TW201410844A - Organic electroluminescent element, and compound, carrier-transporting material and host material used therein - Google Patents

Abstract

The purpose of the present invention is to provide an organic electroluminescent element having high luminous efficiency. The organic electroluminescent element is characterized in that a compound represented by general formula (1) is used. In general formula (1), R1 to R8 and R11 to R20 independently represent a hydrogen atom or a substituent.

Description

Organic electroluminescent element and compound therefor, carrier transport material and host material

The present invention relates to an organic electroluminescent device having high luminous efficiency. Further, the present invention relates to a compound for a organic electroluminescence element, a carrier transport material and a host material.

The industry is actively researching to improve the luminous efficiency of organic electroluminescent elements (organic EL elements). In the past, various efforts have been made to improve the luminous efficiency by newly combining an electron transporting material, a hole transporting material, a host material, a light-emitting material, and the like which constitute an organic electroluminescence device. Among them, the phosphorescent material can use an excited triplet state and has high quantum efficiency, and thus has attracted attention as a light-emitting material. However, since the phosphorescent material has a common problem that the triplet-triplet state is likely to be deactivated, various studies have been conducted to suppress such deactivation (see Non-Patent Document 1).

For example, a compound containing a triphenylphosphine oxide structure has a higher lowest excited triplet energy level than a conventional carbazole compound, and thus has been attracting attention as a host material of a light-emitting material. For example, Patent Document 1 discloses that the luminous efficiency is improved by selectively using a compound having a lowest excitation triplet energy level of 2.65 eV or more. Patent Document 1 discloses an organic electroluminescence device having a compound having a structure in which a luminescent material is doped. Light-emitting layer.

Non-Patent Document 2 discloses an organic electroluminescence device having a compound containing a triphenylphosphine oxide structure and doped with bis(4,6-difluorophenylpyridine-N,C ² )pyridine. A luminescent layer of fluorene (III) (Flrpic). Phosphorescence spectra measured using a dilute solution are disclosed in this document.

Non-Patent Document 3 discloses an organic electroluminescence device having a compound containing a triphenylphosphine oxide structure and doped with bis(4,6-difluorophenylpyridine-N,C ² )pyridine. A luminescent layer of fluorene (III) (Flrpic). According to this document, according to the organic electroluminescence device having such a structure, luminous efficiency can be improved.

On the other hand, there has also been proposed a host material comprising a compound having a donor site and a receptor site in a molecule different from the compounds, and for example, it is proposed in Non-Patent Document 4 to have a carbazole structure in a molecule. The following compounds of the triphenylphosphine oxide structure. Further, Patent Document 2 discloses an organic electroluminescence device having a derivative in which a phenyl group or a third butyl group is introduced at the 3-position and the 6-position of the carbazole group of the compound as a host material, and is doped. There is a luminescent layer of bis(4,6-difluorophenylpyridine-N,C ² )pyridinium ruthenium (III) (Flrpic).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] International Publication WO2006/130353

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2010-184910

[Non-patent literature]

[Non-Patent Document 1] L. Xiao, Adv. Mater. 2011, 23, 926-952

[Non-Patent Document 2] P. A. Vecchi et. al., Organic Letters, 2006, Vol. 8, No. 19, 4211-4214

[Non-Patent Document 3] C. Han, Chem. Eur. J. 2011, 17, 5800-5803

[Non-Patent Document 4] F. Phys. Chem. C2008, 112, 7989-7996

The present inventors have conducted various tests for the host material having both the donor site and the receptor site in the molecule, and as a result, it is clear that even a compound having a structure as described in Non-Patent Document 4 in the molecule is used as a host material. In the manufacture of organic electroluminescent elements, sufficient luminous efficiency cannot be achieved. Further, even if a derivative having a substituent introduced into a compound having the same skeleton is used, the improvement in luminous efficiency is limited. Therefore, the present inventors have made efforts to develop a useful organic electroluminescence device by developing a material having a new skeleton capable of achieving high luminous efficiency.

The inventors of the present invention have diligently studied to solve the above problems, and as a result, have found that a structure obtained by directly connecting a donor site and a receptor site can achieve the object. That is, the inventors of the present invention have provided the following invention as means for solving the above problems.

[1] An organic electroluminescence device using a compound represented by the following formula (1).

[In the formula (1), R ¹ to R ⁸ and R ¹¹ to R ²⁰ each independently represent a hydrogen atom or a substituent; R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁵ and R ⁶ , R ⁶ and R ⁷ , R ⁷ and R ⁸ , R ¹¹ and R ¹² , R ¹² and R ¹³ , R ¹³ and R ¹⁴ , R ¹⁴ and R ¹⁵ , R ¹⁶ and R ¹⁷ , R ¹⁷ and R ¹⁸ R ¹⁸ and R ¹⁹ , R ¹⁹ and R ²⁰ may be bonded to each other to form a cyclic structure].

[2] The organic electroluminescence device according to [1], which has a light-emitting layer comprising a compound represented by the above formula (1) and a light-emitting material.

[3] The organic electroluminescence device according to [2], wherein the luminescent material is a phosphorescent material.

[4] The organic electroluminescence device according to [3], wherein the luminescent material is an Ir complex, a Cu complex or a Pt complex.

[5] The organic electroluminescence device according to [2], wherein the luminescent material is a delayed fluorescent material.

[6] The organic electroluminescence device according to any one of [2] to [5] wherein the luminescent material has a maximum emission wavelength of 450 to 485 nm.

[7] The organic electroluminescence device according to any one of [1] to [6] wherein R ¹ to R ⁸ in the above formula (1) are each independently a hydrogen atom, substituted or not Substituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or substituted Unsubstituted alkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted heteroaryloxy, cyano, substituted or unsubstituted amine, substituted or unsubstituted Carbazolyl, nitro, substituted or unsubstituted fluorenyl, substituted or unsubstituted alkoxycarbonyl, substituted or unsubstituted alkylsulfonyl, hydroxy, substituted or unsubstituted Alkyl guanamine, or a substituted or unsubstituted trialkylalkylene group.

[8] The organic electroluminescence device according to any one of [1] to [7] wherein R ¹¹ to R ²⁰ in the above formula (1) are each independently a hydrogen atom, substituted or not Substituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or substituted Unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, or substituted or unsubstituted heteroaryloxy group.

[9] The organic electroluminescence device according to any one of [1] to [6] wherein R ¹ to R ⁸ and R ¹¹ to R ²⁰ in the above formula (1) are each independently hydrogen. Atom, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted aryloxy.

[10] The organic electroluminescence device according to any one of [1] to [9], wherein the compound represented by the above formula (1) has a structure represented by the following formula (2).

[In the formula (2), R ² , R ³ , R ⁶ , R ⁷ , R ¹² to R ¹⁴ and R ¹⁷ to R ¹⁹ each independently represent a hydrogen atom or a substituent; R ² and R ³ , R ⁶ and R ⁷ , R ¹² and R ¹³ , R ¹³ and R ¹⁴ , R ¹⁷ and R ¹⁸ , and R ¹⁸ and R ¹⁹ may be bonded to each other to form a cyclic structure].

[11] A compound represented by the above formula (1) (wherein at least one of R ¹ to R ⁸ and R ¹¹ to R ²⁰ is a substituent).

[12] A carrier transporting material comprising the compound represented by the above formula (1).

[13] A host material comprising the compound represented by the above formula (1).

The compound represented by the formula (1) is useful as a carrier transport material, and is also useful as a host material of the light-emitting layer. Since the organic electroluminescence device of the present invention uses a compound having a specific structure, it has a feature of high luminous efficiency.

1‧‧‧Substrate

2‧‧‧Anode

3‧‧‧ hole injection layer

4‧‧‧ hole transport layer

5‧‧‧Lighting layer

6‧‧‧Electronic transport layer

7‧‧‧ cathode

Fig. 1 is an emission spectrum of an organic electroluminescence device of Example 1.

2 is a graph showing current density-voltage characteristics of the organic electroluminescent elements of Example 1 and Comparative Example 1.

Fig. 3 is a graph showing the luminous intensity-voltage characteristics of the organic electroluminescent elements of Example 1 and Comparative Example 1.

4 is a graph showing current density-external quantum efficiency characteristics of the organic electroluminescent elements of Example 1 and Comparative Example 1. FIG.

Fig. 5 is an emission spectrum of the organic photoluminescence device of Example 2 and the organic electroluminescence device of Example 3.

Fig. 6 is a time-resolved spectrum of the organic photoluminescent element of Example 2.

Fig. 7 is a graph showing current density-voltage characteristics of the organic electroluminescence device of Example 3.

Fig. 8 is a graph showing the luminous intensity-voltage characteristics of the organic electroluminescence device of Example 3.

Fig. 9 is a graph showing current density-external quantum efficiency characteristics of the organic electroluminescence device of Example 3.

Fig. 10 is an emission spectrum of the organic electroluminescence device of Example 4.

Fig. 11 is a graph showing current density-voltage-emission intensity characteristics of the organic electroluminescence device of Example 4.

Figure 12 is a graph showing the current density of the organic electroluminescent device of Example 4 - external quantum effect A chart of rate characteristics.

Figure 13 is an emission spectrum of the organic electroluminescence device of Example 5.

Fig. 14 is a graph showing current density-voltage-emission intensity characteristics of the organic electroluminescence device of Example 5.

Fig. 15 is a graph showing current density-external quantum efficiency characteristics of the organic electroluminescence device of Example 5.

Fig. 16 is a schematic cross-sectional view showing a layer configuration of an organic electroluminescence device.

Hereinafter, the contents of the present invention will be described in detail. The description of the constituent elements described below is based on representative embodiments or specific examples of the present invention, but the present invention is not limited to such embodiments or specific examples. In addition, the numerical range represented by the "~" in this specification means the range which contains the numerical value of the [~~.

[Compound represented by the formula (1)]

The organic electroluminescence device of the present invention is characterized in that it uses a compound represented by the following formula (1).

[Chem. 7] Formula (1)

In the formula (1), R ¹ to R ⁸ and R ¹¹ to R ²⁰ each independently represent a hydrogen atom or a substituent. R ¹ to R ⁸ and R ¹¹ to R ²⁰ may each be a hydrogen atom, or one or more substituents may be used. When two or more substituents are used, the mutually different ones may be the same or different.

The substituent which may be employed as R ¹ to R ⁸ may, for example, be a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, substituted or unsubstituted. Substituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted heteroaryloxy , cyano, substituted or unsubstituted amino, substituted or unsubstituted carbazolyl, nitro, substituted or unsubstituted fluorenyl, substituted or unsubstituted alkoxycarbonyl, Substituted or unsubstituted alkyl sulfonyl, hydroxy, substituted or unsubstituted alkyl decyl, substituted or unsubstituted trialkyl decyl. More specifically, examples of the substituent which may be employed as R ¹ to R ⁸ include a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and a substituted or unsubstituted aromatic group having 7 to 20 carbon atoms. Alkyl, substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 30 carbon atoms a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms. a substituted or unsubstituted heteroaryloxy group having 3 to 30 carbon atoms, a cyano group, a substituted or unsubstituted dialkylamino group having 2 to 20 carbon atoms, and a substituted carbon number of 12 to 30 Or unsubstituted diarylamine group, substituted or unsubstituted carbazolyl group having 12 to 30 carbon atoms, substituted or unsubstituted diarylalkylamino group having 12 to 30 carbon atoms, amine group a nitro group, a substituted or unsubstituted fluorenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkoxycarbonyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted carbon number of 1 to 20. Alkylsulfonyl, hydroxy, decylamino, substituted or unsubstituted carbon number 1~10 Substituted haloalkyl group, substituted or unsubstituted alkyl decylamino group having 2 to 10 carbon atoms, substituted or unsubstituted trialkylalkylene group having 3 to 20 carbon atoms, carbon number 4 to 20 a substituted or unsubstituted trialkylsilylalkyl group, a substituted or unsubstituted trialkyldecylalkylene group having 5 to 20 carbon atoms, a substituted or unsubstituted carbon number of 5-20 An alkyl decyl alkynyl group, which may in turn be substituted with a substituent. R ¹ to R ^{8 are more} preferably a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a carbon number of 3 Substituted or unsubstituted heteroaryl group of ~30, substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, carbon number a substituted or unsubstituted heteroaryloxy group of 3 to 30, a substituted or unsubstituted diarylamino group having 12 to 30 carbon atoms, and an oxazolyl group having 12 to 30 carbon atoms.

In the formula (1), as the substituent which may be employed as R ¹¹ to R ²⁰ , for example, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted group may be mentioned. Alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, substituted or Unsubstituted heteroaryloxy group. More specifically, as the substituent which may be employed as R ¹¹ to R ²⁰ , a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group having 7 to 20 carbon atoms may be mentioned. Alkyl, substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 30 carbon atoms a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms. A substituted or unsubstituted heteroaryloxy group having 3 to 30 carbon atoms, which may be further substituted with a substituent. R ¹ to R ^{8 are more} preferably a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a carbon number of 3 Substituted or unsubstituted heteroaryl group of ~30, substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, carbon number a substituted or unsubstituted heteroaryloxy group of 3 to 30.

The alkyl group referred to in the present specification may be any of a linear chain, a branched chain, and a cyclic group, more preferably a carbon number of 1 to 6, and specific examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group. Base, tert-butyl, pentyl, hexyl, isopropyl. The aryl group may be a monocyclic ring or a fused ring, and specific examples thereof include a phenyl group and a naphthyl group. The alkoxy group may be any of a linear chain, a branched chain, and a cyclic group, and more preferably has a carbon number of 1 to 6, and specific examples thereof include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. , a third butoxy group, a pentyloxy group, a hexyloxy group, an isopropoxy group. The two alkyl groups of the dialkylamino group may be the same or different from each other, but are preferably the same. The two alkyl groups of the dialkylamino group may each independently be linear, branched or cyclic, and more preferably have a carbon number of 1 to 6. Specific examples include methyl group and ethyl group. Base, propyl, butyl, pentyl, hexyl, isopropyl. The aryl group may be a monocyclic ring or a fused ring, and specific examples thereof include a phenyl group and a naphthyl group. The heteroaryl group may be a single ring or a fused ring, and specific examples thereof include a pyridyl group and a fluorene group. Base, pyrimidinyl, three Base, triazolyl, benzotriazolyl. The heteroaryl group may be a group bonded via a hetero atom or a group bonded via a carbon atom constituting the heteroaryl ring.

In the above formula (1), R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁵ and R ⁶ , R ⁶ and R ⁷ , R ⁷ and R ⁸ , R ¹¹ and R ¹² R ¹² and R ¹³ , R ¹³ and R ¹⁴ , R ¹⁴ and R ¹⁵ , R ¹⁶ and R ¹⁷ , R ¹⁷ and R ¹⁸ , R ¹⁸ and R ¹⁹ , R ¹⁹ and R ²⁰ may be bonded to each other, respectively. Ring structure. The cyclic structure referred to herein may be an aromatic ring or an aliphatic ring, or may be a hetero atom. The hetero atom referred to herein is preferably selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom. Examples of the cyclic structure to be formed include a benzene ring, a naphthalene ring, a pyridine ring, and an anthracene. Ring, pyrimidine ring, pyridyl Ring, pyrrole ring, imidazole ring, pyrazole ring, triazole ring, imidazoline ring, Oxazole ring, different An azole ring, a thiazole ring, an isothiazole ring, a cyclohexadiene ring, a cyclohexene ring, a cyclopentene ring, a cycloheptatriene ring, a cycloheptadiene ring, a cycloheptene ring or the like. In the case of forming a cyclic structure, R ² and R ³ , R ³ and R ⁴ , R ⁵ and R ⁶ , R ⁶ and R ⁷ , R ¹² and R ¹³ , R ¹³ of the formula (1) are preferred. At least one of R ¹⁴ , R ¹⁷ and R ¹⁸ , R ¹⁸ and R ¹⁹ is bonded to each other to form a cyclic structure.

As a preferred compound group represented by the formula (1), R ¹ to R ⁸ and R ¹¹ to R ²⁰ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, substituted or unsubstituted. A group of compounds having an alkoxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryloxy group. Further, as another preferred compound group represented by the formula (1), R ¹ to R ⁸ and R ¹¹ to R ²⁰ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, and A group of compounds of substituted or unsubstituted aryl groups.

The compound represented by the formula (1) is preferably a compound having a structure represented by the following formula (2).

In the formula (2), R ² , R ³ , R ⁶ , R ⁷ , R ¹² to R ¹⁴ and R ¹⁷ to R ¹⁹ each independently represent a hydrogen atom or a substituent. For the examples and preferred ranges of the substituents referred to herein, reference may be made to the corresponding description of the above formula (1).

In the formula (2), R ² and R ³ , R ⁶ and R ⁷ , R ¹² and R ¹³ , R ¹³ and R ¹⁴ , R ¹⁷ and R ¹⁸ , R ¹⁸ and R ¹⁹ may be bonded to each other, respectively. Form a ring structure. For the examples and preferred ranges of the cyclic structures, reference may be made to the corresponding description of the above formula (1).

As a state of the compound represented by the general formula (2), a compound group in which R ² and R ⁷ are a hydrogen atom and R ³ and R ⁶ are a substituent; R ³ and R ⁶ are a hydrogen atom and are preferably exemplified; a compound group in which R ² and R ⁷ are a substituent; a compound group in which R ¹³ and R ¹⁸ are a hydrogen atom and R ¹² , R ¹⁴ , R ¹⁷ and R ¹⁹ are a substituent; R ¹² , R ¹⁴ , R ¹⁷ and R ¹⁹ A group of compounds which are hydrogen atoms and in which R ¹³ and R ¹⁸ are a substituent.

Specific examples of the compound represented by the formula (1) are exemplified below, but the compound represented by the formula (1) which can be used in the present invention should not be construed as being limited by the specific examples. Further, in the structural formula of the following specific examples, t-Bu represents a third butyl group.

[Synthesis method of compound represented by general formula (1)]

In the compound represented by the formula (1), a compound in which at least one of R ¹ to R ⁸ and R ¹¹ to R ²⁰ is a substituent is a novel compound. These novel compounds have a relatively high glass transition temperature (Tg) and are easy to form an amorphous film. These novel compounds can be synthesized by combining known reactions. For example, a compound represented by the formula (1) can be synthesized by coupling a carbazole with diphenylphosphine chloride and converting the obtained compound into a phosphine oxide according to the following scheme. The coupling reaction of carbazole with diphenylphosphine chloride is a known coupling reaction which can be carried out using n-butyllithium. Further, a reaction for converting the obtained compound into phosphine oxide is also known, and conversion can be carried out using hydrogen peroxide. The specific conditions for these reactions can be referred to the following synthesis examples. Further, the compound represented by the formula (1) can also be synthesized by combining other known synthesis reactions.

[Chemistry 9]

[Organic Electroluminescent Element]

The compound represented by the formula (1) is useful as a material constituting the organic electroluminescence device. In particular, the compound represented by the formula (1) is useful as a carrier transport material, and is also useful as a host material of the light-emitting layer. The organic electroluminescence element using the compound represented by the general formula (1) can improve the luminous efficiency.

The organic electroluminescent element has a structure in which at least an anode, a cathode, and an organic layer between the anode and the cathode are formed. The organic layer contains at least a light-emitting layer, and may be composed only of a light-emitting layer, or may have one or more organic layers in addition to the light-emitting layer. Examples of such other organic layers include a hole transport layer, a hole injection layer, an electron blocking layer, a hole blocking layer, an electron injecting layer, an electron transporting layer, and an exciton blocking layer. The hole transport layer may also be a hole injection transport layer having a hole injection function, and the electron transport layer may also be an electron injection transport layer having an electron injection function. A configuration of a specific organic electroluminescence device is shown in Fig. 16. In Fig. 16, 1 denotes a substrate, 2 denotes an anode, 3 denotes a hole injection layer, 4 denotes a hole transport layer, 5 denotes a light-emitting layer, 6 denotes an electron transport layer, and 7 denotes a cathode. Following, the composition Description of the pieces or layers.

(anode)

As the anode of the organic electroluminescence device, a metal having a large work function (4 eV or more), an alloy, a conductive compound, and a mixture thereof are preferably used as the electrode material. Specific examples of such an electrode material include a conductive transparent material such as a metal such as Au, CuI, indium tin oxide (ITO), SnO ₂ or ZnO. Further, a material which is amorphous and can be made into a transparent conductive film such as IDIXO (In ₂ O ₃ -ZnO) can also be used. In the anode system, the electrode materials can be formed into a thin film by vapor deposition or sputtering, and a pattern of a desired shape can be formed by photolithography, or when pattern precision is not required (about 100 μm or more). A pattern is formed through a mask of a desired shape during vapor deposition or sputtering of the electrode material. Alternatively, in the case of using a material which can be applied as an organic conductive compound, a wet film formation method such as a printing method or a coating method can also be used. In the case where light is extracted from the anode, it is preferable that the transmittance is more than 10%, and the sheet resistance as the anode is preferably several hundred Ω/□ or less. Further, the film thickness varies depending on the material, and is usually selected from the range of 10 to 1000 nm, preferably 10 to 200 nm.

(cathode)

On the other hand, as the cathode, a metal having a small work function (4 eV or less) (referred to as an electron injecting metal), an alloy, a conductive compound, and a mixture thereof are used as the electrode material. Specific examples of such an electrode material include sodium, sodium-potassium alloy, magnesium, lithium, magnesium/copper mixture, magnesium/silver mixture, magnesium/aluminum mixture, magnesium/indium mixture, and aluminum/aluminum oxide (Al _{2 ).} O ₃ ) a mixture, indium, a lithium/aluminum mixture, a rare earth metal, or the like. Among these, in terms of electron injectability and durability against oxidation or the like, a mixture of an electron injecting metal and a second metal having a work function value larger than a stable metal such as a magnesium/silver mixture is preferable. , magnesium/aluminum mixture, magnesium/indium mixture, aluminum/alumina (Al ₂ O ₃ ) mixture, lithium/aluminum mixture, aluminum, and the like. The cathode system can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. Further, the sheet resistance as the cathode is preferably several hundred Ω/□ or less, and the film thickness is usually selected from the range of 10 nm to 5 μm, preferably 50 to 200 nm. Further, since the emitted light is transmitted, if either one of the anode and the cathode of the organic electroluminescent element is transparent or translucent, the luminance of the light is improved, which is preferable.

Further, by using a conductive transparent material exemplified in the description of the anode for the cathode, a transparent or translucent cathode can be produced, and by using it, an element having both the anode and the cathode can be made transparent.

(lighting layer)

The light-emitting layer is a layer that emits light after exciton is generated by recombination of holes and electrons injected from the anode and the cathode, respectively, and preferably includes a light-emitting material and a host material. As the host material, it is preferred to use one or more selected from the group of compounds of the present invention represented by the formula (1). In order for the organic electroluminescent device of the present invention to exhibit high luminous efficiency, it is important to enclose the singlet excitons and triplet excitons generated in the luminescent material in the luminescent material. Therefore, it is preferred to use a host material represented by the general formula (1) in addition to the luminescent material in the light-emitting layer. When the host material is used, the content of the luminescent material in the light-emitting layer is preferably 0.1% by weight or more, more preferably 1% by weight or more, still more preferably 50% by weight or less, still more preferably 20% by weight or less. Further, it is preferably 10% by weight or less.

The luminescent material used in the organic electroluminescence device of the present invention can be selected in consideration of the wavelength at which light emission is desired or the like. In the present invention, in particular, a blue luminescent material having a maximum luminescent wavelength of 450 to 485 nm of the luminescent material can be preferably selected. The maximum luminescent wavelength of the blue luminescent material is preferably 455 to 480 nm.

As the light-emitting material used in the organic electroluminescence device of the present invention, for example, a phosphorescent material, a delayed fluorescent material, an excited composite type light-emitting material, or the like can be appropriately selected and used.

As the phosphorescent material, various previously known metal complex compounds can be mentioned. In particular, a material that emits deep blue phosphorescence is preferably selected in the present invention. Examples of the phosphorescent material include, for example, Flrpic, FCNIr, Ir(dbfmi), FIr6, Ir(fbppz) ₂ (dfbdp), and Irr compound such as FIrN4; or [Cu(dnbp) disclosed below). (DPEPhos)]BF ₄ , or [Cu(dppb)(DPEPhos)]BF ₄ ,[Cu(μ-l)dppb] ₂ ,[Cu(μ-Cl)DPEphos] ₂ ,Cu(2-tzq)(DPEPhos Cu complexes such as [Cu(PNP)] ₂ , compound 1001, Cu(Bpz ₄ ) (DPEPhos); Pt complexes such as FPt and Pt-4. The structures of these are shown below.

[11]

[化12]

Although a representative phosphorescent material is described above, the phosphorescent material usable in the present invention is not limited thereto. The main luminescent materials are described, for example, in Chapter 9 of the "Organic EL Device Physics, Materials Chemistry, and Device Applications" published by CMC.

As the retardation fluorescent material, for example, a thermally activated delayed fluorescent material such as PIC-TRZ or [Cu(PNP- ^t Bu)] ₂ described below can be exemplified.

Further, a delayed fluorescent material represented by the following formula (10) can also be preferably exemplified.

General formula (10)

In [the general formula ^{(10), R 101 ~ R} 105 in the at least one represents a cyano group, and R ¹⁰¹ ~ R ¹⁰⁵ in the at least one group represented by the following general formula (11) represents the remaining of R ¹⁰¹ to R ¹⁰⁵ represent a hydrogen atom or a substituent].

[In the formula (11), R ²¹ to R ²⁸ each independently represent a hydrogen atom or a substituent. Among them, at least one of the following <A> or <B> is satisfied.

<A> R ²⁵ and R ²⁶ together form a single bond.

<B> R ²⁷ and R ²⁸ together represent the atomic group required to form a substituted or unsubstituted benzene ring.

The group represented by the formula (11) is preferably a group represented by any one of the following formulas (12) to (15). Among them, a group represented by the formula (12) is preferred.

[Chemistry 16]

[In the formula (12), R ³¹ to R ³⁸ each independently represent a hydrogen atom or a substituent].

[In the formula (13), R ⁴¹ to R ⁴⁶ each independently represent a hydrogen atom or a substituent].

[Chem. 18] Formula (14)

[In the formula (14), R ⁵¹ to R ⁶² each independently represent a hydrogen atom or a substituent].

[In the formula (15), R ⁷¹ to R ⁸⁰ each independently represent a hydrogen atom or a substituent].

Examples of the substituent in the general formulae (11) to (15) include a hydroxyl group, a halogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a carbon number of 1 to 2. 20 alkylthio group, alkyl group substituted with 1 to 20 carbon atoms, fluorenyl group having 2 to 20 carbon atoms, aryl group having 6 to 40 carbon atoms, heteroaryl group having 3 to 40 carbon atoms, carbon number 12~ 40 bis arylamine group, carbon number 12~40 Substituted or unsubstituted carbazolyl, alkenyl group having 2 to 10 carbon atoms, alkynyl group having 2 to 10 carbon atoms, alkoxycarbonyl group having 2 to 10 carbon atoms, alkylsulfonyl group having 1 to 10 carbon atoms Base, haloalkyl group having 1 to 10 carbon atoms, decylamino group, alkyl guanamine group having 2 to 10 carbon atoms, trialkylsulfonyl group having 3 to 20 carbon atoms, and trialkyl decane having 4 to 20 carbon atoms An alkyl group, a trialkylsulfonylalkenyl group having 5 to 20 carbon atoms, a trialkylsulfonylalkynyl group having 5 to 20 carbon atoms, and a nitro group. In these specific examples, those which may be substituted with a substituent may be substituted. More preferred substituents are a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a substituted or unsubstituted carbon number of 6 to 40. An aryl group, a substituted or unsubstituted heteroaryl group having 3 to 40 carbon atoms, a substituted or unsubstituted diarylamino group having 12 to 40 carbon atoms, or a substituted or unsubstituted carbon number of 12 to 40 Substituted carbazolyl. Further preferred substituents are a fluorine atom, a chlorine atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, and a carbon number. a substituted or unsubstituted dialkylamino group of 1 to 10, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms.

(10) In the compounds represented, as a preferred group of compounds exemplified by the following general formula: R ¹⁰¹ ~ R ¹⁰⁵ in at least one of a cyano group, and R ¹⁰¹ ~ R ¹⁰⁵ in the least by a substituted 3 Or unsubstituted 9-oxazolyl, substituted or unsubstituted 1,2,3,4-tetrahydro-9-carbazolyl, substituted or unsubstituted 1-indenyl, or The substituted or unsubstituted diarylamine group, the remaining R ¹⁰¹ to R ¹⁰⁵ are a hydroxyl group.

Among the compounds represented by the formula (10), as a further preferred compound group, one of R ¹⁰¹ to R ¹⁰⁵ is a cyano group, and two of R ¹⁰¹ to R ¹⁰⁵ are substituted or Unsubstituted 9-carbazolyl, the other two are hydrogen atoms.

Examples of the excitation complex type luminescent material which can be used in the light-emitting layer of the organic electroluminescence device of the present invention include m-MTDATA (4, 4', 4"-Tris (N-3-methylphenyl-N) described below. -phenylamino)triphenylamine, 4,4',4"-tris(N-3-methylphenyl-N-phenylamino)triphenylamine) and PBD(2-(4-biphenyl)-5-(4- Tert-butylphenyl)- 1,3,4-oxadiazole,2-(4-biphenyl)-5-(4-t-butylphenyl)-1,3,4- Diazole), PyPySPyPy(2,5-bis-(2,2-bipyridine-6-yl)-1,1-dimethyl-3,4-diphenyl silacyclopentadiene, 2,5-bis-(2,2-bipyridine -6-yl)-1,1-dimethyl-3,4-diphenylfluorene heterocycle) and NPB (4,4'-bis[N-(1-naphthyl)-N-phenylamino] Biphenyl,4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl), PPSPP(2,5-di-(3-biphenyl)-1,1-dimethyl-3 4-diphenyl silacyclopentadiene, 2,5-di-(3-biphenyl)-1,1-dimethyl-3,4-diphenylfluorene heterocycle) and NPB are preferred examples.

(injection layer)

The injection layer is a layer disposed between the electrode and the organic layer in order to reduce the driving voltage or increase the luminance of the light, and has a hole injection layer and an electron injection layer, and may exist between the anode and the light-emitting layer or the hole transport layer. And between the cathode and the light-emitting layer or the electron transport layer. The injection layer can be set as needed.

(barrier layer)

The barrier layer prevents the charge (electrons or holes) present in the light-emitting layer and/or the layer of excitons diffusing out of the light-emitting layer. The electron blocking layer may be disposed between the light emitting layer and the hole transport layer to prevent electrons from passing through the light emitting layer toward the hole transport layer. Similarly, the hole blocking layer may be disposed between the light emitting layer and the electron transporting layer to prevent the holes from passing through the light emitting layer toward the electron transporting layer. Also, a barrier layer may be used to prevent excitons from diffusing to the outside of the light-emitting layer. That is, the electron blocking layer and the hole blocking layer may each function as an exciton blocking layer. The electron blocking layer or the exciton blocking layer referred to in the present specification is used in the sense of a layer containing a function of an electron blocking layer and an exciton blocking layer in one layer.

(hole blocking layer)

The hole blocking layer has a function of an electron transport layer in a broad sense. The hole blocking layer has the function of transporting electrons and blocking the holes from reaching the electron transport layer, thereby increasing the probability of recombination of electrons and holes in the light-emitting layer. As the material of the hole blocking layer, the material of the electron transport layer described below may be used as needed.

(electronic barrier layer)

The so-called electron blocking layer has a function of transporting holes in a broad sense. The electron blocking layer has a function of transporting holes and blocking electrons from reaching the hole transport layer, thereby increasing the probability of recombination of electrons and holes in the light-emitting layer.

(exciton blocking layer)

The exciton blocking layer is used to block the diffusion of excitons generated by recombination of holes and electrons in the light-emitting layer to the charge transport layer, and can be efficiently inserted by the insertion of the layer. The excitons are enclosed in the luminescent layer and can improve the luminous efficiency of the element. The exciton blocking layer may be inserted on either the anode side or the cathode side adjacent to the light emitting layer, or may be simultaneously inserted on both sides. That is, in the case where the exciton blocking layer is provided on the anode side, the layer may be inserted adjacent to the light-emitting layer between the hole transport layer and the light-emitting layer, and may be applied to the light-emitting layer and the cathode when inserted on the cathode side. The layer is inserted between adjacent to the light-emitting layer. Further, between the anode and the exciton blocking layer adjacent to the anode side of the light-emitting layer, a hole injection layer or an electron blocking layer may be provided between the cathode and the exciton blocking layer adjacent to the cathode side of the light-emitting layer. There may be an electron injecting layer, an electron transporting layer, a hole blocking layer, and the like. When the barrier layer is disposed, at least one of the excited singlet energy and the excited triplet energy of the material used as the barrier layer is preferably higher than the excited singlet energy and the excited triplet energy of the luminescent material.

(hole transport layer)

The hole transport layer includes a hole transporting material having a function of transporting a hole, and the hole transport layer may be provided with a single layer or a plurality of layers.

The hole transporting material may be any one of an organic substance and an inorganic material, such as one having injection or transport of a hole and barrier properties of electrons. As a known hole transporting material which can be used, for example, a triazole derivative can be cited. Diazole derivatives, imidazole derivatives, carbazole derivatives, carbazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamines Derivatives, amine-substituted chalcone derivatives, An azole derivative, a styryl hydrazine derivative, an anthrone derivative, an anthracene derivative, an anthracene derivative, a decazane derivative, an aniline copolymer, and further, a conductive polymer oligomer, especially a thiophene oligomerization Preferably, a porphyrin compound, an aromatic tertiary amine compound, and a styrylamine compound are used, and an aromatic tertiary amine compound is more preferably used.

(electron transport layer)

The electron transport layer includes a material having a function of transporting electrons, and the electron transport layer may be provided with a single layer or a plurality of layers.

The electron transporting material (and sometimes also the hole blocking material) may have a function of transferring electrons injected from the cathode to the light emitting layer. Examples of the electron transporting layer which can be used include a nitro-substituted anthracene derivative, a biphenyl hydrazine derivative, a thiopyran dioxide derivative, a carbodiimide, a fluorenylene methane derivative, and a quinodimethane. And anthrone derivatives, Diazole derivatives and the like. Further, above Among the oxadiazole derivatives, A thiadiazole derivative in which an oxygen atom of a oxazolyl ring is substituted with a sulfur atom, and a quinine which is known as a pull electron group Quinone ring The porphyrin derivative can also be used as an electron transporting material. Further, a polymer material obtained by introducing the materials into a polymer chain or a polymer material in which the materials are a main chain of the polymer may be used.

When the organic electroluminescence device is produced, not only the compound represented by the formula (1) but also a layer other than the light-emitting layer can be used. In this case, the compound represented by the formula (1) used for the light-emitting layer may be the same as or different from the compound represented by the formula (1) used for the layer other than the light-emitting layer. For example, the compound represented by the formula (1) can also be used for the above-mentioned injection layer, barrier layer, hole barrier layer, electron blocking layer, exciton blocking layer, hole transport layer, electron transport layer and the like. The film forming method of the layers is not particularly limited, and it can be produced by either a dry process or a wet process.

The organic electroluminescence device produced by the above method emits light by applying an electric field between the anode and the cathode of the obtained device. At this time, if the light of the excitation singlet energy is used, it is confirmed that the light of the wavelength corresponding to the energy level is the fluorescent light emission and the delayed fluorescent light emission. Further, if the light emitted by the triplet energy is excited, it is confirmed that the wavelength corresponding to the energy level is phosphorescence. In general, the fluorescent lifetime of fluorescent light is shorter than that of delayed fluorescent light, so that the luminous lifetime can be distinguished by the use of fluorescent and delayed fluorescent light.

On the other hand, regarding phosphorescence, a usual organic compound such as the compound of the present invention is excited to be unstable in the triplet state and converted into heat, etc., and the life is short and immediately inactivated, so that it is hardly observed at room temperature. In order to measure the excited triplet energy of a usual organic compound, it can be measured by observing the luminescence under extremely low temperature conditions.

The organic electroluminescent device of the present invention can be applied to a single component, including a configuration array The elements of the columnar structure, the anode and the cathode are arranged in any one of X-Y matrix configurations. According to the present invention, an organic light-emitting element in which the light-emitting efficiency is greatly improved by including the compound represented by the general formula (1) in the light-emitting layer is obtained. The organic light-emitting element such as the organic electroluminescence device of the present invention can be further applied to various applications. For example, an organic electroluminescence display device can be manufactured by using the organic electroluminescence device of the present invention, and the details can be referred to "Ohsha", which is co-authored by Jing Shi, Anda Chiba, and Murata. Further, in particular, the organic electroluminescence device of the present invention can also be applied to an organic electroluminescence illumination or backlight device which is in great demand.

[Examples]

Hereinafter, the features of the present invention will be specifically described by way of examples. The materials, processing contents, processing procedures, and the like shown in the following examples can be appropriately changed without departing from the gist of the invention. Therefore, the scope of the invention should not be construed as limited by the specific examples shown below.

(Synthesis Example 1)

Compound 1 was synthesized according to the following procedure.

In a 100 mL two-necked flask, 3,6-di-t-butylcarbazole (0.97 g, 3.48 mmol) was charged and dried under vacuum. The flask was replaced with nitrogen, and 15 mL of diethyl ether (dehydrated) was added using a syringe substituted with nitrogen. The reaction solution was cooled to -78 ° C, and 1.6 M n-butyl lithium hexane solution (3.2 mL, 5.2 mmol) was added, then at room temperature Stir for 1 hour. The reaction solution was again cooled to -78 ° C, and diphenylphosphonium chloride (0.77 g, 3.48 mmol) was added using a nitrogen-substituted syringe. It was stirred at -78 ° C for 1 hour and at room temperature for 12 hours. After the end of the reaction, the solvent was distilled off, and the obtained solid was dissolved in dichloromethane. After removing the insoluble matter by filtration, the solvent was distilled off to obtain a white solid.

The obtained white solid was dissolved in a mixed solution of chloroform and ethanol (chloroform: ethanol = 1:1, 50 mL), and then 1 mL of H ₂ O _{2 was} added and stirred for 30 minutes. After the reaction was stopped, chloroform was added to the reaction solution, and extraction was carried out using a separatory funnel. Magnesium sulfate (anhydrous) was added to the chloroform solution obtained by extraction, and stirred at room temperature for 30 minutes. After removing magnesium sulfate by filtration, the solvent was distilled off. The obtained crude product was purified by column chromatography (yellow gel, eluting solvent: chloroform, Rf = 0.2), and sublimation purification was carried out to obtain 1.25 g (yield: 75%) of Compound 1 as a white solid. It was confirmed that the glass transition temperature (Tg) was 68 ° C, which was higher than the glass transition temperature (33 ° C) of the known compound, Compound 2.

¹ H NMR (CDCl ₃ , 500 MHz, ppm): δ 8.00 (s, 2H), 7.76-7.72 (m, 4H), 7.63-7.60 (td, 2H), 7.50-7.46 (td, 4H), 7.23-7.21 (dd, 2H), 7.15-7.13 (d, 2H), 1.39 (s, 18H).

Tg: 68 ° C

(Example 1)

In the present embodiment, an organic electroluminescence device having a light-emitting layer containing Compound 1 and a phosphorescent material was produced, and its characteristics were evaluated.

On each of the glass substrates on which the anode including indium-tin oxide (ITO) having a film thickness of 100 nm was formed, each film was laminated under vacuum at a degree of vacuum of 5.0 × 10 ^-4 Pa by vacuum deposition. First, TAPC (1,1-Bis[4-[N,N-di(p-tolyl)amino]phenyl]cyclohexane, 1,1-bis[4-[N,N-di(p-toluene) on ITO Amino]phenyl]cyclohexane) was formed to a thickness of 40 nm, and then mCP was formed to a thickness of 10 nm. Then, Compound 1 and FIr6 were co-evaporated from different vapor deposition sources to form a layer having a thickness of 20 nm to prepare a light-emitting layer. At this time, the concentration of FIr6 was set to 10% by weight. Then, DPEPO (bis(2-(diphenylphosphino)phenyl)ether oxide, bis(2-diphenylphosphinyl) diphenyl ether) was formed to a thickness of 40 nm, and lithium fluoride (LiF) was further evaporated to a thickness of 0.7 nm. Then, aluminum (Al) was vapor-deposited to a thickness of 100 nm, whereby a cathode was formed to prepare an organic electroluminescence device.

The organic electroluminescence device produced was subjected to a semiconductor parameter analyzer (manufactured by Agilent Technologies, Inc.: E5273A), an optical power meter measuring device (manufactured by NEWPORT: 1930C), and an optical spectroscope (manufactured by Ocean Optics: USB2000). Determination. The luminescence spectrum is shown in Fig. 1, the current density-voltage (J-V) characteristics are shown in Fig. 2, the luminescence intensity-voltage characteristics are shown in Fig. 3, and the current density-external quantum efficiency characteristics are shown in Fig. 4. An organic electroluminescent device having a light-emitting layer comprising Compound 1 and a phosphorescent material achieves a higher external quantum efficiency of 19.6%.

(Comparative Example 1)

The compound 1 used in Example 1 was changed to Comparative Compound 1 described below, and an organic electroluminescence device was produced and evaluated according to the same procedure as in Example 1.

The current density-voltage (J-V) characteristics of the organic electroluminescence device of Comparative Example 1 are shown in Fig. 2, the emission intensity-voltage characteristics are shown in Fig. 3, and the current density-external quantum efficiency characteristics are shown in Fig. 4.

(Example 2)

In the present embodiment, an organic photoluminescence element having a light-emitting layer containing Compound 1 and a delayed fluorescent material was produced, and its characteristics were evaluated.

On the substrate, the compound 1 and 4CzIPN were co-evaporated from different evaporation sources by vacuum evaporation at a vacuum of 5.0×10 ⁻⁴ Pa to form a film having a concentration of 6.0% by weight of 4CzIPN. Formed as an organic photoluminescent element. The luminescence spectrum of the film when irradiated with light of 337 nm by N ₂ laser was evaluated at 300 K using a C9920-02 absolute quantum yield measuring apparatus manufactured by Hamamatsu Photonics Co., Ltd., and as a result, as shown in FIG. The luminescence at 511 nm was confirmed by the emission spectrum, and it was confirmed that the luminescence quantum yield at this time was 87.3%. The time-decomposed spectrum when the element was irradiated with light of 337 nm by a N ₂ laser is shown in Fig. 6. Confirm that the delayed fluorescence component is 70%.

(Example 3)

In the present embodiment, an organic electroluminescence device having a light-emitting layer containing Compound 1 and a delayed fluorescent material was produced, and its characteristics were evaluated.

On each of the glass substrates on which the anode including indium-tin oxide (ITO) having a film thickness of 100 nm was formed, each film was laminated under vacuum at a degree of vacuum of 5.0 × 10 ^-4 Pa by vacuum deposition. First, TAPC was formed to a thickness of 40 nm on ITO, and then mCP was formed to a thickness of 10 nm. Then, the compound 1 and 4CzIPN were co-evaporated from different vapor deposition sources to form a layer having a thickness of 20 nm to prepare a light-emitting layer. At this time, the concentration of 4CzIPN was set to 6.0% by weight. Then, DPEPO was formed to a thickness of 40 nm, and lithium fluoride (LiF) was further evaporated to a thickness of 0.7 nm, and then aluminum (Al) was vapor-deposited to a thickness of 60 nm to form a cathode, thereby preparing an organic electroluminescence device.

The organic electroluminescence device produced was subjected to a semiconductor parameter analyzer (manufactured by Agilent Technologies, Inc.: E5273A), an optical power meter measuring device (manufactured by NEWPORT: 1930C), and an optical spectroscope (manufactured by Ocean Optics: USB2000). Determination. The luminescence spectrum is shown in Fig. 5, the current density-voltage (J-V) characteristics are shown in Fig. 7, the luminescence intensity-voltage characteristics are shown in Fig. 8, and the current density-external quantum efficiency characteristics are shown in the figure. 9. An organic electroluminescent device having a light-emitting layer comprising Compound 1 and a delayed fluorescent material achieves a higher external quantum efficiency of 16.8%.

(Example 4)

In the present embodiment, another organic electroluminescent element having a light-emitting layer containing Compound 1 and a delayed fluorescent material was produced, and its characteristics were evaluated.

On each of the glass substrates on which the anode including indium-tin oxide (ITO) having a film thickness of 100 nm was formed, each film was laminated under vacuum at a degree of vacuum of 5.0 × 10 ^-4 Pa by vacuum deposition. First, α-NPD was formed to a thickness of 35 nm on ITO, and then mCP was formed to a thickness of 10 nm. Then, the compound 1 and 4CzIPN were co-evaporated from different vapor deposition sources to form a layer having a thickness of 20 nm to prepare a light-emitting layer. At this time, the concentration of 4CzIPN was set to 3.0% by weight. Then, the PPT was formed to have a thickness of 40 nm, and further lithium fluoride (LiF) was vacuum-deposited to 0.8 nm, and then aluminum (Al) was vapor-deposited to a thickness of 80 nm to form a cathode, thereby preparing an organic electroluminescence device.

Further, an organic electroluminescence device was produced in the same manner as a reference example, except that an mCP known as an excellent host was used instead of the compound 1 to be changed.

For each of the organic electroluminescence elements to be manufactured, a semiconductor parameter analyzer (manufactured by Agilent Technologies, Inc.: E5273A), an optical power meter measuring device (manufactured by NEWPORT: 1930C), and an optical spectroscope (manufactured by Ocean Optics: USB2000) were used. The measurement was carried out. The luminescence spectrum is shown in Fig. 10, the current density-voltage-luminance intensity characteristic is shown in Fig. 11, and the current density-external quantum efficiency characteristic is shown in Fig. 12. An organic electroluminescent device having a light-emitting layer comprising Compound 1 and a delayed fluorescent material achieves a high external quantum efficiency of 16.0% and exhibits the same usefulness as an organic electroluminescent device using an mCP known as an excellent host. .

(Example 5)

In the present embodiment, another organic electroluminescent element having a light-emitting layer containing Compound 1 and a delayed fluorescent material was produced, and its characteristics were evaluated.

On each of the glass substrates on which the anode including indium-tin oxide (ITO) having a film thickness of 100 nm was formed, each film was laminated under vacuum at a degree of vacuum of 5.0 × 10 ^-4 Pa by vacuum deposition. First, α-NPD was formed to a thickness of 35 nm on ITO, and then mCP was formed to a thickness of 10 nm. Then, the compound 1 and CzTPN were co-evaporated from different vapor deposition sources to form a layer having a thickness of 20 nm to prepare a light-emitting layer. At this time, the concentration of CZTPN was set to 3.0% by weight. Then, the PPT was formed to have a thickness of 40 nm, and further lithium fluoride (LiF) was vacuum-deposited to 0.8 nm, and then aluminum (Al) was vapor-deposited to a thickness of 80 nm to form a cathode, thereby preparing an organic electroluminescence device.

Further, an organic electroluminescence device was produced in the same manner as a reference example, except that an mCP known as an excellent host was used instead of the compound 1 to be changed.

For each of the organic electroluminescence elements to be manufactured, a semiconductor parameter analyzer (manufactured by Agilent Technologies, Inc.: E5273A), an optical power meter measuring device (manufactured by NEWPORT: 1930C), and an optical spectroscope (manufactured by Ocean Optics: USB2000) were used. The measurement was carried out. The luminescence spectrum is shown in Fig. 13, the current density-voltage-luminance intensity characteristic is shown in Fig. 14, and the current density-external quantum efficiency characteristic is shown in Fig. 15. An organic electroluminescent device having a light-emitting layer comprising Compound 1 and a delayed fluorescent material achieves a higher external quantum efficiency of 12.8% and exhibits the same usefulness as an organic electroluminescent device using an mCP known to be an excellent host. .

[Chem. 24]

[Industrial availability]

The compound represented by the formula (1) is useful as a charge transport material. In particular, it can be effectively used as a host material for a phosphorescent material or a delayed fluorescent material. If using the general formula (1) The compound represented by the above can achieve high luminous efficiency, and thus can be applied to various industrial products. For example, it is expected to be applied to display devices such as organic electroluminescence devices, displays, backlights, electrophotography, illumination sources, exposure light sources, reading light sources, signs, billboards, and interior decoration. Therefore, the industrial availability of the present invention is high.

1‧‧‧Substrate

2‧‧‧Anode

3‧‧‧ hole injection layer

4‧‧‧ hole transport layer

5‧‧‧Lighting layer

6‧‧‧Electronic transport layer

7‧‧‧ cathode

Claims (13)

An organic electroluminescence device using a compound represented by the following formula (1), [In the formula (1), R ¹ to R ⁸ and R ¹¹ to R ²⁰ each independently represent a hydrogen atom or a substituent; R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁵ and R ⁶ , R ⁶ and R ⁷ , R ⁷ and R ⁸ , R ¹¹ and R ¹² , R ¹² and R ¹³ , R ¹³ and R ¹⁴ , R ¹⁴ and R ¹⁵ , R ¹⁶ and R ¹⁷ , R ¹⁷ and R ¹⁸ R ¹⁸ and R ¹⁹ , R ¹⁹ and R ²⁰ may be bonded to each other to form a cyclic structure]. An organic electroluminescence device according to claim 1, which has a light-emitting layer comprising a compound represented by the above formula (1) and a light-emitting material. The organic electroluminescent device of claim 2, wherein the luminescent material is a phosphorescent material. The organic electroluminescent device of claim 3, wherein the luminescent material is an Ir complex, a Cu complex or a Pt complex. The organic electroluminescent device of claim 2, wherein the luminescent material is delayed fluorescing material. The organic electroluminescent device according to any one of claims 2 to 5, wherein the luminescent material has a maximum emission wavelength of 450 to 485 nm. The organic electroluminescence device according to any one of claims 1 to 6, wherein R ¹ to R ⁸ in the above formula (1) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, substituted Or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, Substituted or unsubstituted aryloxy, substituted or unsubstituted heteroaryloxy, cyano, substituted or unsubstituted amino, substituted or unsubstituted carbazolyl, nitro, Substituted or unsubstituted fluorenyl, substituted or unsubstituted alkoxycarbonyl, substituted or unsubstituted alkylsulfonyl, hydroxy, substituted or unsubstituted alkyl guanamine, or Substituted or unsubstituted trialkylsulfonyl. The organic electroluminescence device according to any one of claims 1 to 7, wherein R ¹¹ to R ²⁰ in the above formula (1) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, substituted Or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkoxy, A substituted or unsubstituted aryloxy group, or a substituted or unsubstituted heteroaryloxy group. The organic electroluminescence device according to any one of claims 1 to 6, wherein R ¹ to R ⁸ and R ¹¹ to R ²⁰ in the above formula (1) are each independently a hydrogen atom, substituted or unsubstituted An alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryloxy group. The organic electroluminescence device according to any one of claims 1 to 9, wherein the compound represented by the above formula (1) has a structure represented by the following formula (2), [Chemical 2] [In the formula (2), R ² , R ³ , R ⁶ , R ⁷ , R ¹² to R ¹⁴ and R ¹⁷ to R ¹⁹ each independently represent a hydrogen atom or a substituent; R ² and R ³ , R ⁶ and R ⁷ , R ¹² and R ¹³ , R ¹³ and R ¹⁴ , R ¹⁷ and R ¹⁸ , and R ¹⁸ and R ¹⁹ may be bonded to each other to form a cyclic structure]. a compound represented by the following formula (1), [In the formula (1), R ¹ to R ⁸ and R ¹¹ to R ²⁰ each independently represent a hydrogen atom or a substituent; wherein at least one of R ¹ to R ⁸ and R ¹¹ to R ²⁰ is a substituent; ]. A carrier transporting material comprising a compound represented by the following formula (1), [In the formula (1), R ¹ to R ⁸ and R ¹¹ to R ²⁰ each independently represent a hydrogen atom or a substituent]. A host material comprising a compound represented by the following formula (1), [Chemical Formula 5] Formula (1) [In the formula (1), R ¹ to R ⁸ and R ¹¹ to R ²⁰ each independently represent a hydrogen atom or a substituent].