second fluorescent dopant.
20. The organic light emitting diode of claim 19, wherein the second emissive material layer is disposed between the first emissive material layer and the second electrode, the third emissive material layer is disposed between the second emissive material layer and the second electrode, and the organic light emitting diode further comprises an electron blocking layer between the first electrode and the first emissive material layer.
21. The organic light emitting diode of claim 20, wherein the first host is the same material as the electron blocking layer.
22. The organic light emitting diode of claim 19, wherein the second emissive material layer is disposed between the first emissive material layer and the second electrode, the third emissive material layer is disposed between the second emissive material layer and the second electrode, and the organic light emitting diode further comprises a hole blocking layer between the third emissive material layer and the second electrode.
23. The organic light emitting diode of claim 20, wherein the third body is the same material as the hole blocking layer.
24. The organic light-emitting diode of claim 19, wherein the delayed fluorescent dopant has an excited singlet energy level higher than the excited singlet energy level of the first fluorescent dopant and the excited singlet energy level of the second fluorescent dopant.
25. The organic light-emitting diode of claim 19, wherein the first host has an excited singlet energy level that is higher than an excited singlet energy level of the first fluorescent dopant, wherein the second host has an excited singlet energy level and an excited triplet energy level that are each higher than an excited singlet energy level and an excited triplet energy level of the delayed fluorescent dopant, respectively, and wherein the third host has an excited singlet energy level that is higher than an excited singlet energy level of the second fluorescent dopant.
26. An organic light-emitting device, comprising:
a substrate; and
an organic light emitting diode according to claim 5 on said substrate.
Technical Field
The present disclosure relates to an organic compound, and more particularly, to an organic compound that enhances luminous efficiency and color purity, an organic light emitting diode and an organic light emitting device including the same.
Background
As display devices become larger, flat display devices that occupy less space are required. Among the flat display devices, a display device using an Organic Light Emitting Diode (OLED) has been a focus of attention.
In the OLED, when charges are injected into an emission layer between an electron injection electrode (i.e., a cathode) and a hole injection electrode (i.e., an anode), the charges are combined into a pair and then light is emitted when the combined charges disappear.
The OLED may even be formed on a flexible transparent substrate, such as a plastic substrate. In addition, the OLED can be driven at a lower voltage of 10V or less. In addition, the OLED has relatively low driving power consumption and very high color purity, compared to the plasma display panel and the inorganic electroluminescent device. In addition, since the OLED can display various colors such as green, blue, and red, the OLED display device attracts much attention as a next generation display device that can replace a liquid crystal display device (LCD).
An OLED may have a single layer of emissive material between an anode and a cathode. Alternatively, the OLED may have a multi-layer emission layer including a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), an Emission Material Layer (EML), an Electron Transport Layer (ETL), and an Electron Injection Layer (EIL) between an anode and a cathode, so that the OLED may enhance light emitting efficiency. The multilayer emission layer may further include an exciton blocking layer, such as an Electron Blocking Layer (EBL) between the HTL and the EML and/or a Hole Blocking Layer (HBL) between the EML and the ETL, in order to prevent excitons from disappearing.
The EML generally includes a host and a dopant, and the actual emission is performed at the dopant. Since a material used as a blue dopant must have a wider band gap than green and/or red dopants, there is a difficulty in developing a blue dopant. U.S. patent application No.2007/0292714 discloses a blue light emitting material having a pyrene nucleus and a diphenylamino substituent. However, the prior art light emitting material has low light emitting efficiency, short lifetime, low color purity, and is limited in realizing full color display.
Disclosure of Invention
Accordingly, the present disclosure is directed to organic compounds, organic light emitting diodes and organic light emitting devices including the same that substantially obviate one or more problems due to limitations and disadvantages of the related art.
An object of the present disclosure is to provide an organic compound, an organic light emitting diode, and an organic light emitting device that can enhance light emitting efficiency and color purity.
Another object of the present disclosure is to provide an organic light emitting diode and an organic light emitting device that can reduce driving voltage and power consumption and can improve lifespan.
Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the disclosure. The objectives and other advantages of the disclosure will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
According to one aspect, the present disclosure provides an organic compound represented by the following chemical formula 1:
Wherein R is1And R2Each independently selected from the group consisting of: hydrogen, unsubstituted or substituted by C4~C30Amino of an aromatic or heteroaromatic radical, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaryl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aralkyl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaralkyl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryloxy group, and unsubstituted or substituted with C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaryloxy, and R1And R2Is not hydrogen, deuterium and tritium; l is1And L2Each independently selected from the group consisting of: unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Arylene, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroarylene, unsubstituted or substitutedHas C4~C30C of aromatic or heteroaromatic radicals5~C30Aralkylene, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroarylene radical, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryloxy ene group, and unsubstituted or substituted with C4~C30C of aromatic or heteroaromatic radicals4~C30A heteroarylene group; m and n are each independently 0 (zero) or 1; x is CR3R4、NR5O or S, wherein R3To R5Each independently selected from the group consisting of: hydrogen, straight or branched C1~C20Alkyl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaryl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aralkyl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaralkyl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryloxy radical, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaryloxy, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Arylamino, and unsubstituted or substituted with C4~C30C of aromatic or heteroaromatic radicals4~C30A heteroarylamino group.
According to another aspect, the present disclosure provides an Organic Light Emitting Diode (OLED) including: a first electrode; a second electrode facing the first electrode; and a first emission material layer between the first electrode and the second electrode, wherein the first emission material layer contains the above-described organic compound.
According to yet another aspect, the present disclosure provides an organic light emitting device including: substrate: and an OLED as described above disposed on the substrate.
It is to be understood that both the foregoing general description and the following detailed description are examples, and are intended to provide further explanation of the disclosure as claimed.
Drawings
The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the principles of various embodiments of the disclosure.
Fig. 1 is a schematic cross-sectional view illustrating an organic light emitting display device of the present disclosure;
fig. 2 is a schematic cross-sectional view illustrating an organic light emitting diode according to an exemplary embodiment of the present disclosure;
fig. 3 is a schematic view illustrating a light emission mechanism of an energy band gap between a host and an organic compound as a fluorescent dopant in a single-layer EML according to an exemplary embodiment of the present disclosure;
fig. 4 is a schematic cross-sectional view illustrating an organic light emitting diode according to another exemplary embodiment of the present disclosure;
fig. 5 is a schematic view illustrating a light emitting mechanism of a delayed fluorescent material according to another exemplary embodiment of the present disclosure;
fig. 6 is a schematic view illustrating a light emitting mechanism by an energy level band gap between a host, a fluorescent dopant and a delayed fluorescent dopant in a single-layer EML according to another exemplary embodiment of the present disclosure;
fig. 7 is a schematic cross-sectional view illustrating an organic light emitting diode according to another exemplary embodiment of the present disclosure;
fig. 8 is a schematic cross-sectional view illustrating an organic light emitting diode according to another exemplary embodiment of the present disclosure;
fig. 9 is a schematic view illustrating a light emitting mechanism by an energy level band gap between a host, a delayed fluorescence dopant, and a fluorescent material in a dual-layer EML according to another exemplary embodiment of the present disclosure;
fig. 10 is a schematic cross-sectional view illustrating an organic light emitting diode according to another exemplary embodiment of the present disclosure;
fig. 11 is a schematic view illustrating a light emitting mechanism by an energy level band gap between a host, a delayed fluorescence dopant, and a fluorescent material in a three-layered EML according to another exemplary embodiment of the present disclosure.
Detailed Description
Reference will now be made in detail to aspects of the present disclosure, examples of which are illustrated in the accompanying drawings.
Organic compounds
When holes injected from the anode and electrons injected from the cathode are combined in the EML to form excitons, the Organic Light Emitting Diode (OLED) emits light, and then the unstable excited-state excitons return to the stable ground state. The external quantum efficiency of the luminescent material applied in the EML can be calculated by the following equation (1):
ηext=ηS/T×г×Φ×ηlight emission(1)
In equation (1), "ηS/T"is the exciton generation efficiency (singlet/triplet ratio)," г "is the charge balance factor,". phi "is the radiative quantum efficiency,". ηLight emission"is the light extraction efficiency.
“ηS/T"is the conversion ratio from exciton to light, with a maximum of 0.25 in the case of fluorescent materials. Theoretically, when an electron encounters a hole to form an exciton, a singlet exciton of a paired spin and a triplet exciton of an unpaired spin are generated in a ratio of 1:3 by spin alignment. In the case of fluorescent materials, only singlet excitons among the excitons can participate in the emission process.
The charge balance factor "г" is the balance between holes and electrons (both forming excitons), and is typically a value of "1", assuming a 1:1 match of 100%, "Φ" is a value that is related to the luminous efficiency of the actual light-emitting material, and depends on the photoluminescence of the dopants in the host-dopant system.
“ηLight emission"is the ratio of light extracted outwards of the light emitted within the luminescent material. When the isotropic luminescent material is thermally deposited to form a thin film, each luminescent molecule does not have a specific orientation but exists in a random state. The light extraction efficiency of such random orientation is generally assumed to be "0.2". Therefore, when the 4 parameters of the above equation (1) are combined, the OLED can show a maximum luminous efficiency of 5% in the case of using the related art fluorescent material.
In contrast, phosphorescent materials use different light emission mechanisms that convert singlet and triplet excitons into light. Phosphorescent materials convert singlet excitons into triplet excitons through intersystem crossing (ISC). Therefore, in the case of applying a phosphorescent material using both singlet excitons and triplet excitons in light emission, the light emission efficiency can be improved as compared to a fluorescent material.
In the case of using a metal complex having a heavy metal such as Ir and Pt as a phosphorescent material, the triplet state can be converted into the singlet state by the strong spin-orbit bond of the heavy metal. However, the prior art blue phosphorescent material has not been used in commercial display devices because it does not have sufficient color purity for display devices and exhibits very short emission lifetime.
Therefore, there is a need to develop a light emitting compound having enhanced luminous efficiency and color purity, and a light emitting diode including the same. The organic compounds of the present disclosure comprise a spiro-anthracene nucleus having a rigid chemical conformation, and at least one substituent bound to the spiro-anthracene nucleus. The organic compound of the present disclosure may be represented by the following chemical formula 1:
In
L1and L2Each independently selected from the group consisting of: unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Arylene, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroarylene radical, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aralkylene, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroarylene radical, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryloxy ene group, and unsubstituted or substituted with C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroarylene group, and m and n are each independently 0 (zero) or 1, and
x is CR3R4、NR5O or S. R3To R5Each independently selected from the group consisting of: hydrogen, deuterium, tritium, straight or branched C1~C20Alkyl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaryl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aralkyl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaralkyl, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryloxy radical, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals4~C30Heteroaryloxy, unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Arylamino, and unsubstituted or substituted with C4~C30C of aromatic or heteroaromatic radicals4~C30A heteroarylamino group.
As used herein, the term "having no substituents" means that hydrogen atoms are bonded, and the hydrogen atoms in this case include protium, deuterium, and tritium.
As used herein, the term "hetero" described in "heteroaromatic ring", "heteroaromatic group", "heteroalicyclic ring", "heterocycloaikyi", "heteroaryl", "heteroaralkyl", "heteroaryloxy", "heteroarylamino", "heteroarylene", and "heteroarylene oxy" and the like means that at least one carbon atom (e.g., 1 to 5 carbon atoms) forming such aromatic or alicyclic ring is substituted with at least one heteroatom selected from the group consisting of N, O, S and combinations thereof.
Can be at R1、R2、R3、R4And/or R5Amino group of (1), C5~C30Aryl radical, C4~C30Heteroaryl group, C5~C30Aralkyl radical, C4~C30Heteroaralkyl radical, C5~C30Aryloxy radical, C4~C30Heteroaryloxy radical, C5~C30Arylene radical, C5~C30Arylamino and C4~C30At least one of heteroarylamino and/or L1And/or L2C of (A)5~C30Arylene radical, C4~C30Heteroarylene radical, C5~C30Aralkylene, C4~C30Heteroarylene radical, C5~C30Arylene group and C4~C30C substituted on at least one heteroarylene group4~C30The aromatic or heteroaromatic group may be unsubstituted or substituted with at least one other functional group. E.g. C4~C30The aromatic or heteroaromatic group may be substituted with, but is not limited to: c unsubstituted or substituted by halogen atoms, cyano groups and/or nitro groups1~C20An alkyl group; c unsubstituted or substituted by cyano and/or nitro1~C20An alkoxy group; haloalkyl radicals such as-CF3(ii) a Each independently is hydroxyl, carboxyl, carbonyl and amino which are unsubstituted or substituted by halogen atoms, cyano and/or nitro; substituted by C1~C10Amino of an alkyl group; substituted by C5~C30Aryl and/or C4~C30An amino group of a heteroaryl group; a nitro group; a hydrazine group; a sulfonyl group; c1~C20An alkylsilyl group; c1~C20An alkoxysilyl group; c3~C30A cycloalkylsilyl group; c5~C30An alkylsilyl group; c5~C30An aryl group; c4~C30A heteroaryl group; c5~C30Aralkyl group; c4~C30A heteroaralkyl group; c5~C30An aryloxy group; c4~C30A heteroaryloxy group; and so on.
C4~C30The aromatic or heteroaromatic group may include, but is not limited to, C5~C30Aryl radical, C4~C30Heteroaryl group, C5~C30Aralkyl radical, C4~C30Heteroaralkyl radical, C5~C30Aryloxy radical, C4~C30Heteroaryloxy radical, C5~C30Arylamino and/or C4~C30A heteroarylamino group.
For example, R of
In this case, when R is formed in
In an exemplary embodiment, L as a linker in
In an alternative embodiment, at L1And/or L2Is unsubstituted or substituted C4~C30In the case of heteroarylene, L1And/or L2Each may be independently selected from the group consisting of, but not limited to: pyrrolylene, imidazolyl, pyrazolyl, pyridyl, pyrazinylene, pyrimidinyl, pyridazinylene, indolyl, isoindolylene, indazolylene, purinylene, quinolinylene, isoquinolylene, benzoquinolinylene, phthalazinylene, naphthyridinylene, quinoxalylene, quinazolinylene, benzoisoquinolinylene, benzoquinazolinylene, benzoquinoxalylene, cinnolinylene, phenanthridinylene, acridinylene, phenanthrolinylene, phenazinylene, benzoxazolyl, benzimidazolylene, furanylene, benzofuranylene, dibenzofuranylene, thiophenylene, benzothiophenylene, thiazolyl, isothiazolylene, benzothiazolyl, oxazolylene, isoxazolylene, triazolylene, tetrazolylene, oxadiazoylene, triazinylene, benzofurandibenzofuranylene, benzothiophenylbenzofuranylene, benzofuranylene, Benzothiophene dibenzofuranylene, benzothiophene, dibenzothiophenylene, benzothiophene, benzothiophene dibenzothiophenylene, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, indolocarbazolylene, indenocarbazolyleneA group, a benzofurancarbazolyl group, a benzothiophenecarbonyl group, an imidazopyrimidinyl group and an imidazopyridinyl group, each of which is unsubstituted or substituted with C4~C30An aromatic or heteroaromatic group.
In an exemplary embodiment, when L is formed separately1And/or L2As the number of aromatic or heteroaromatic rings becomes larger, the entire organic compound can have a long conjugated structure, and thus the energy band gap thereof can be significantly reduced. Preferably, L in
In one exemplary embodiment, R1And R2Each of which may be directly or via a linker L1And L2To the ortho, meta or para position of the spiro-anthracene nucleus, preferably to the meta or para position.
Since the organic compound represented by
In one exemplary embodiment, the organic compound of the present disclosure can be an organic compound having a spiro-anthracene nucleus and an aromatic or heteroaromatic group bound (attached or combined) to the spiro-anthracene nucleus. The aromatic or heteroaromatic group can be bound directly to the spiro-anthracene nucleus, or to the spiro-anthracene nucleus through an aromatic or heteroaromatic linker. Such an organic compound may have a structure of the following chemical formula 2:
chemical formula 2
In chemical formula 2, R11And R12Each independently selected from the group consisting of: unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryl, and unsubstituted or substituted with C4~C30C of aromatic or heteroaromatic radicals4~C30A heteroaryl group. L is3And L4Each independently selected from the group consisting of: unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Arylene, and unsubstituted or substituted with C4~C30C of aromatic or heteroaromatic radicals4~C30A heteroarylene group. o and p are each independently 0 (zero) or 1, and at least one of o and p is 1. m, n and X are each the same as defined in
In one exemplary embodiment, R in chemical formula 211And/or R12Each of the aryl and heteroaryl groups of (a) may include the aryl and heteroaryl groups illustrated in
In alternative exemplary embodiments, the organic compounds of the present disclosure may be organic compounds having a spiro-anthracene nucleus incorporating an aromatic or heteroaromatic amino group. Such an organic compound may have a structure of the following chemical formula 3:
chemical formula (II)3
In chemical formula 3, R21To R24Each independently selected from the group consisting of: unsubstituted or substituted by C4~C30C of aromatic or heteroaromatic radicals5~C30Aryl, and unsubstituted or substituted with C4~C30C of aromatic or heteroaromatic radicals4~C30A heteroaryl group. o and p are each independently 0 (zero) or 1, and at least one of o and p is 1. X is the same as defined in
In one exemplary embodiment, R in chemical formula 321To R24The aryl and heteroaryl groups of (a) may each include aryl and heteroaryl groups illustrated in
As an example, R in chemical formula 211And R12Each of which may include an imidazolyl group and a thiazolyl group, which have no substituent or are substituted with a phenyl group, respectively, and R in chemical formula 321To R24Each may include a phenyl group. In particular, the organic compound of the present disclosure may have one of the structures of the following chemical formula 4:
The organic compounds represented by the above chemical formulas 2 to 4 each have a structurally rigid spiro-anthracene nucleus incorporating an aromatic or heteroaromatic group or an amino group substituted with an aromatic or heteroaromatic group. The organic compounds each have enhanced color purity, and can be used as a light-emitting compound to improve the light-emitting efficiency of an organic light-emitting diode or an organic light-emitting device.
[ organic light emitting diode and device ]
As described above, the organic compounds represented by
As shown in fig. 1, the organic light emitting
The
The
A
A
A
An interlayer insulating
The interlayer insulating
A
The
Although not shown in fig. 1, gate and data lines crossing each other to define a pixel region, and a switching element connected to the gate and data lines may be further formed in the pixel region. The switching element is connected to a thin film transistor Tr as a driving element. Further, the power line is spaced in parallel with the gate line or the data line, and the thin film transistor Tr may further include a storage capacitor configured to constantly maintain the voltage of the gate electrode for one frame.
In addition, the organic light emitting
For example, when the organic light emitting
A
The organic
The
In one exemplary embodiment, when the organic light emitting
In addition, a
The
The
In addition, an
The
Fig. 2 is a schematic cross-sectional view illustrating an organic light emitting diode having an organic compound as a fluorescent dopant in a single EML according to an exemplary embodiment of the present disclosure.
As shown in fig. 2, an Organic Light Emitting Diode (OLED)100 of an exemplary embodiment of the present disclosure includes a
The
The
The
The
The EML160 may include a host and a dopant. In this exemplary embodiment, the EML160 may include a host (first host) and an organic compound represented by any one of
The host of EML160 may include, but is not limited to, 9- (3- (9H-carbazol-9-yl) phenyl) -9H-carbazole-3-carbonitrile (mCP-CN), CBP, 3 '-bis (N-carbazolyl) -1, 1' -biphenyl (mCBP), 1, 3-bis (carbazol-9-yl) benzene (mCP), oxybis (2, 1-phenylene)) bis (diphenylphosphine oxide (DPEPO), 2, 8-bis (diphenylphosphoryl) dibenzothiophene (PPT), 1,3, 5-tris [ (3-pyridyl) -benzene-3-yl ] benzene (tmpb), 2, 6-bis (9H-carbazol-9-yl) pyridine (PYD-2 z), 2, 8-bis (9H-carbazol-9-yl) dibenzothiophene (DCzDBT), 3 ', 5 ' -bis (carbazol-9-yl) - [1,1 ' -diphenyl ] -3, 5-dinitrile (DCzTPA), 4 ' - (9H-carbazol-9-yl) biphenyl-3, 5-dinitrile (pCzB-2CN), 3 ' - (9H-carbazol-9-yl) biphenyl-3, 5-dinitrile (mCZB-2CN), diphenyl-4-triphenylsilylphenyl-phosphine oxide (TPSO1), 9- (9-phenyl-9H-carbazol-6-yl) -9H-carbazole (CCP), 4- (3- (triphenylen-2-yl) phenyl) dibenzo [ b, d ] thiophene, 9- (4- (9H-carbazol-9-yl) phenyl) -9H-3, 9' -bicarbazole, 9- (3- (9H-carbazol-9-yl) phenyl) -9H-3, 9' -bicarbazole and/or 9- (6- (9H-carbazol-9-yl) pyridin-3-yl) -9H-3, 9' -bicarbazole.
Specifically, a host that can be used for the EML160 may include, but is not limited to, one of H1 to H5 represented by the structure of the following chemical formula 5:
chemical formula 5
In this case, the excited state singlet energy level S of the host1 HAnd/or excited triplet level T1 HHigher than excited singlet level S of the first fluorescent dopant1 FDAnd/or excited triplet level T1 FD(see FIG. 3).
The ETL170 and the
In an exemplary embodiment, the ETL170 may include, but is not limited to, oxadiazole compounds, triazole compounds, phenanthroline compounds, benzoxazole compounds, benzothiazole compounds, benzimidazole compounds, triazine compounds, and the like.
For example, ETL170 may include, but is not limited to, tris- (8-hydroxyquinoline)Aluminum (Alq)3) 2-biphenyl-4-yl-5- (4-tert-butylphenyl) -1,3, 4-oxadiazole (PBD), spiro-PBD, lithium quinoline (Liq), 1,3, 5-tris (N-phenylbenzimidazol-2-yl) benzene (TPBi), bis (2-methyl-8-hydroxyquinoline-N1, O8) - (1, 1' -biphenyl-4-hydroxy) aluminum (BAlq), 4, 7-diphenyl-1, 10-phenanthroline (Bphen), 2, 9-bis (naphthalen-2-yl) 4, 7-diphenyl-1, 10-phenanthroline (NBphen), 2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline (BCP), 3- (4-biphenylyl) -4-phenyl-5-tert-butylphenyl-1, 2, 4-Triazole (TAZ), 4- (naphthalen-1-yl) -3, 5-diphenyl-4H-1, 2, 4-triazole (NTAZ), 1,3, 5-tris (p-pyridin-3-yl-phenyl) benzene (TpPyPB), 2,4, 6-tris (3 '- (pyridin-3-yl) biphenyl-3-yl) 1,3, 5-triazine (TmPPPyTz), poly [9, 9-bis (3' - ((N, N-dimethyl) -N-ethylammonium) -propyl) -2, 7-fluorene]-alt-2,7- (9, 9-dioctylfluorene)](PFNBr) and/or tris (phenylquinoxaline) (TPQ).
The
In one exemplary embodiment, when the EML160 includes a host and a first fluorescent dopant that may be an organic compound represented by any one of
As shown in FIG. 3, the excited state singlet energy level S of the host1 HAnd excited state triplet level T1 HRespectively higher than the excited singlet level S of the first fluorescent dopant1 FDAnd excited state triplet level T1 FDSo that exciton energy generated in the host can be transferred to the first fluorescent dopant. In one exemplary embodiment, the emission wavelength range of the host may overlap more with the absorption wavelength range of the first fluorescent dopantSo that exciton energy can be efficiently transferred from the host to the first fluorescent dopant.
Since the EML160 includes an organic compound represented by any one of
When the EML160 includes only the host and the fluorescent dopant in the above embodiments, the EML may have two or more dopants. Fig. 4 is a schematic cross-sectional view illustrating an OLED having a host in a single layer EML, a delayed fluorescence material as a first dopant, and an organic compound represented by any one of
In one exemplary embodiment, the
In this embodiment, the EML160a may include a host (first host), a first dopant, and a second dopant. The first dopant may be a delayed fluorescence dopant (T-dopant), for example a thermally activated delayed fluorescence dopant, and the second dopant may be a fluorescence dopant (F-dopant). For example, an organic compound represented by any one of
Delayed fluorescence can be classified into Thermally Activated Delayed Fluorescence (TADF) and Field Activated Delayed Fluorescence (FADF). The triplet excitons can be activated by a thermal or electric field in delayed fluorescence, so that super fluorescence exceeding the maximum luminous efficiency of conventional fluorescent materials can be realized.
Since triplet excitons within the delayed fluorescent material may be activated by heat or an electric field generated during driving of the diode, the triplet excitons may be included in the emission process, as shown in fig. 5, which is a schematic view illustrating a light emitting mechanism of the delayed fluorescent material in the EML according to another exemplary embodiment of the present disclosure.
Since the delayed fluorescent material generally has an electron donor moiety and an electron acceptor moiety, it can be converted into an Intramolecular Charge Transfer (ICT) state. In the case of using a delayed fluorescent material convertible into an ICT state as a dopant, the singlet level S1Exciton and triplet level T1May be moved to an intermediate energy level state, i.e., ICT state, and then the excitons in the intermediate state may be moved to a ground state (S)0;S1→ICT←T1). Due to the singlet energy level S in the delayed fluorescent material1Exciton and triplet level T1The excitons of (a) are involved in the emission process, so that the delayed fluorescent material can improve internal quantum efficiency and luminous efficiency.
Since the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO) are widely distributed throughout the molecule in common fluorescent materials, it is not possible to exchange between singlet and triplet energy levels (selection rules). In contrast, since the delayed fluorescent material that can be converted into the ICT state has almost no orbital overlap between the HOMO and LUMO, there is almost no interaction between the HOMO-state molecular orbital and the LUMO-state molecular orbital in the delayed fluorescent material. As a result, the change in the spin state of the electron has no influence on other electrons, and a new charge transfer band (CT band) that does not follow the selection rule is formed in the delayed fluorescent material.
In other words, since the delayed fluorescent material has an electron acceptor moiety separated from an electron donor moiety within the molecule, it exists in a polarized state having a large dipole moment within the molecule. Due to the polarization state of the dipole moment, the interaction between the HOMO molecular orbital and the LUMO molecular orbital becomes small, and both the triplet-level excitons and the singlet-level excitons can be converted into the ICT state. Thus, the triplet level T1Excitons and singlet states ofEnergy level S1Can participate in the emission process.
In the case of driving a diode containing a delayed fluorescent material, 25% of the singlet energy level S1And 75% of the triplet level T1Is converted into an ICT state by heat or an electric field, and then the converted exciton is transferred to a ground state S by luminescence0. Therefore, the delayed fluorescent material can theoretically have an internal quantum efficiency of 100%.
Delayed fluorescent material at singlet energy level S1And triplet state energy level T1Must have a Δ E equal to or less than about 0.3eV (e.g., about 0.05 to about 0.3eV)ST TDSo that the exciton energy in both the singlet and triplet energy levels can be transferred to the ICT state. Singlet energy level S1And triplet state energy level T1Materials having a small energy band gap therebetween can exhibit ordinary fluorescence by intersystem crossing (ISC) in which the singlet energy level S1The exciton can be transferred to the triplet level T1An exciton of (a); and exhibits delayed fluorescence by reverse intersystem crossing, wherein the triplet level T1The exciton can be transferred upwards to a singlet energy level S1Then singlet energy level S1May be transferred to the ground state S0。
Since the delayed fluorescent material can theoretically exhibit an internal quantum efficiency of 100%, it can achieve as high a luminous efficiency as a conventional phosphorescent material including a heavy metal. However, due to the bonding configuration between the electron acceptor-electron donor and the spatial twist in the delayed fluorescent material, and the additional charge transfer transition (CT transition) caused by them, the delayed fluorescent material shows a broad spectrum during emission, which causes poor color purity.
In one exemplary embodiment of the present disclosure, the EML160A includes a compound represented by any one of
In this case, since the final emission in the EML160A is performed at the second dopant, i.e., the compound represented by any one of
In exemplary embodiments, the host in EML160a may be mCP-CN, CBP, mCBP, mCP, DPEPO, TmPyPB, PYD-2Cz, DCzDBT, DCzTPA, pCzB-2CN, mCzB-2CN, TPSO1, CCP, 4- (3- (triphenylen-2-yl) phenyl) dibenzo [ b, d ] thiophene, 9- (4- (9H-carbazol-9-yl) phenyl) -9H-3, 9' -bicarbazole, 9- (3- (9H-carbazol-9-yl) phenyl) -9H-3, 9' -bicarbazole and/or 9- (6- (9H-carbazol-9-yl) pyridin-3-yl) -9H-3, 9' -bicarbazole, but is not limited thereto.
In another exemplary embodiment, the first dopant (delayed fluorescence dopant) used in EML160a may be bis (4- (9H-carbazol-9-yl) phenyl) methanone (Cz2BP), 9- (3- (9H-carbazol-9-yl) -5- (4, 6-diphenyl-1, 3, 5-triazin-2-yl) phenyl) -9H-carbazole (DcrTrZ), 3- (9H-carbazol-9-yl) -9- (4- (4, 6-diphenyl-1, 3, 5-triazin-2-yl) phenyl) -9H-carbazole (4-DcrTrZ), 10- (4- (4, 6-diphenyl-1, 3, 5-triazin-2-yl) phenyl) -10H-spiro [ acridine-9, 9' -xanthene ], 4, 5-bis (9H-carbazol-9-yl) phthalonitrile (2CzPN), 2,4,5, 6-tetrakis (9H-carbazol-9-yl) isophthalonitrile (4CzIPN), 3,4,5, 6-tetrakis (carbazol-9-yl) -1, 2-dicyanobenzene (4CzPN), 4 ' -bis (10H-phenoxazin-10-yl) - [1,1:2, 1-terphenyl ] -4, 5-dinitrile (Px-VPN), 9' - (5- (4, 6-diphenyl-1, 3, 5-triazin-2-yl) benzene-1, 2, 3-triyl) tris (9H-carbazole (TczTRZ) and/or 12- (4- (4, 6-diphenyl-1, 3, 5-triazin-2-yl) phenyl-5-phenyl-5, 12-indolino [3,2-a ] carbazole (32alCTRZ), but is not limited thereto.
Chemical formula 6
Thus, when the EML160a includes a host (first host), a delayed fluorescence dopant (first dopant), and an organic compound represented by any one of
In other words, the EML160a of the second embodiment of the present disclosure includes an organic compound represented by any one of
Fig. 6 is a schematic diagram illustrating a light emission mechanism by an energy level bandgap between a host, a first dopant (delayed fluorescence dopant), and a second dopant (fluorescence dopant) in an EML according to another exemplary embodiment of the present disclosure. Referring to FIG. 6, an excited state singlet energy level S of a host1 HAnd excited state triplet energy T1 HEach must be higher than the excited singlet energy level S of the delayed fluorescent dopant1 TDAnd excited state triplet level T1 TDSo that exciton energy generated in the host can be transferred to the delayed fluorescence dopant in advance.
As excited state triplet energy level T of the host1 HNot higher than excited triplet level T of the delayed fluorescent dopant1 TDRetardation of triplet state T of fluorescent dopant1 TDThe exciton can be transferred to an excited state triplet level of the hostT1 H. Thus, the triplet state T of the fluorescent dopant is delayed1 TDCan disappear as non-emission and they cannot contribute to emission. E.g. excited triplet state energy level T compared to the first dopant1 TDExcited triplet level T of the host1 HMay be at least 0.2eV higher.
In addition, the properties of the host and the delayed fluorescence dopant, the Highest Occupied Molecular Orbital (HOMO) level and the Lowest Unoccupied Molecular Orbital (LUMO) level, need to be adjusted. For example, it is preferable that the highest occupied molecular orbital energy level (HOMO) of the hostH) And a highest occupied molecular orbital energy level (HOMO) of the delayed fluorescent dopantTD) Energy level band gap (| HOMO)H-HOMOTD| or lowest unoccupied molecular orbital Level (LUMO) of the hostH) And a lowest unoccupied molecular orbital Level (LUMO) of the first dopantTD) Bandgap of energy level (| LUMO)H-LUMOTD|) may be equal to or less than about 0.5eV, for example from about 0.1eV to about 0.5 eV. In this case, charges can be efficiently moved from the host to the delayed fluorescence dopant, thereby enhancing the final light emitting efficiency.
In addition, it is desirable to realize an OLED that can transfer energy from a delayed fluorescence dopant (which has been converted into an ICT complex state by RISC) to a second dopant of a fluorescent material in the EML160a and has high luminous efficiency and color purity. To realize such an OLED, the excited singlet energy level S of the first dopant1 TDAnd/or excited triplet level T1 TDEach must be higher than the excited singlet energy level S of the second dopant1 FDAnd/or excited triplet level T1 FD。
When the EML160a includes a host, a delayed fluorescence dopant (first dopant), and a fluorescence dopant (second dopant), it may include a host in a weight ratio exceeding the dopant. In one embodiment, the EML160a may include a first dopant in a weight ratio that exceeds a second dopant. For example, the content of the host by weight in the EML160a may be greater than the content of the first dopant, and the content of the first dopant by weight in the EML160a may be greater than the content of the second dopant. In this case, the exciton energy in EML160a may be efficiently transferred from the first dopant to the second dopant. For example, when the EML160a includes a host, a delayed fluorescence dopant (first dopant), and a fluorescence dopant (second dopant), the first and second dopants may constitute about 1 wt% to about 50 wt% of the EML160 a.
Additionally, the OLEDs of the present disclosure may also include one or more exciton blocking layers. Fig. 7 is a schematic cross-sectional view illustrating an organic light emitting diode having an organic compound as a fluorescent dopant in a single-layered EML according to another exemplary embodiment of the present disclosure. As shown in fig. 7, the third embodiment of the present disclosure includes a
In one exemplary embodiment, the
As described above, the
The
The
The EML260 may include a host (first host) and at least one dopant. In one exemplary embodiment, the EML260 may include a host and an organic compound represented by any one of
In another exemplary embodiment, the EML260 may include a host (first host), a first dopant, and a second dopant. The first dopant may be a delayed fluorescence dopant and the second dopant may be a fluorescence dopant. An organic compound represented by any one of
In an exemplary embodiment, the body may be mCP-CN, CBP, mCBP, MCP, DPEPO, PPT, TmPyPB, PYD-2CZ, DCzDBT, DCzTPA, pCzB-2CN, mCZB-2CN, TPSO1, CCP, 4- (3- (triphenylen-2-yl) phenyl) dibenzo [ b, d ] thiophene, 9- (4- (9H-carbazol-9-yl) phenyl) -9H-3, 9' -bicarbazole, 9- (3- (9H-carbazol-9-yl) phenyl) -9H-3, 9' -bicarbazole and/or 9- (6- (9H-carbazol-9-yl) pyridin-3-yl) -9H-3, 9' -bicarbazole, but is not limited thereto. In particular, the body may include, but is not limited to, any one of H1 to H5 represented by the above chemical formula 5.
The first dopant can be Cz2BP, DcrTrZ, 4-DcrTrZ, 10- (4- (4, 6-diphenyl-1, 3, 5-triazin-2-yl) phenyl) -10H-spiro [ acridine-9, 9' -xanthene ], 2CzPN, 4CzIPN, 4CzPN, Px-VPN, TczTRZ, and/or 32alcTRZ), but is not so limited. In particular, the delayed fluorescence dopant may be, but is not limited to, any one of the above chemical formula 6.
In this case, the excited singlet level S of the first dopant1 TDAnd excited state triplet level T1 TDMay be equal to or less than about 0.3 eV. In addition, the excited singlet level S of the host1 HAnd/or excited triplet level T1 HHigher than the excited singlet level S of the first dopant1 TDAnd/or excited triplet level T1 TD. For example, excited triplet level T of the host1 HExcited triplet level T of comparable first dopant1 TDAt least about 0.2eV higher. Further, an excited singlet energy level S of the first dopant1 TDAnd/or excited triplet level T1 TDHigher than excited singlet level S of the second dopant1 FDAnd/or excited triplet level T1 FD。
In addition, the highest occupied molecular orbital level (HOMO) of the hostH) And a highest occupied molecular orbital energy level (HOMO) of the first dopantTD) Energy level band gap (| HOMO)H-HOMOTDL) or lowest unoccupied molecular orbital Level (LUMO) of the first hostH) And a lowest unoccupied molecular orbital Level (LUMO) of the first dopantTD) Bandgap of energy level (| LUMO)H-LUMOTD|) may be equal to or less than about 0.5 eV. Where the EML260 includes a host, a first dopant, and a second dopant, the EML260 may include about 1 wt% to about 50 wt% of the first and second dopants.
The ETL270 is disposed between the EML260 and the
The
The
For example, the
In addition, the
For example, HBL275 may comprise a compound having a relatively low HOMO energy level compared to the emissive material in
The
The OLED of the foregoing embodiment has only a single emitting material layer. Alternatively, the OLEDs of the present disclosure may comprise multiple layers of emissive material. Fig. 8 is a schematic cross-sectional view illustrating an organic light emitting diode having a host, a delayed fluorescent material, and an organic compound as a fluorescent dopant in a dual-layer EML according to another exemplary embodiment of the present disclosure.
As shown in fig. 8, the
In one exemplary embodiment, the
In this embodiment, EML360 includes a first EML (EML1)362 disposed between
The EML1362 may include a first host and a first fluorescent dopant, which is an organic compound represented by any one of
In contrast, EML2364 may include a second host and a delayed fluorescence dopant. The delayed fluorescence dopant in EML2364 has an excited triplet level T1 TDAnd excited singlet energy level S1 TDI.e., equal to or less than about 0.5eV, and its excited state triplet energy can be transferred to its excited state singlet energy by RISC. When the delayed fluorescence dopant has high quantum efficiency, it shows poor color purity due to its wide FWHM.
However, in this exemplary embodiment, both the singlet and triplet energies of the delayed fluorescent dopant in EML2364 may be transferred to the first fluorescent dopant contained in EML1362, the EML1362 being disposed adjacent to EML2364 by FRET (forster resonance energy transfer), which transfers energy non-radially through dipole-dipole interaction. Thus, the final emission is completed at the first fluorescent dopant in EML 1362.
In other words, the triplet energy of the delayed fluorescent dopant is converted into the singlet energy of the delayed fluorescent dopant in the EML2364 by RISC, and the singlet energy of the delayed fluorescent dopant is transferred to the singlet energy of the first fluorescent dopant because the excited-state singlet level S of the delayed fluorescent dopant1 TDHigher than excited singlet level S of the first fluorescent dopant1 FD(see fig. 9). The first fluorescent dopant in EML1362 can emit light using singlet and triplet energies. Accordingly, the
In this case, the delayed fluorescence dopant is used only to transfer energy to the first fluorescence dopant. EML2364 containing a delayed fluorescence dopant does not participate in the final emission process, while EML1362 containing a first fluorescence dopant emits light.
EML1362 and EML2364 include first and second bodies, respectively. For example, the first and second bodies may be mCP-CN, CBP, mCBP, MCP, DPEPO, PPT, TmPyPB, PYD-2CZ, DCzDBT, respectively, DCzTPA, pCzB-2CN, mCZB-2CN, TPSO1, CCP, 4- (3- (triphenylen-2-yl) phenyl) dibenzo [ b, d ] thiophene, 9- (4- (9H-carbazol-9-yl) phenyl) -9H-3, 9' -bicarbazole, 9- (3- (9H-carbazol-9-yl) phenyl) -9H-3, 9' -bicarbazole and/or 9- (6- (9H-carbazol-9-yl) pyridin-3-yl) -9H-3, 9' -bicarbazole, but is not limited thereto. In particular, the first body and the second body may include, but are not limited to, any one of H1 through H5 represented by the above chemical formula 5, respectively.
Further, the delayed fluorescence dopant contained in EML2364 may be Cz2BP, DcrTrZ, 4-DcrTrZ, 10- (4- (4, 6-diphenyl-1, 3, 5-triazin-2-yl) phenyl) -10H-spiro [ acridine-9, 9' -xanthene ], 2CzPN, 4CzIPN, 4CzPN, Px-VPN, TczTRZ and/or 32alcTRZ), but is not limited thereto. In particular, the delayed fluorescence dopant may be, but is not limited to, any one of the above chemical formula 6.
In one exemplary embodiment, the weight ratio of each of the first host and the second host may exceed the first fluorescent dopant and the delayed fluorescent dopant in the EML1362 and the EML2364, respectively. Further, the weight ratio of the delayed fluorescence dopant in EML2364 may exceed the weight ratio of the first fluorescence dopant in EML 1362. In this case, energy may be transferred from the delayed fluorescence dopant in EML2364 to the first fluorescence dopant in EML 1362.
Now, the energy level relationship between materials in the EML360 will be described, and the EML360 includes the dual-
In addition, excited singlet level S of the second host1 H2And excited state triplet level T1 H2Are respectively higher than the excited state singlet state energy level S of the delayed fluorescence dopant in EML23641 TDAnd excited state triplet level T1 TD. In addition, the excited singlet level S of the delayed fluorescent dopant in EML23641 TDHigher thanExcited state singlet level S of fluorescent dopant in EML13621 FD。
If the EML360 does not satisfy the energy level condition, a quenching phenomenon exists at both the delayed fluorescence dopant and the fluorescent dopant and/or energy cannot be transferred from the delayed fluorescence dopant to the fluorescent dopant. As a result, the quantum efficiency of the
In one exemplary embodiment, the excited singlet energy level S1 TDAnd excited state triplet level T1 TDThe band gap therebetween may be equal to or less than about 0.3 eV. Furthermore, the highest occupied molecular orbital energy level (HOMO) of the first and/or second hostH) And a highest occupied molecular orbital energy level (HOMO) of the delayed fluorescent dopantTD) Energy level band gap (| HOMO)H-HOMOTDL) or the lowest unoccupied molecular orbital Level (LUMO) of the first and/or second hostH) And a lowest unoccupied molecular orbital Level (LUMO) of the first dopantTD) Bandgap of energy level (| LUMO)H-LUMOTD|) may be equal to or less than about 0.5 eV.
In an alternative exemplary embodiment, the first host included in the EML1362 together with the first fluorescent dopant (i.e., the organic compound represented by any one of
In another exemplary embodiment, EML1362 may include the second host and the delayed fluorescence dopant, and EML2364 may include the first host and the first fluorescence dopant (i.e., the organic compound represented by any one of
An OLED with three layers of EMLs will be explained. Fig. 10 is a schematic cross-sectional view of an organic light emitting diode having a host, a delayed fluorescent material, and an organic compound as a fluorescent dopant in a three-layered EML according to another exemplary embodiment of the present disclosure. As shown in fig. 10, the
In one exemplary embodiment, the
In this embodiment, the EML460 includes a first EML (EML1)462 disposed between the
According to this embodiment, both the singlet energy and the triplet energy of the delayed fluorescent dopant in the EML2464 can be transferred to the first fluorescent dopant and the second fluorescent dopant respectively contained in the EML1462 and the EML 3466, and the EML1462 and the EML 3466 are disposed adjacent to the EML2464 by the FRET energy transfer mechanism. Thus, the final emission is completed at the first fluorescent dopant and the second fluorescent dopant in EML1462 and EML 3466.
In other words, the triplet energy of the delayed fluorescent dopant is converted into the singlet energy of the delayed fluorescent dopant in the EML2464 by RISC, and the singlet energy of the delayed fluorescent dopant is transferred to the singlet energies of the first and second fluorescent dopants because the excited-state singlet level S of the delayed fluorescent dopant1 TDHigher than excited singlet level S of the first and second fluorescent dopants1 FD1And S1 FD2(see FIG. 11). The first and second fluorescent dopants in EML1462 and EML 3466 may emit light using singlet and triplet energies. Accordingly, the
In this case, the delayed fluorescence dopant is used only to transfer energy to the first fluorescence dopant and the second fluorescence dopant. The final emission process did not involve EML2464 containing the delayed fluorescence dopant, while EML1462 containing the first fluorescence dopant and EML 3466 containing the second fluorescence dopant emitted light.
EML1462, EML2464, and EML 3466 include first, second, and third bodies, respectively. For example, the first, second and third hosts may be mCP-CN, CBP, mCBP, MCP, DPEPO, PPT, TmPyPB, PYD-2CZ, DCzDBT, DCzTPA, pCzB-2CN, mCZB-2CN, TPSO1, CCP, 4- (3- (triphenylen-2-yl) phenyl) dibenzo [ b, d ] thiophene, 9- (4- (9H-carbazol-9-yl) phenyl) -9H-3, 9' -bicarbazole, 9- (3- (9H-carbazol-9-yl) phenyl) -9H-3, 9' -bicarbazole and/or 9- (6- (9H-carbazol-9-yl) pyridin-3-yl) -9H-3, 9' -bicarbazole, respectively, but is not limited thereto. In particular, each of the first, second and third bodies may include, but is not limited to, any one of H1 through H5 represented by the above chemical formula 5.
Further, the delayed fluorescence dopant contained in EML2464 may be Cz2BP, DcrTrZ, 4-DcrTrZ, 10- (4- (4, 6-diphenyl-1, 3, 5-triazin-2-yl) phenyl) -10H-spiro [ acridine-9, 9' -xanthene ], 2CzPN, 4CzIPN, 4CzPN, Px-VPN, TczTRZ and/or 32alcTRZ), but is not limited thereto. In particular, the delayed fluorescence dopant may be, but is not limited to, any one of the above chemical formula 6.
In one exemplary embodiment, the first to third hosts may each have a weight ratio exceeding the first fluorescent dopant, the delayed fluorescent dopant, and the second fluorescent dopant in the EML1462, the EML2464, and the EML 3466, respectively. Further, the weight ratio of the delayed fluorescence dopant in the EML2464 may exceed the weight ratio of the first fluorescence dopant in the EML1462 and the second fluorescence dopant in the EML 3464. In this case, energy may be transferred from the delayed fluorescence dopant in EML2464 to the first fluorescence dopant in EML1362 and the second fluorescence dopant in EML 3466.
The energy level relationship between materials in the EML460 will be explained, and the EML460 includes
In addition, excited singlet level S of the second host1 H2And excited state triplet level T1 H2Are respectively higher than the excited state singlet state energy level S of the delayed fluorescence dopant in EML24641 TDAnd excited state triplet level T1 TD. In addition, the excited state triplet level T of the first host in EML14621 H1And excited state triplet level T of the third host in EML 34661 H3Respectively higher than the excited triplet level T of the delayed fluorescence dopant in EML24641 TD. In addition, excited state singlet of delayed fluorescence dopant in EML2464State energy level S1 TDHigher than excited state singlet state energy level S of the first and second fluorescent dopants in EML1462 and EML 34661 FD1And S1 FD2。
In one exemplary embodiment, the excited singlet energy level S1 TDAnd excited state triplet level T1 TDThe band gap therebetween may be equal to or less than about 0.3 eV. Furthermore, the highest occupied molecular orbital energy level (HOMO) of the first, second and/or third hostH) And a highest occupied molecular orbital energy level (HOMO) of the delayed fluorescent dopantTD) Energy level band gap (| HOMO)H-HOMOTDL) or the lowest unoccupied molecular orbital Level (LUMO) of the first, second and/or third hostH) And a lowest unoccupied molecular orbital Level (LUMO) of the first dopantTD) Bandgap of energy level (| LUMO)H-LUMOTD|) may be equal to or less than about 0.5 eV.
In an alternative exemplary embodiment, the first body included in the EML1462 together with the first fluorescent dopant (i.e., the organic compound represented by any one of
In one exemplary embodiment, the third host included in the EML 1466 together with the second fluorescent dopant (i.e., the organic compound represented by any one of
In yet another exemplary embodiment, the first body in EML1462 may be the same material as
Synthesis example 1: synthesis of Compound 2
(1) Synthesis of intermediate A-1(2- (4-bromophenyl) -1,4, 5-triphenyl-1H-imidazole)
5.00g (27.03mmol) of 4-bromobenzaldehyde, 12.58g (135.13mmol) of aniline, 5.68g (27.03mmol) of benzil and 8.33g (108.10mmol) of ammonium acetate were placed in a 500mL two-necked flask and dissolved in 250mL of acetic acid. The reaction mixture was then refluxed and stirred for 3 hours. After completion of the reaction, the precipitated solid was filtered and washed with an acetic acid/water (3:1) solution to obtain 9.15g of a white powder (yield: 75%).
(2) Synthesis of intermediate A-2(1,4, 5-triphenyl-2- (4- (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborolan-2-yl) phenyl) -1H-imidazole)
5.00g (11.08mmol) of intermediate A-1, 8.44g (33.23mmol) of bis (pinacol) diboron, 0.30g (0.33mmol) of Pd2(dba)3(tris (dibenzylideneacetone) dipalladium (0)), 0.32g (0.66mmol) of XPhos (2-dicyclohexylphosphine-2 ', 4 ', 6 ' -triisopropylbiphenyl), 3.81g (38.77mmol) of KOAc (potassium acetate) were placed in a 500mL two-necked flask and dissolved in 200mL of 1, 4-dioxane. The reaction mixture was then refluxed and stirred for 12 hours. After the completion of the reaction, column chromatography was performed using hexane/ethyl acetate (10:1) as a developing solvent to obtain 4.80g of A-2 as a solid (yield: 88.07%).
(3) Synthesis of intermediate B-2(4,4,5, 5-tetramethyl-2- (spiro [ benzo [ d, e ] anthracene-7, 9' -fluorene ] -9-yl) -1,3, 2-dioxaborane)
2.00g (4.99mmol) of Compound B-1, 3.80g (14.97mmol) of bis (pinacol) diboron, 0.14g (0.15mmol) of Pd2(dba)30.14g (0.30mmol) of XPhos, 1.71g (17.46mmol) of KOAc were placed in a 250mL two-necked flask and dissolved in 70mL of 1, 4-dioxane. The reaction mixture was then refluxed and stirred for 12 hours. After completion of the reaction, column chromatography was performed using hexane/ethyl acetate (10:1) as a developing solvent to obtain 2.1g of solid B-2 (yield: 85.5%).
(4) Synthesis of intermediate B-3 (5-bromo-2- (spiro [ benzo [ d, e ] anthracene-7, 9' -fluorene ] -9-yl-methyl benzoate)
2.00g (4.06mmol) of intermediate B-2,1.66g (4.87mmol) of methyl 5-bromo-2-iodobenzoate, 2.81g (20.31mmol) of K2CO30.14g (0.12mmol) of Pd (PPh)3)4(tetrakis (triphenylphosphine) palladium (0)) was placed in a 250mL two-necked flask and dissolved in 70mL of THF/water (3:1), a mixed solvent. The reaction mixture was then refluxed and stirred for 12 hours. After completion of the reaction, column chromatography was performed using methylene chloride/hexane (3:7) as a developing solvent to obtain 1.8g of solid B-3 (yield: 54.68%).
(5) Synthesis of intermediate B-4(2- (5-chloro-2- (spiro [ benzo [ d, e ] anthracene-7, 9' -fluoren ] -9-yl) phenyl) propan-2-ol)
1.80g (3.11mmol) of intermediate B-3 were placed in a 250mL two-necked flask, dissolved in 70mL of diethyl ether and cooled to 0 ℃. Then, 1.11g (9.32mmol,3M) of CH3MgBr was added dropwise to the flask and slowly raised to the chamberAnd (4) warming. After the completion of the reaction, water was added and the resulting solid was filtered to obtain 1.75g of intermediate B-4 (yield: 97.2%).
(6) Synthesis of intermediate B-5 (11-bromo-13, 13-dimethyl-13H-spiro [ benzo [ f, g ] indeno [1,2-B ] anthracene-7, 9' -fluorene ])
1.80g (3.11mmol) of intermediate B-4 were placed in a 250mL two-necked flask, dissolved in 70mL of diethyl ether and cooled to 0 ℃. Then, 0.22g (1.55mmol) of BF was added3Et2O was added dropwise to the flask and slowly warmed to room temperature, and stirred for 5 hours. After the completion of the reaction, column chromatography was performed using MC/hexane as a developing solvent to obtain 1.0g of solid B-5 (yield: 57.34%).
(7) Synthesis of Compound 2(2-4(13, 13-dimethyl-13H-spiro [ benzo [ f, g ] indeno [1,2-b ] anthracene-7, 9' -fluoren ] -11-yl) phenyl-1, 4, 5-triphenyl-1H-imidazole)
1.00g (1.78mmol) of intermediate B-5, 1.07g (2.14mmol) of intermediate A-2, 1.23g (8.90mmol) of K2CO3And 0.06g (0.05mmol) of Pd (PPh)3)4Placed in a 250mL two-necked flask and dissolved in 80mL of a mixed solution of THF/water (3: 1). The reaction mixture was then refluxed and stirred for 12 hours. After completion of the reaction, column chromatography was performed using MC/hexane (3:1) as a developing solvent to obtain 0.7g of compound 2 as a solid (yield: 46.0%).
Synthesis example 2: synthesis of Compound 3
(1) Synthesis of intermediate C-1(4, 5-diphenyl-2- (4- (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborolan-2-yl) phenyl) thiazole)
3.30g (8.41mmol) of 2- (4-bromophenyl) -4, 5-diphenylthiazole, 6.41g (25.2 mmol)4mmol) of bis (pinacolato) diboron, 0.23g (0.25mmol) of Pd2(dba)30.24g (0.50mmol) of XPhos, 2.89g (29.44mmol) of KOAc were placed in a 500mL two-necked flask and dissolved in 80mL of 1, 4-dioxane. The reaction mixture was then refluxed and stirred for 12 hours. After completion of the reaction, column chromatography was performed using hexane/ethyl acetate (10:1) as a developing solvent to obtain 2.72g of C-1 as a solid (yield: 73.5%).
(2) Synthesis of Compound 3(2- (4- (13, 13-dimethyl-13H-spiro [ benzo [ f, g ] indeno [1,2-b ] anthracene-7, 9' -fluoren ] -11-yl) phenyl) -4, 5-diphenylthiazole)
1.00g (1.78mmol) of intermediate B-5, 0.94g (2.14mmol) of intermediate C-1, 1.23g (8.90mmol) of K2CO3And 0.06g (0.05mmol) of Pd (PPh)3)4Placed in a 250mL two-necked flask and dissolved in 80mL of a mixed solution of THF/water (3: 1). The reaction mixture was then refluxed and stirred for 12 hours. After completion of the reaction, column chromatography was performed using MC/hexane (2:1) as a developing solvent to obtain 1.0g of compound 3 as a solid (yield: 70.7%).
Synthesis example 3: synthesis of Compound 5
(1) Synthesis of intermediate E-2 (3-bromo-13, 13-dimethyl-13H-spiro [ benzo [ f, g ] indeno [1,2-b ] anthracene-7, 9' -fluorene ])
0.05g (1.04mmol) of Compound E-1 was placed in a 250mL two-necked flask, dissolved in 50mL chloroform, and 0.17g (0.055mmol) of bromine was slowly added to the flask. Then, the reaction mixture was stirred at room temperature for 24 hours. . After completion of the reaction, column chromatography was performed using MC/hexane (1:9) as a developing solvent to obtain 0.50g of the solid compound E-2 (yield: 85.9%).
(2) Synthesis of Compound 5(2- (4- (13, 13-dimethyl-13H-spiro [ benzo [ f, g ] indeno [1,2-b ] anthracene-7, 9' -fluorene ] 3-yl) phenyl) -1,4, 5-triphenyl-1H-imidazole
1.00g (1.78mmol) of intermediate B-5, 1.07g (2.14mmol) of intermediate A-2, 1.23g (8.90mmol) of K2CO3And 0.06g (0.05mmol) of Pd (PPh)3)4Placed in a 250mL two-necked flask and dissolved in 80mL of a mixed solution of THF/water (3: 1). The reaction mixture was then refluxed and stirred for 12 hours. After completion of the reaction, column chromatography was performed using MC/hexane (2:1) as a developing solvent to obtain 1.3g of compound 5 as a solid (yield: 85.5%).
Synthesis example 4: synthesis of Compound 6
Synthesis of Compound 6(2- (4- (13, 13-dimethyl-13H-spiro [ benzo ] [ f, g ] indeno [1,2-b ] anthracene-7, 9' -fluorene) phenyl) -4, 5-diphenylthiazole
1.15g (2.05mmol) of intermediate E-2, 1.08g (2.46mmol) of intermediate C-1, 1.42g (10.24mmol) of K2CO3And 0.07g (0.06mmol) of Pd (PPh)3)4Placed in a 250mL two-necked flask and dissolved in 120mL of a mixed solution of THF/water (3: 1). The reaction mixture was then refluxed and stirred for 12 hours. After completion of the reaction, column chromatography was performed using MC/hexane (1:1) as a developing solvent to obtain 1.2g of compound 6 as a solid (yield: 73.7%).
Synthesis example 5: synthesis of Compound 7
Synthesis of compound 7(N, N,13 '-triphenyl-13' H-spiro [ fluorene-9, 7 '-phenalene [1,2-b ] carbazole ] -10' -amine
1.2g (1.97mmol) of Compound I-1, 0.40g (2.36mmol) of diphenylamine, 0.05g (0.06mmol) of Pd2(dba)3、0.01g(0.06mmol)of P(t-Bu)3(tri-tert-butylphosphine), 0.57g (5.90mmol) of NatBuO (sodium tert-butoxide) was placed in a 250mL two-necked flask and dissolved in 100mL of toluene. The reaction mixture was then refluxed and stirred for 12 hours. After completion of the reaction, column chromatography was performed using MC/hexane (3:7) as a developing solvent to obtain 0.7g of compound 7 as a solid (yield: 51.0%).
Synthesis example 6: synthesis of Compound 8
Synthesis of compound 8(13 '-phenyl-10' - (4- (1,4, 5-triphenyl-1H-imidazol-2-yl) phenyl) -13 'H-spiro [ fluorene-9, 7' -phenalene [1,2-b ] carbazole
1.10g (1.80mmol) of Compound I-1, 1.08g (2.16mmol) of intermediate A-2, 1.25g (9.01mmol) of K2CO3And 0.06g (0.05mmol) of Pd (PPh)3)4Placed in a 250mL two-necked flask and dissolved in 80mL of a mixed solution of THF/water (3: 1). The reaction mixture was then refluxed and stirred for 12 hours. After completion of the reaction, column chromatography was performed using MC/hexane (3:7) as a developing solvent to obtain 1.00g of compound 8 as a solid (yield: 65.1%).
Synthesis example 7: synthesis of Compound 13
Synthesis of compound 13(N, N-diphenylspiro [ benzo [8,9] anthracene [2,3-b ] benzofuran-7, 9' -fluorene ] -11-amine
1.5g (2.80mmol) of Compound K-1, 0.57g (3.36mmol) of diphenylamine, 0.08g (0.08mmol) of Pd2(dba)3, 0.02g (0.08mmol) of P (t-Bu)3And 0.81g (8.40mmol) of NatBuO in a 250mL two-necked flask and dissolved in 100mL of toluene. The reaction mixture was then refluxed and stirred for 12 hours. After completion of the reaction, column chromatography was performed using MC/hexane (3:7) as a developing solvent to obtain 1.2g of compound 13 as a solid (yield: 62.3%).
Synthesis example 8: synthesis of Compound 19
Synthesis of compound 19(N, N,13 '-triphenyl-13' H-spiro [ fluorene-9, 7 '-phenalene [1,2-b ] carbazole ] -10' -amine
1.1g (1.99mmol) of the compound L-1, 0.41g (2.30mmol) of diphenylamine, 0.05g (0.06mmol) of Pd2(dba)3, 0.01g (0.06mmol) of P (t-Bu)3And 0.58g (5.98mmol) of NatBuO in a 250mL two-necked flask and dissolved in 100mL of toluene. The reaction mixture was then refluxed and stirred for 12 hours. After completion of the reaction, column chromatography was performed using MC/hexane (3:7) as a developing solvent to obtain 0.8g of compound 19 as a solid (yield: 58.3%).
Test example 1: FWHM measurement of organic compounds
FWHM (full width at half maximum) of compound 2, compound 3, compound 5, compound 6, compound 7 and compound 8 synthesized in synthesis examples 1 to 6, respectively, was measured. In addition, the FWHM of the delayed fluorescent material (i.e., 4CzIPN) was measured for comparison. The measurement results are shown in table 1 below. As shown in table 1, all the organic compounds synthesized in the synthesis examples had narrower FWHM than 4CzIPN, which is expected to enhance the color purity.
Table 1: luminescence FWHM of organic compounds
Sample (I)
FWHM(nm)
4CzIPN
85
Compound 2
54
Compound 3
51
Compound 5
65
Compound 6
70
Compound 7
71
Compound 8
68
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