Carbazole compounds, organic layer and application thereof, organic electroluminescent device and display device

Abstract

The application discloses a carbazole compound, an organic layer and application thereof, an organic electroluminescent device and a display device. The carbazole compound has a structural formula shown in formula (1). R1 and R2 in the formula (1) are independently selected from deuterium, a halogen group, a cyano group, a C1-C10 alkyl group, a C3-C10 cycloalkyl group, a C1-C10 alkoxy group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C3-C20 heteroaryl group, a structure shown in formula (1a) or formula (1b), or any two adjacent R1 or R2 are bonded into a ring, and at least one R1 or R2 is selected from the structure shown in formula (1a) or formula (1b), or at least one R1 or R2 is selected from the structure in which at least one hydrogen in the structure shown in formula (1a) or formula (1b) is replaced by deuterium. When the carbazole compound is applied to the organic electroluminescent device, the current efficiency and service life of the device can be improved, and meanwhile, a lower working voltage is achieved.

Description

Technical Field

[0001] This application relates to the field of organic electroluminescent materials technology, specifically to a carbazole compound and an organic layer and their applications, organic electroluminescent devices, and display devices. Background Technology

[0002] Organic light-emitting diodes (OLEDs) have attracted much attention due to their thin profile, high brightness emission at low driving voltages, and ability to emit multiple colors by selecting appropriate luminescent materials. Since CWTang et al. of Kodak revealed the high brightness of organic thin-film devices, numerous researchers in the OLED industry have conducted extensive research and advancements in their applications. Organic thin-film light-emitting devices are widely used in various main displays, and their practical application has made significant progress. Despite the rapid progress in organic light-emitting device research, many problems remain to be solved, such as the need to improve the device's operating voltage, current efficiency, and lifetime. Summary of the Invention

[0003] The purpose of this application is to provide a carbazole compound and an organic layer, the application thereof, an organic electroluminescent device, and a display device, which can improve the current efficiency and lifespan of the organic electroluminescent device, while also having a lower operating voltage.

[0004] To achieve the above objectives, the first aspect of this application provides a carbazole compound with the structural formula shown in formula (1):

[0005]

[0006] In formula (1): n1 is taken from an integer from 0 to 7, n2 is taken from an integer from 0 to 7, and n1 + n2 ≥ 1; L1 and L2 are independently selected from single bonds, substituted or unsubstituted C6-C20 arylene groups, and substituted or unsubstituted C3-C20 heteroarylene groups; Ar1 ​​and Ar2 are independently selected from substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C3-C30 heteroaryl groups; R1 and R2 are independently selected from deuterium, halogen groups, cyano groups, C1-C10 alkyl groups, C3-C10 cycloalkyl groups, and C1-C10 cycloalkyl groups. The alkoxy group of 0, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C3-C20 heteroaryl group, the structure shown in formula (1a) or (1b), or any two adjacent R1 or R2 bonds forming a ring; and in the formula (1), at least one R1 or R2 is selected from the structure shown in formula (1a) or (1b), or at least one R1 or R2 is selected from the structure shown in formula (1a) or (1b) in which at least one hydrogen is substituted by deuterium, wherein the structure of formula (1a) or (1b) is as follows:

[0007]

[0008] In equations (1a) and (1b): * represents the bonding site; R 20 and R 30 Independently selected from halogen groups, cyano groups, C1-C10 alkyl groups, C3-C10 cycloalkyl groups, C1-C10 alkoxy groups, C6-C20 aryl groups, and C3-C20 heteroaryl groups; n20 and n30 are independently taken from integers from 0 to 3; R 21 ~R 26 R 31 ~R 38 A group independently selected from hydrogen, deuterium, methyl or methyl in which at least one hydrogen atom is substituted by deuterium.

[0009] In some embodiments of this application, formula (1a) is selected from the following structures:

[0010]

[0011] Equation (1b) is selected from the following structures:

[0012]

[0013] In some embodiments of this application, R1 and R2 are independently selected from deuterium, the structure shown in formula (1a) or formula (1b), or any two adjacent R1 or R2 bonded to form a benzene ring, or substituted or unsubstituted of the following preferred groups: phenyl, naphthyl, fluorenyl, dibenzofuranyl, dibenzothiopheneyl, wherein the substituent of the preferred groups is selected from deuterium, halogen groups, cyano, C1-C5 alkyl, C1-C6 cycloalkyl, adamantyl, or phenyl.

[0014] In some embodiments of this application, L1 and L2 are independently selected from single-bonded or substituted or unsubstituted groups of the following: phenylene, naphthylene, fluorene, dibenzofuranyl, dibenzothiophene; and Ar1 and Ar2 are independently selected from substituted or unsubstituted groups of the following: phenyl, naphthyl, diphenyl, fluorene, dibenzofuranyl, dibenzothiophene.

[0015] In some embodiments of this application, the substituents of L1, L2, Ar1 and Ar2 may be the same or different from each other, and each is independently selected from deuterium, halogen groups, cyano, C1-C10 alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C6-C20 aryl, and C3-C20 heteroaryl.

[0016] In some embodiments of this application, the structural formula of the carbazole compound is selected from the following:

[0017]

[0018] In some embodiments of this application, the carbazole compound is represented by any of the structural formulas 1 to 148, in which: n2 is selected from integers from 0 to 7; R2 is selected from deuterium, the structure shown in formula (1a) or formula (1b), or any two adjacent R2s bonded together to form a benzene ring, or substituted or unsubstituted of the following preferred groups: phenyl, naphthyl, fluorenyl, dibenzofuranyl, dibenzothiophene, wherein the substituent of the preferred group is selected from deuterium, halogen groups, cyano, C1-C5 alkyl, C1-C6 cycloalkyl, adamantyl, or phenyl; L2 is selected from single bonds or substituted or unsubstituted of the following groups: phenylene, naphthylene, fluorenylene, dibenzofuranyl, dibenzothiophene; Ar2 is selected from substituted or unsubstituted of the following groups: phenyl, naphthyl, diphenyl, fluorenyl, dibenzofuranyl, dibenzothiophene.

[0019] In some embodiments of this application, the carbazole compounds are selected from: compound 1-1, compound 2-1 to compound 120-1, compound 2-2, compound 61-2 to compound 61-4, compound 91-2, compound 91-3, compound 97-2, compound 121-1, compound 122-1, compound 124-1 to compound 147-1, compound 129-2, compound 130-2, compound 131-2, compound 131-3, compound 132-2, and compound 132-3.

[0020] A second aspect of this application provides an organic layer comprising any of the carbazole compounds described above and / or the aforementioned organic layer in an organic electroluminescent device.

[0021] A third aspect of this application also provides an organic electroluminescent device, comprising a first electrode, a second electrode, and the aforementioned organic layer, wherein the organic layer comprises at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, and an electron transport layer.

[0022] A fourth aspect of this application also provides a display device including the aforementioned organic electroluminescent device.

[0023] The carbazole compounds of this application introduce benzocycloalkyl segments into the carbazole molecule. On the one hand, this increases the conjugation degree of the carbazole molecule, making it more conducive to carrier transport. On the other hand, the presence of non-planar benzocycloalkyl segments reduces the intermolecular interaction forces of the carbazole molecule, making the molecule less prone to crystallization and facilitating the formation of dense, uniform, and stable amorphous thin films. At the same time, it can increase the glass transition temperature of the carbazole molecule, thereby improving the heat resistance of the device. Therefore, when the carbazole compounds of this application are used in electroluminescent devices, they can improve the lifetime and current efficiency of organic electroluminescent devices and reduce the operating voltage. Attached Figure Description

[0024] The following accompanying drawings describe in detail the exemplary embodiments disclosed in this application. The same reference numerals denote similar structures in several views of the drawings. Those skilled in the art will understand that these embodiments are non-limiting and exemplary, and the drawings are for illustrative purposes only and are not intended to limit the scope of this application. Other embodiments may similarly fulfill the inventive intent of this application. It should be understood that the drawings are not drawn to scale. Wherein:

[0025] Figure 1 This is a schematic diagram of the structure of the organic electroluminescent device prepared in Example 31 of this application. Detailed Implementation

[0026] The following description provides specific application scenarios and requirements for this application, intended to enable those skilled in the art to make and use the content of this application. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this application. Therefore, this application is not limited to the embodiments shown, but rather to the widest scope consistent with the claims.

[0027] Carbazole molecules have good hole transport capabilities and high triplet energy levels, and can often be used as electron blocking layer materials or light-emitting layer materials. However, as people have increasingly higher requirements for the performance of electronic components, it is still necessary to continue to develop new materials to further improve the performance of electronic components.

[0028] Based on this, this application introduces benzocycloalkyl fragments into carbazole molecules, thereby effectively extending the conjugation length of the molecules and enhancing the carrier transport capability, especially the hole transport capability. This, in turn, helps to improve the current efficiency of organic electroluminescent devices and maintain a low operating voltage. Simultaneously, the introduction of benzocycloalkyl fragments reduces intermolecular forces, facilitating the acquisition of dense, uniform, and stable amorphous thin films. When used as electron blocking layer materials, this reduces leakage current in the device. Furthermore, the compounds in this application possess high glass transition temperatures, improving the heat resistance of the device and significantly extending its lifetime. In addition, the carbazole compounds provided in this application exhibit good solubility, and their synthesis and purification processes are simple.

[0029] Examples of substituents appearing in this application are described below, but the substituents are not limited thereto:

[0030] Substitution or unsubstituted: refers to substitution by one or more substituents selected from the following: deuterium, halogen group, cyano, nitro, hydroxyl, carbonyl, ester group, imide group, amino, phosphine oxide group, alkoxy, aryloxy, alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, silyl, boron, straight-chain or branched or cyclic alkyl, alkenyl, aryl, aralkyl, arylenyl, alkylaryl, alkylamine, aralkylamine, heteroarylamine, arylamine, arylphosphine, heterocyclic, or unsubstituted; or substitution by a substituent that connects two or more substituents from the examples above, or unsubstituted. For example, "a substituent that connects two or more substituents" may include biphenyl, i.e., biphenyl may be aryl, or a substituent that connects two phenyl groups. Among the substituents mentioned above, the alkoxy group is preferably a C1 to C10 alkoxy group. The straight-chain, branched, or cyclic alkyl group is preferably a C1-C30 alkyl group, such as a C1-C10 alkyl group or a C3-C10 cycloalkyl group. The C1-C10 alkyl group is, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, methyl-substituted isobutyl, methyl-substituted tert-butyl, etc.

[0031] Aryl group: Not particularly limited, but preferably C6 to C20 aryl groups. The aryl group can be monocyclic or polycyclic. In some embodiments, monocyclic aryl groups include, but are not limited to, phenyl, biphenyl, terphenyl, tetraphenyl, and pentaphenyl. Polycyclic aryl groups include, but are not limited to, naphthyl, anthracene, phenanthryl, pyrene, perylene, and fluorene. The fluorene group can be substituted, such as 9,9'-dimethylfluorenel or 9,9'-dibenzofluorenel. Furthermore, two of the substituents can combine with each other to form a spirocyclic structure, such as 9,9'-spirodifluorenel.

[0032] The above description of aryl can be applied to arylene, the difference being that arylene is divalent.

[0033] The above description of aryl groups can be applied to aryl groups in the following categories: aryloxy, arylthio, arylsulfonyl, arylphosphinyl, aralkyl, arylalkylamine, arylenyl, alkylaryl, arylamine, and arylheteroarylamine.

[0034] Heterocyclic groups: Containing one or more of B, N, O, P, S, Si, and Se as heteroatoms. Heterocyclic groups include, but are not limited to, pyridinyl, pyrrolyl, pyrimidinyl, pyridazinyl, furanyl, thiopheneyl, imidazolyl, pyrazolyl, azole, isozolyl, thiazolyl, isothiazolyl, triazolyl, diazolyl, thiadiazolyl, dithiazolyl, tetrazolyl, pyranyl, thiaranyl, pyrazinyl, azinyl, thiazolyl, dioxazinyl, dioxazinyl, triazinyl, tetraazinyl, quinolinyl, isoquinolinyl, quinolinyl, quinazolinyl, quinoxalinyl, naphridinyl, acridineyl, xanthonyl, phenanthridineyl, diazanaphthyl, triazaindole, indoleyl, dihydroindoleyl, nitro-indoleyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazino Pyrazinyl, benzothiazolyl, benzoxazolyl, benzimidazolyl, benzothiopheneyl, benzofuranyl, dibenzothiopheneyl, dibenzofuranyl, carbazoleyl, benzocarbazoleyl, dibenzocarbazoleyl, indolocarbazoleyl, indocarbazoleyl, phenazinyl, imidazopyridyl, phenazinyl, phenanthrinyl, phenanthiazinyl, imidazopyridyl, imidazophenanthrinyl, benzimidazoquinazolinyl, benzimidazophenanthrinyl, spiro[fluorene-9,9'-oxazanthracene], phenylbinaphthyl, dinaphthofuranyl, naphthobenzofuranyl, dinaphthothiopheneyl, naphthobenzothiopheneyl, triphenylphosphine oxide, triphenylborane, etc. Preferably, heterocyclic groups of C3 to C20 are used.

[0035] The above description of heterocyclic groups can be applied to heteroaryl groups, the difference being that heteroaryl groups are aromatic.

[0036] The above description of heterocyclic groups can be applied to heteroaryl, heteroarylamine, and heteroaryl-heteroarylamine groups.

[0037] The above description of heterocyclic groups can be applied to heteroaryl groups, the difference being that heteroaryl groups are divalent.

[0038] Alkyl groups can be straight-chain, branched, or cyclic, and there is no particular limitation on the number of carbon atoms. In some embodiments, alkyl groups include, but are not limited to, methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 4-methylhexyl, 5-methylhexyl, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, etc.

[0039] The above description of alkyl groups can be applied to alkyl thio, alkyl sulfonyl, aralkyl, aralkylamine, alkylaryl, and alkylamine groups.

[0040] One aspect of this application provides a carbazole compound having the structural formula shown in formula (1):

[0041]

[0042] In formula (1): n1 is taken from an integer from 0 to 7, n2 is taken from an integer from 0 to 7, and n1+n2≥1; L1 and L2 are independently selected from single bonds, substituted or unsubstituted C6-C20 aryl groups, substituted or unsubstituted C3-C20 heteroaryl groups; Ar1 ​​and Ar2 are independently selected from substituted or unsubstituted C6-C30 aryl groups, substituted or unsubstituted C3-C30 heteroaryl groups; R1 and R2 are independently selected from deuterium, halogen groups, cyano groups, C1-C10 alkyl groups, C3-C10 cycloalkyl groups, C1-C10 alkoxy groups, substituted or unsubstituted C6-C20 aryl groups, substituted or unsubstituted C3-C20 heteroaryl groups, the structure shown in formula (1a) or formula (1b), or any two adjacent R1 or R2 bonds forming a ring.

[0043] Meanwhile, in formula (1), at least one R1 or R2 is selected from the structure shown in formula (1a) or formula (1b), or at least one R1 or R2 is selected from the structure shown in formula (1a) or formula (1b) in which at least one hydrogen is replaced by deuterium, wherein the structure of formula (1a) or formula (1b) is as follows:

[0044]

[0045] In equations (1a) and (1b): * represents the bonding site; R 20 and R 30Independently selected from halogen groups, cyano groups, C1-C10 alkyl groups, C3-C10 cycloalkyl groups, C1-C10 alkoxy groups, C6-C20 aryl groups, and C3-C20 heteroaryl groups; n20 and n30 are independently taken from integers from 0 to 3; R 21 ~R 26 R 31 ~R 38 A group independently selected from hydrogen, deuterium, methyl or methyl in which at least one hydrogen atom is substituted by deuterium.

[0046] It should be noted that in equation (1), the substitution of R1 and R2 is not limited to a single benzene ring of the carbazole group, nor is the specific substitution position restricted. That is, R1 and R2 can each substitute a single benzene ring of the carbazole group, or simultaneously substitute both benzene rings of the carbazole group. Furthermore, the substitution of R1 and R2 can occur at any substituted position on the benzene ring; it can occur at one substituted position on the benzene ring, or simultaneously at at least two substituted positions on the benzene ring. In short, R1 and R2 can each arbitrarily substitute on the two benzene rings of the carbazole group. Similarly, in equation (1a), R... 20 It can be substituted in any way on the benzene ring. In formula (1b), R 30 It can be substituted in any way on the benzene ring.

[0047] In some preferred embodiments, formula (1a) is selected from the following structures:

[0048]

[0049] In some more preferred embodiments, formula (1a) is selected from the following structures:

[0050]

[0051] In some preferred embodiments, formula (1b) is selected from the following structures:

[0052]

[0053] In some more preferred embodiments, formula (1b) is selected from the following structures:

[0054]

[0055] In some preferred embodiments, R1 and R2 are independently selected from deuterium, the structure shown in formula (1a) or formula (1b), or any two adjacent R1 or R2 bonded to form a benzene ring, or substituted or unsubstituted of the following preferred groups: phenyl, naphthyl, fluorenyl, dibenzofuranyl, dibenzothiopheneyl, wherein the substituent of the preferred groups is selected from deuterium, halogen groups, cyano, C1-C5 alkyl, C1-C6 cycloalkyl, adamantyl, or phenyl.

[0056] In some preferred embodiments, L1 and L2 are independently selected from single-bonded or substituted or unsubstituted groups of the following: phenylene, naphthylene, fluorene, dibenzofuranyl, dibenzothiophene; and Ar1 and Ar2 are independently selected from substituted or unsubstituted groups of the following: phenyl, naphthyl, diphenylphenyl, diphenylbenzene, fluorene, dibenzofuranyl, dibenzothiophene, tert-butyl. In some preferred embodiments, the substituents of L1, L2, Ar1, and Ar2 may be the same or different from each other, and are each independently selected from deuterium, halogen groups, cyano, C1-C10 alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C6-C20 aryl, and C3-C20 heteroaryl.

[0057] In some preferred embodiments, the substitution positions of R1 are as follows:

[0058]

[0059] In the above four structural formulas, R1 is substituted by monosubstitution on one of the benzene rings of the carbazo group, and can be in a relative positional relationship of opposite, ortho, or meta with the N atom, while R2 can be substituted arbitrarily on the two benzene rings of the carbazo group.

[0060] In some more preferred embodiments, the carbazole compound is represented by any of the following structural formulas: Formula 1 to Formula 148.

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068] In Formulas 1 to 148: n2 is selected from integers from 0 to 7; R2 is selected from deuterium, the structure shown in Formula (1a) or Formula (1b), or any two adjacent R2s bonded to form a benzene ring, or substituted or unsubstituted of the following preferred groups: phenyl, naphthyl, fluorenyl, dibenzofuranyl, dibenzothiophene, wherein the substituent of the preferred group is selected from deuterium, halogen group, cyano, C1-C5 alkyl, C1-C6 cycloalkyl, adamantyl or phenyl; L2 is selected from single bond or substituted or unsubstituted of the following groups: phenylene, naphthylene, fluorenylene, dibenzofuranyl, dibenzothiophene; Ar2 is selected from substituted or unsubstituted of the following groups: phenyl, naphthyl, diphenyl, fluorenyl, dibenzofuranyl, dibenzothiophene.

[0069] In some specific embodiments, the carbazole compound may be one of the following compounds:

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076] This application also provides an organic layer comprising any of the aforementioned carbazole compounds. Both the aforementioned carbazole compounds and the organic layer can be used in organic electroluminescent devices.

[0077] This application also provides an organic electroluminescent device, comprising a first electrode, a second electrode, and the aforementioned organic layer. As an example, the first electrode is an anode, and the second electrode is a cathode, which may be one or more layers. The organic layer is located between the first electrode and the second electrode. The organic layer may be a single-layer structure or a multilayer tandem structure with two or more organic layers laminated together. The organic layer includes at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, and an electron transport layer. In some preferred embodiments, the carbazole compound of this application is used as an electron blocking layer material and / or a host material for the light-emitting layer. In some specific embodiments of this application, the organic electroluminescent device is a green organic electroluminescent device.

[0078] In some specific embodiments, the structure of the organic electroluminescent device may be selected from one of the following:

[0079] (1) An organic electroluminescent device includes an anode, a hole injection layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, and a cathode stacked in sequence, that is, anode / hole injection layer / first hole transport layer / light-emitting layer / first electron transport layer / cathode. The device structure will be expressed in this simplified way below.

[0080] (2) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / cathode.

[0081] (3) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / cathode.

[0082] (4) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / electron injection layer / cathode.

[0083] (5) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / multilayer cathode.

[0084] (6) Anode / hole injection layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / cathode.

[0085] (7) Anode / hole injection layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / second electron transport layer / cathode.

[0086] (8) Anode / hole injection layer / second hole transport layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / cathode.

[0087] (9) Anode / hole injection layer / second hole transport layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / second electron transport layer / cathode.

[0088] (10) Anode / hole injection layer / hole transport layer / electron blocking layer / light emission layer / electron transport layer / electron injection layer / cathode.

[0089] (11) Anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / hole blocking layer / electron transport layer / cathode.

[0090] (12) Anode / hole injection layer / hole transport layer / electron blocking layer / light emitting layer / electron transport layer / cathode.

[0091] (13) Anode / hole injection layer / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / cathode.

[0092] The organic electroluminescent device can emit light from either the anode side or the cathode side. In some specific embodiments, it emits light from the cathode side, which requires adding a capping layer on the cathode side, as shown in the following structure:

[0093] 1) Anode / hole injection layer / first hole transport layer / light emission layer / first electron transport layer / cathode / capping layer.

[0094] 2) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / cathode / capping layer.

[0095] 3) Anode / hole injection layer / second hole transport layer / first hole transport layer / light emission layer / first electron transport layer / second electron transport layer / cathode / capping layer.

[0096] 4) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / electron injection layer / cathode / capping layer.

[0097] 5) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / multilayer cathode / capping layer.

[0098] 6) Anode / hole injection layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / cathode / capping layer.

[0099] 7) Anode / hole injection layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / second electron transport layer / cathode / capping layer.

[0100] 8) Anode / Hole Injection Layer / Second Hole Transport Layer / First Hole Transport Layer / First Light Emitting Layer / Carrier Generation Layer / First Hole Transport Layer / Second Light Emitting Layer / First Electron Transport Layer / Cathode / Covering Layer.

[0101] 9) Anode / Hole Injection Layer / Second Hole Transport Layer / First Hole Transport Layer / First Light Emitting Layer / Carrier Generation Layer / First Hole Transport Layer / Second Light Emitting Layer / First Electron Transport Layer / Second Electron Transport Layer / Cathode / Covering Layer.

[0102] 10) Anode / hole injection layer / hole transport layer / electron blocking layer / light emission layer / electron transport layer / electron injection layer / cathode / capping layer.

[0103] 11) Anode / Hole injection layer / First hole transport layer / Second hole transport layer / Light emission layer / Hole blocking layer / Electron transport layer / Cathode / Covering layer.

[0104] 12) Anode / hole injection layer / hole transport layer / electron blocking layer / light emission layer / electron transport layer / cathode / capping layer.

[0105] 13) Anode / hole injection layer / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / cathode / capping layer.

[0106] The following describes some specific functional layers in the organic electroluminescent device.

[0107] Substrate:

[0108] The substrate is generally located below the anode. The substrate can be made of plastic or glass, and can be rigid or flexible. The substrate has a driving unit that can drive the corresponding pixel to emit light.

[0109] anode:

[0110] Organic EL (Organic Electro-Luminescence) devices typically require the anode to have good conductivity, a smooth surface, and be resistant to cracking. They also have certain requirements for work function, mainly to match the hole injection layer and achieve the hole injection effect.

[0111] When using a top-emitting method (cathode-side light emission), the anode is a metal compound with a work function of 4.2 eV or higher, such as indium tin oxide, tin oxide, indium zinc oxide, gold, silver, platinum, copper, carbon nanotubes, carbon nanowires, graphene, etc. The thickness is 10 nm to 200 nm, preferably 10 nm to 50 nm. A reflective electrode is placed below the anode (near the substrate end). The reflective electrode is generally made of metal or metal alloy, such as silver, copper, aluminum, gold, or alloys of these metals with other metals. The reflective electrode has high reflectivity, requiring a reflectivity of over 90%, and its thickness is typically between 100 nm and 500 nm, preferably in the range of 80 nm to 150 nm.

[0112] When bottom-emitting (light emission from the cathode side) is used, the anode is a metal compound with a work function of 4.2 eV or higher, such as indium tin oxide alloy, tin oxide, indium zinc oxide, gold, silver, platinum, copper, carbon nanotubes, carbon nanowires, graphene, etc. The thickness is 10 nm to 1 μm, preferably 50 nm to 200 nm.

[0113] The anode can be made by forming a thin film from the electrode material using methods such as vapor deposition, sputtering, or coating.

[0114] Hole injection layer:

[0115] The thickness of the hole injection layer is typically 3 nm to 20 nm. The hole injection layer uses a mixture of P-type and hole transport materials. The purpose of using P-type materials is to accept holes from the anode and transfer them to the hole transport material. The weight percentage of P-type materials in the hole injection layer is typically 0.5% to 10%. When the weight percentage is 0.5% to 3%, the absolute value of the difference between the lowest unoccupied molecular orbital (LUMO) energy level of the P-type material and the highest occupied molecular orbital (HOMO) energy level of the HTL material must not exceed 0.3 eV. When the weight percentage is 3% to 5%, the absolute value of the difference between the lowest unoccupied molecular orbital (LUMO) energy level of the P-type material and the highest occupied molecular orbital (HOMO) energy level of the HTL material must not exceed 0.5 eV. When the weight percentage is 5% to 10%, the absolute value of the difference between the lowest unoccupied molecular orbital (LUMO) energy level of the P-type material and the highest occupied molecular orbital (HOMO) energy level of the HTL material must not exceed 1 eV.

[0116] P-type materials can be metal oxides, such as molybdenum oxide, vanadium oxide, and tungsten oxide; they can also be organic compounds, such as 4,4',4”-((1E,1'E,1”E)-cyclopropane-1,2,3-trimethylenetris(cyanoformyl))tris(2,3,5,6-tetrafluorobenzyl) (PD1, CAS No.: 1224447-88-4), tetracyanoquinone dimethyl (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinone dimethyl (F4-TCNQ), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN), and are not limited to these. The hole transport material paired with the P-type material can be selected from the material of the second hole transport layer, and can be the same as or different from the material of the second hole transport layer.

[0117] Second hole transport layer:

[0118] The thickness of the second hole transport layer is typically 40 nm to 150 nm, and it often uses aryl amine compounds, such as monoaryl amines or polyaryl amines. Hole transport materials are required to have high hole mobility, reduce driving voltage, and have a glass transition temperature exceeding 100°C to avoid crystallization at high temperatures.

[0119] First hole transport layer:

[0120] The thickness of the first hole transport layer is typically 3nm to 220nm. When there is no second hole transport layer, the thickness of the first hole transport layer is typically 40nm to 150nm; when there is a second hole transport layer, the thickness of the first hole transport layer is typically 3nm to 120nm. Generally, red, green, blue, and yellow light require thickness adjustments based on the "microcavity effect," and the thickness selection varies. Taking a top-emitting light-emitting device as an example, the formula for the microcavity is as follows:

[0121]

[0122] Where n i and d i θ1 and θ2 represent the refractive index coefficient and thickness of the i-th layer, respectively, m is an integer and is the modulus of the microcavity, commonly 1 or 2; θ1 and θ2 represent the phase shifts generated by light at the anode and cathode interfaces, respectively.

[0123] Red, green, blue, and other colored light have different wavelengths, so each color has its optimal thickness. Taking a modulus of 2 as an example, for red light, without a second hole transport layer, the thickness of the first hole transport layer is generally 160nm–220nm; with a second hole transport layer, the thickness of the first hole transport layer is generally 8nm–120nm. For green light, without a second hole transport layer, the thickness of the first hole transport layer is generally 100nm–180nm; with a second hole transport layer, the thickness of the first hole transport layer is generally 30nm–70nm. For blue light, without a second hole transport layer, the thickness of the first hole transport layer is generally 80nm–130nm; with a second hole transport layer, the thickness of the first hole transport layer is generally 3nm–30nm. Different optimal "microcavity adjustment thicknesses" will be selected for other colors.

[0124] Electron blocking layer:

[0125] The electron blocking layer can simultaneously possess both hole transport and electron blocking functions. Furthermore, the higher triplet excitation energy level of the electron blocking layer can confine excitons generated in the emissive layer within it, thereby improving the device's luminous efficiency.

[0126] Emissive layer:

[0127] The material of the light-emitting layer generally includes a host material and a guest dopant material, wherein the content of the host material is greater than that of the guest dopant material. Optionally, the mass percentage of the guest dopant material in the light-emitting layer is 1% to 20%.

[0128] Guest dopants used as luminescent materials can include phosphorescent or fluorescent materials or thermally activated delayed fluorescence materials. Red, green, and blue light can be selected from these three types of guest dopants. For example, the guest dopant material for the luminescent layer corresponding to a red luminescent unit and the luminescent layer corresponding to a green luminescent unit is a phosphorescent material, while the guest dopant material for the luminescent layer corresponding to a blue luminescent unit is a fluorescent material.

[0129] For example, the guest doping material of the light-emitting layer corresponding to the light-emitting unit with a red emission color and the light-emitting layer corresponding to the light-emitting unit with a green emission color is a phosphorescent material, and the guest doping material of the light-emitting layer corresponding to the light-emitting unit with a blue emission color is a phosphorescent material.

[0130] For example, the guest doping material of the light-emitting layer corresponding to the light-emitting unit with a red emission color and the light-emitting layer corresponding to the light-emitting unit with a green emission color is a thermally activated delayed fluorescence material, and the guest doping material of the light-emitting layer corresponding to the light-emitting unit with a blue emission color is a fluorescent material.

[0131] For example, the guest doping material of the light-emitting layer corresponding to the light-emitting unit with a red emission color and the light-emitting layer corresponding to the light-emitting unit with a green emission color is a thermally activated delayed fluorescence material, and the guest doping material of the light-emitting layer corresponding to the light-emitting unit with a blue emission color is a phosphorescent material.

[0132] To reduce the power consumption of organic light-emitting display panels in organic electroluminescent devices, guest doping materials with superior luminescent properties can be selected. Taking a top-emitting device as an example, optionally, the light-emitting unit with a red emission color has a luminous intensity of 1000 cd / m². 2 A green light-emitting unit with a current efficiency greater than 30 cd / A and a luminous intensity of 6000 cd / m² is used. 2 A light-emitting unit with a current efficiency greater than 100 cd / A and a fluorescent blue emission color has a luminous intensity of 1000 cd / m². 2 With a current efficiency greater than 5 cd / A as the standard, and by selecting suitable guest doping materials, a phosphorescent blue emitting unit is achieved with a luminous intensity of 1000 cd / m². 2 The standard is a current efficiency greater than 10 cd / A. Higher current efficiency can reduce power consumption.

[0133] As the main light-emitting material, one or two main light-emitting materials can be selected.

[0134] Cavity blocking layer:

[0135] To enhance the balance between hole and electron concentrations, a hole blocking layer is inserted to balance carrier concentration and prevent exciton quenching. Typically, the hole blocking layer is located between the emitting layer and the electron transport layer, and the hole blocking layer material must meet conditions such as high stability, good film-forming properties, and a sufficiently high highest molecular occupied orbital.

[0136] First electron transport layer:

[0137] The thickness of the first electron transport layer can typically be 3nm–40nm, 3nm–10nm, 10nm–20nm, 20nm–30nm, 30nm–40nm, or 20nm–40nm. When there is no second electron transport layer, the thickness of the first electron transport layer is typically 20nm–50nm; when there is a second electron transport layer, the thickness of the first electron transport layer is typically 40nm–20nm. The first electron transport layer is in direct contact with the emitting layer, and therefore, similar to the first hole transport layer, it also undergoes electronic changes during electron transport, leading to increased molecular vibration and deformation. Furthermore, the interaction between the excitons of the emitting layer and the polarons of the electron transport material can easily generate reactive free radicals, which can damage the electron transport material. The electron transport material can be a single compound or a mixture of other metals or metal compounds. Electron transport materials can include mixtures of organic electron transport materials and metal compounds, or mixtures of organic electron transport materials and metals.

[0138] When organic electron transport materials are mixed with metal compound materials, such as alkali metal compounds, alkaline earth metal compounds, and rare earth metal compounds, more specifically, they can be mixed with lithium metal compounds, calcium metal compounds, Mg metal compounds, samarium metal compounds, ytterbium metal compounds, etc., and even more specifically, they can be mixed with lithium 8-hydroxyquinoline, lithium fluoride, magnesium fluoride, ytterbium fluoride, calcium fluoride, etc. When used in combination with metal compounds, the mass percentage of the organic electron transport material can be 20%–80%, 20%–40%, 40%–60%, or 60%–80%, etc.

[0139] When organic electron transport materials are used in combination with metals, such as alkali metals, alkaline earth metals, and rare earth metals, or more specifically, with lithium metal, magnesium metal, calcium metal, ytterbium metal, and samarium metal, the mass ratio of the organic electron transport material can be 80%–99%, 80%–89%, 89%–99%, 80%–85%, 85%–90%, 90%–95%, or 95%–99%, etc.

[0140] Second electron transport layer:

[0141] The thickness of the second electron transport layer is generally 10 nm to 40 nm. The material of the second electron transport layer may include a mixture of organic electron transport materials and metal compounds, or a mixture of organic electron transport materials and metals.

[0142] When organic electron transport materials are mixed with metal compound materials, such as alkali metal compounds, alkaline earth metal compounds, and rare earth metal compounds, more specifically, they can be mixed with lithium metal compounds, calcium metal compounds, Mg metal compounds, samarium metal compounds, ytterbium metal compounds, etc., and even more specifically, they can be mixed with lithium 8-hydroxyquinoline, lithium fluoride, magnesium fluoride, ytterbium fluoride, calcium fluoride, etc. When used in combination with metal compounds, the mass percentage of the organic electron transport material can be 20%–80%, 20%–40%, 40%–60%, or 60%–80%, etc.

[0143] When organic electron transport materials are used in combination with metals, such as alkali metals, alkaline earth metals, and rare earth metals, or more specifically, with lithium metal, magnesium metal, calcium metal, ytterbium metal, and samarium metal, the mass ratio of the organic electron transport material can be 80%–99%, 80%–89%, 89%–99%, 80%–85%, 85%–90%, 90%–95%, or 95%–99%, etc.

[0144] Charge generation layer:

[0145] When a single-layer light-emitting device is used, holes and electrons are injected from the anode and cathode respectively, eliminating the need for a charge generation layer. When using double or multiple light-emitting layers, a charge generation layer is required between the light-emitting layers to achieve charge generation, injection, and transport. This charge generation layer is located between the two light-emitting layers and is typically composed of two P / N type materials. The P-type material is selected from the hole injection materials mentioned earlier, while the N-type material is a mixture of organic electron transport materials and metals. The organic electron transport layer material is selected from the second electron transport layer mentioned earlier, and the metal is selected from alkali metals, alkaline earth metals, and rare earth metals. More specifically, examples include lithium, magnesium, calcium, ytterbium, and samarium. When organic electron transport materials are mixed with metals, the mass percentage of the organic electron transport material can be 80%–99%, 80%–89%, 89%–99%, 80%–85%, 85%–90%, 90%–95%, or 95%–99%, etc.

[0146] cathode:

[0147] The cathode requires materials with good electrical conductivity and a smooth surface. To improve electron injection capability, materials with a low work function are typically chosen. Cathode materials can be single-layer, double-layer, or multi-layer cathodes, generally made of metals or metal alloys. For single-layer cathodes, silver, copper, aluminum, gold, or alloys of these metals with other metals, such as rare earth metals, alkali metals, and alkaline earth metals, can be used. Examples include magnesium-indium alloys, magnesium-aluminum alloys, aluminum-potassium alloys, aluminum-scandium-potassium alloys, magnesium-silver alloys, silver-ytterbium alloys, and silver-samarium alloys. If a double-layer metal cathode is used, the cathode layer closer to the light-emitting layer can be made of alkali metals, alkaline earth metals, or rare earth metals, such as lithium, calcium, magnesium, and ytterbium, to increase electron injection capability. The cathode layer farther from the light-emitting side is mainly used to improve conductivity, and generally uses silver, copper, aluminum, gold, or alloys of these metals with other metals, such as alloys with rare earth metals, alkali metals, or alkaline earth metals. Examples include magnesium-indium alloys, magnesium-aluminum alloys, aluminum-potassium alloys, aluminum-scandium-potassium alloys, magnesium-silver alloys, silver-ytterbium alloys, and silver-samarium alloys. The cathode can also be formed into a thin film using methods such as vapor deposition or sputtering.

[0148] When light comes out from the anode side, the cathode must be opaque, and a cathode with a thickness greater than 100 nm can be deposited. When light comes out from the cathode side, the cathode must be transparent, with a transmittance greater than 40% and a thickness of 10 nm to 20 nm.

[0149] Overlay:

[0150] The refractive index n and absorption coefficient of a single-layer capping layer must meet the following conditions:

[0151] The refractive index n(450~650nm) is >1.8 between wavelengths of 450~650nm, and the extinction coefficient between wavelengths of 450~650nm is less than 0.1; the extinction coefficient at 380nm is greater than 0.2; the difference between the refractive index at 450nm and the refractive index at 530nm is n(450nm)-n(530nm)<0.5, more preferably n(450nm)-n(530nm)<0.3; the difference between the refractive index at 510nm and the refractive index at 620nm is n(510nm)-n(620nm)<0.4, more preferably the difference between the refractive index at 510nm and the refractive index at 620nm is n(510nm)-n(620nm)<0.2.

[0152] Materials that can meet the requirements of the covering layer for refractive index n can further achieve high luminous efficiency of the device, while the light output efficiency and viewing angle of red, green and blue light are more balanced.

[0153] In some specific embodiments, the thickness of the cover layer is 50nm to 90nm, for example, 50nm, 55nm, 57nm, 59nm, 62nm, 64nm, 67nm, 68nm, 70nm, 75nm, 77nm, 79nm, 80nm, 82nm, 85nm, 88nm, 90nm, etc.

[0154] The cover layer is formed after the semi-transparent cathode of the OLED display panel is away from the substrate, and the stack formed by the cover layer and the semi-transparent cathode can achieve a light transmittance of ≥65% for light between 450nm and 650nm, such as 68%, 69%, 73%, 77%, 79%, 83%, 88%, 93%, etc.

[0155] When using two capping layers, the refractive index n and absorption coefficient need to satisfy the following conditions:

[0156] The capping layer (first capping layer) near the cathode side has a refractive index n450-650nm<1.8 between wavelengths of 450-650nm, and an extinction coefficient between wavelengths of 450-650nm is less than 0.1; the extinction coefficient at any wavelength between 250nm and 350nm is greater than 0.3, preferably greater than 0.6.

[0157] The capping layer (second capping layer) away from the cathode has a refractive index n450-650nm>1.8 between wavelengths of 450-650nm, and an extinction coefficient between wavelengths of 450-650nm below 0.1; the extinction coefficient at 380nm is greater than 0.1, and more preferably greater than 0.2.

[0158] The difference between the refractive index of 450nm and the refractive index of 530nm, n(450nm)-n(530nm)<0.5, is more preferably n(450nm)-n(530nm)<0.3.

[0159] The difference between the refractive index of 510nm and 620nm, n(510nm)-n(620nm)<0.4, is even better than the difference between the refractive index of 450nm and 530nm, n(450nm)-n(530nm)<0.2.

[0160] The total thickness of the double-layer capping layer is 50nm to 90nm, for example: 50nm, 55nm, 57nm, 59nm, 62nm, 64nm, 67nm, 68nm, 70nm, 75nm, 77nm, 79nm, 80nm, 82nm, 85nm, 88nm, 90nm, etc.

[0161] The thickness of the capping layer (first capping layer) near the cathode side is 5nm to 40nm, for example: 5nm, 7nm, 10nm, 12nm, 15nm, 18nm, 20nm, 22nm, 25nm, 27nm, 30nm, 32nm, 34nm, 36nm, 38nm, 40nm, etc.

[0162] The thickness of the capping layer (second capping layer) away from the cathode side is 35nm to 85nm, for example: 35nm, 40nm, 43nm, 45nm, 48nm, 50nm, 55nm, 57nm, 59nm, 62nm, 64nm, 67nm, 68nm, 70nm, 75nm, 77nm, 79nm, 80nm, 82nm, 85nm, etc.

[0163] This application also provides a display device, including the aforementioned organic electroluminescent device.

[0164] The technical solution of this application will be clearly and completely described below with reference to the embodiments of this application. Unless otherwise specified, the reagents and raw materials used can be purchased commercially. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional methods and conditions, or conditions recommended by the manufacturer, or the product instructions shall be followed. Unless otherwise stated, all parts are parts by weight, and all percentages are weight percentages.

[0165] In this application, mass spectrometry was performed using a single quadrupole mass spectrometer manufactured by Waters Corporation, USA, and nuclear magnetic resonance was performed using a Bruker 400MHz nuclear magnetic resonance spectrometer (manufactured by Bruker GmbH, Germany).

[0166] Synthesis Examples

[0167] Example 1

[0168] Synthesis of Compound 61-2

[0169] Synthesis route:

[0170]

[0171] Synthesis method:

[0172] Synthesis of compound 1-iii:

[0173] Under a nitrogen atmosphere, 3-iodo-6-bromocarbazole (compound 1-i, 14.9 g, 40.0 mmol, 1 eq), compound 1-ii (9.3 g, 40.0 mmol, 1 eq), tetra(triphenylphosphine)palladium (462.2 mg, 0.8 mmol, 2% eq), and degassed tetrahydrofuran (100 mL) were added sequentially to a three-necked flask. After thorough mixing, potassium carbonate (50.0 mL, 2 M deionized water, 100.0 mmol, 2.5 eq) was added. The reaction system was heated to reflux and reacted under a nitrogen atmosphere for 5 hours. Thin-layer chromatography analysis showed that there was essentially no reactant residue. The reaction system was cooled to room temperature, and ethyl acetate (160 mL) was added. After standing, the phases separated. The organic phase was collected, and the aqueous phase was extracted with ethyl acetate (3 x 50 mL). The resulting organic phases were combined, dried over anhydrous magnesium sulfate, filtered, and the solvent was removed by vacuum distillation. The crude product was separated by rapid silica gel column chromatography (mobile phase was a mixture of n-hexane and ethyl acetate) to give compound 1-iii (14.4 g, yield 83.2%).

[0174] Synthesis of compound 1-v:

[0175] Under a nitrogen atmosphere, compound 1-iii (13.8 g, 32.0 mmol, 1 eq), 4-iodobiphenyl (compound 1-iv, 9.0 g, 32.0 mmol, 1 eq), palladium acetate (362.4 mg, 1.6 mmol, 5% eq), sodium tert-butoxide (6.2 g, 64.0 mmol, 2 eq), tri-tert-butylphosphine (3.2 mL, 1.0 M toluene solution, 3.2 mmol, 10% eq), and anhydrous toluene (100 mL) were added sequentially to a three-necked flask. After thorough mixing, the mixture was heated to reflux and reacted under a nitrogen atmosphere for 12 hours. Thin-layer chromatography analysis showed that there was essentially no reactant remaining. The reaction system was cooled to room temperature, and deionized water (100 mL) and ethyl acetate (150 mL) were added sequentially. The mixture was stirred for 5 minutes and then allowed to stand for separation. The organic phase was collected, and the aqueous phase was extracted with ethyl acetate (3 × 50 mL). The resulting organic phases were combined, dried over anhydrous magnesium sulfate, filtered, and the solvent was removed by vacuum distillation. The crude product was separated by rapid silica gel column chromatography (mobile phase was a mixture of n-hexane and ethyl acetate) to give compound 1-v (12.0 g, yield 64.2%).

[0176] Synthesis of compound 1-viii:

[0177] Following the synthetic method of compound 1-v, compound 1-viii was synthesized, except that the reaction substrates compound 1-iii and compound 1-iv were replaced by compounds 1-vi (3-bromocarbazole) and 1-vii (iodobenzene) in equal amounts, finally yielding compound 1-viii (6.4 g, yield 62.1%).

[0178] Synthesis of compound 1-ix:

[0179] Under a nitrogen atmosphere, compound 1-viii (6.4 g, 20.0 mmol, 1 eq), bipinnatrol borate (10.2 g, 40.0 mmol, 2 eq), and anhydrous 1,4-dioxane (80 mL) were added sequentially to a three-necked flask. After thorough mixing, potassium acetate (5.9 g, 60.0 mmol, 3 eq) and 1,1-bis(diphenylphosphine)diberberine palladium dichloride (146.3 mg, 0.2 mmol, 1% eq) were added sequentially. The mixture was stirred continuously and heated to reflux under a nitrogen atmosphere for 12 hours. The reaction system was then cooled to room temperature, and deionized water (80 mL) and ethyl acetate (120 mL) were added sequentially. The mixture was stirred for 5 minutes and then allowed to stand to separate into layers. The organic phase was collected, and the aqueous phase was extracted with ethyl acetate (3 x 40 mL). The combined organic phases were dried over anhydrous magnesium sulfate, filtered, and the solvent was removed by vacuum distillation to give compound 1-ix (7.2 g, 97.3% yield). The crude product obtained is used directly in the next reaction without further purification.

[0180] Synthesis of compound 61-2:

[0181] Compound 61-2 was synthesized following the method used for compound 1-iii, except that the reaction substrates compounds 1-i and 1-ii were replaced by compounds 1-v and 1-ix in equivalent amounts. The crude product was sequentially separated by silica gel column chromatography (using a hexane / toluene mixture as the mobile phase) and recrystallized in a toluene / ethanol mixture to obtain the target compound 61-2 (12.0 g, yield 80.3%). Using compound 1-i as the starting material, the overall yield of the three-step reaction was 42.9%. Mass spectrometry (m / z) = 747.3 [M+H]+.

[0182] 1H NMR (400MHz, DMSO-d6) data for compound 61-2: δ 9.14–9.08 (m, 2H), 8.10–8.07 (m, 1H), 8.06 (d, J = 7.5 Hz, 1H), 8.02 (d, J = 7.5 Hz, 1H), 7.75–7.72 (m, 2H), 7.69–7.59 (m, 10H), 7.56–7.49 (m, 3H), 7.46–7.34 (m, 8H), 7.28 (td, J = 7.5, 1.6 Hz, 1H), 7.18 (d, J = 7.6 Hz, 1H), 1.75 (s, 4H), 1.29 (s, 6H), 1.28 (s, 6H).

[0183] Example 2

[0184] Synthesis of compound 121-1:

[0185] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 44.5%. Mass spectrometry (m / z) = 811.3 [M+H]+.

[0186] Example 3

[0187] Synthesis of Compound 145-1

[0188] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 45.1%. Mass spectrometry (m / z) = 846.43 [M+H]+.

[0189] Example 4

[0190] Synthesis of Compound 122-1

[0191] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 40.5%. Mass spectrometry (m / z) = 879.46 [M+H]+.

[0192] 1H of compound 122-1 NMR (400MHz, DMSO-d6) data: δ9.15–9.09(m,2H),8.12–8.09(m,1H),8.07(d,J=7.5 Hz,1H),8.03(d,J=7.5Hz,1H),7.70–7.69(m,1H),7.67(dd,J=7.5,1.5Hz,1H),7. 65–7.60(m,9H),7.56(d,J=1.5Hz,2H),7.55–7.49(m,3H),7.47–7.35(m,10H),7 .32–7.24(m,2H),7.14(d,J=7.6Hz,1H),1.32(s,6H),1.30(s,6H),1.02(s,12H).

[0193] Example 5

[0194] Synthesis of Compound 97-2

[0195] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 45.8%. Mass spectrometry (m / z) = 853.44 [M+H]+.

[0196] Example 6

[0197] Synthesis of Compound 124-1

[0198] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details can be found in Example 1 for the synthesis of compounds 61-2. The overall yield of the three-step reaction was 41.8%. Mass spectrometry (m / z) = 923.40 [M+H]+.

[0199] Example 7

[0200] Synthesis of Compound 125-1

[0201] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, and 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 42.8%. Mass spectrometry (m / z) = 824.48 [M+H]+.

[0202] Example 8

[0203] Synthesis of compound 2-2:

[0204] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, and 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 40.2%. Mass spectrometry (m / z) = 899.43 [M+H]+.

[0205] ¹H NMR (400 MHz, DMSO-d6) data for compound 2-2: δ 9.14–9.08 (m, 2H), 8.11–8.08 (m, 1H), 8.05 (d, J = 7.5 Hz, 2H), 7.99–7.88 (m, 3H), 7.76–7.73 (m, 2H), 7.71–7.60 (m, 10H), 7.56–7.53 (m, 2H), 7.50–7.34 (m, 8H), 7.33–7.26 (m, 3H), 7.25 (d, J = 7.6 Hz, 1H), 2.08 (q, J = 12.9 Hz, 2H), 1.58 (s, 6H), 1.30 (s, 6H), 1.29 (s, 6H).

[0206] Example 9

[0207] Synthesis of Compound 126-1

[0208] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 40.7%. Mass spectrometry (m / z) = 879.37 [M+H]+.

[0209] Example 10

[0210] Synthesis of Compound 127-1

[0211] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 43.0%. Mass spectrometry (m / z) = 811.40 [M+H]+.

[0212] Example 11

[0213] Synthesis of Compound 128-1

[0214] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, and 1-vii respectively as Apart from the above, other details can be found in the synthesis of compounds 61-2 in Example 1. The overall yield of the three-step reaction was 43.3%. Mass spectrometry (m / z) = 829.51 [M+H]+.

[0215] Example 12

[0216] Synthesis of Compound 129-1

[0217] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details can be found in the synthesis of compounds 61-2 in Example 1. The overall yield of the three-step reaction was 45.5%. Mass spectrometry (m / z) = 851.39 [M+H]+.

[0218] 1H NMR (400MHz, DMSO-d6) data for compound 129-1: δ 9.14–9.08 (m, 2H), 8.08 (dd, J = 7.5, 1.6Hz, 1H), 8.06–8.01 (m, 4H), 7.84 (dd, J = 7.5, 1.5Hz, 1H), 7.80–7.76 (m, 2H), 7.70–7.40 (m, 18H), 7.37 (td, J = 7.5, 1.6Hz, 1H), 7.28 (td, J = 7.5, 1.6Hz, 1H), 7.14 (d, J = 7.5Hz, 1H), 7.03 (d, J = 1.5Hz, 1H), 1.31 (s, 6H), 1.29 (s, 6H), 1.04 (s, 6H).

[0219] Example 13

[0220] Synthesis of Compound 130-1

[0221] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details can be found in Example 1 for the synthesis of compounds 61-2. The overall yield of the three-step reaction was 44.3%. Mass spectrometry (m / z) = 823.40 [M+H]+.

[0222] Example 14

[0223] Synthesis of compound 91-3

[0224] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 43.6%. Mass spectrometry (m / z) = 929.48 [M+H]+.

[0225] Example 15

[0226] Synthesis of Compound 131-1

[0227] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 42.7%. Mass spectrometry (m / z) = 939.42 [M+H]+.

[0228] Example 16

[0229] Synthesis of Compound 129-2

[0230] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, and 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 43.4%. Mass spectrometry (m / z) = 927.46 [M+H]+.

[0231] ¹H NMR (400 MHz, DMSO-d6) data for compound 129-2: δ 9.16–9.06 (m, 2H), 8.06 (d, J = 3.4 Hz, 1H), 8.04 (d, J = 3.4 Hz, 1H), 7.85–7.81 (m, 1H), 7.76–7.59 (m, 12H), 7.55–7.40 (m, 11H), 7.38–7.30 (m, 4H), 7.14 (d, J = 7.5 Hz, 1H), 7.03 (d, J = 1.5 Hz, 1H), 1.59 (s, 6H), 1.31 (s, 6H), 1.29 (s, 6H), 1.04 (s, 6H).

[0232] Example 17

[0233] Synthesis of Compound 132-1

[0234] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details can be found in the synthesis of compounds 61-2 in Example 1. The overall yield of the three-step reaction was 41.6%. Mass spectrometry (m / z) = 983.52 [M+H]+.

[0235] Example 18

[0236] Synthesis of Compound 133-1

[0237] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 40.2%. Mass spectrometry (m / z) = 917.85 [M+H]+.

[0238] Example 19

[0239] Synthesis of Compound 134-1

[0240] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, and 1-vii respectively as Apart from the above, other details can be found in Example 1 for the synthesis of compounds 61-2. The overall yield of the three-step reaction was 42.1%. Mass spectrometry (m / z) = 853.44 [M+H]+.

[0241] Example 20

[0242] Synthesis of Compound 135-1

[0243] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 41.0%. Mass spectrometry (m / z) = 936.60 [M+H]+.

[0244] Example 21

[0245] Synthesis of Compound 136-1

[0246] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 44.0%. Mass spectrometry (m / z) = 839.34 [M+H]+.

[0247] Example 22

[0248] Synthesis of Compound 137-1

[0249] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 41.1%. Mass spectrometry (m / z) = 851.39 [M+H]+.

[0250] Example 23

[0251] Synthesis of Compound 138-1

[0252] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 42.8%. Mass spectrometry (m / z) = 873.41 [M+H]+.

[0253] 1H NMR (400MHz, DMSO-d6) data for compound 138-1: δ 9.15–9.08 (m, 2H), 8.05 (d, J = 7.4 Hz, 2H), 8.00–7.96 (m, 1H), 7.93–7.86 (m, 2H), 7.85–7.80 (m, 2H), 7.75–7.34 (m, 26H), 7.20 (d, J = 7.4 Hz, 1H), 1.75 (s, 4H), 1.29 (s, 6H), 1.28 (s, 6H).

[0254] Example 24

[0255] Synthesis of Compound 139-1

[0256] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details can be found in Example 1 for the synthesis of compounds 61-2. The overall yield of the three-step reaction was 43.3%. Mass spectrometry (m / z) = 843.52 [M+H]+.

[0257] Example 25

[0258] Synthesis of Compound 140-1

[0259] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details can be found in Example 1 for the synthesis of compounds 61-2. The overall yield of the three-step reaction was 43.0%. Mass spectrometry (m / z) = 844.42 [M+H]+.

[0260] Example 26

[0261] Synthesis of Compound 141-1

[0262] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, and 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 43.6%. Mass spectrometry (m / z) = 827.43 [M+H]+.

[0263] Example 27

[0264] Synthesis of Compound 142-1

[0265] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 42.7%. Mass spectrometry (m / z) = 863.39 [M+H]+.

[0266] Example 28

[0267] Synthesis of Compound 143-1

[0268] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 45.0%. Mass spectrometry (m / z) = 877.44 [M+H]+.

[0269] 1H NMR (400MHz, DMSO-d6) data for compound 143-1: δ 9.15–9.08 (m, 2H), 8.12–8.07 (m, 3H), 8.05 (d, J = 7.4 Hz, 1H), 7.85–7.78 (m, 3H), 7.70–7.65 (m, 3H), 7.64–7.33 (m, 17H), 7.28 (td, J = 7.5, 1.6 Hz, 1H), 7.15 (d, J = 7.5 Hz, 1H), 7.01 (d, J = 1.5 Hz, 1H), 1.60 (s, 6H), 1.31 (s, 6H), 1.29 (s, 6H), 1.04 (s, 6H).

[0270] Example 29

[0271] Synthesis of Compound 144-1

[0272] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details regarding the synthesis of compounds 61-2 in Example 1 can be found in Example 1. The overall yield of the three-step reaction was 43.7%. Mass spectrometry (m / z) = 985.54 [M+H]+.

[0273] Example 30

[0274] Synthesis of Compound 91-2

[0275] In addition to referring to the raw material or intermediate compounds 1-i, 1-ii, 1-iv, 1-vi, 1-vii respectively as Apart from the above, other details can be found in Example 1 for the synthesis of compounds 61-2. The overall yield of the three-step reaction was 42.4%. Mass spectrometry (m / z) = 853.44 [M+H]+.

[0276] 1H NMR (400MHz, DMSO-d6) data for compound 91-2: δ 9.15–9.10 (m, 2H), 8.55–8.52 (m, 1H), 8.08–8.01 (m, 2H), 7.93–7.90 (m, 1H), 7.80 (dd, J = 7.5, 1.5Hz, 1H), 7.75–7.34 (m, 23H), 7.29 (d, J = 1.5Hz, 1H), 7.14 (d, J = 7.6Hz, 1H), 1.32 (s, 6H), 1.30 (s, 6H), 1.02 (s, 12H).

[0277] Device Examples

[0278] All compounds used in the device embodiments of this application have undergone sublimation purification, and their purity is greater than 99.98%. The following embodiments illustrate the use of compounds of this application as electron blocking layer materials or light-emitting layer host materials in green OLED devices.

[0279] Example 31

[0280] refer to Figure 1 This embodiment fabricates a green bottom-emitting organic electroluminescent device, and the fabrication process includes the following steps:

[0281] A transparent ITO film (150 nm thick) is formed on a glass substrate 101 by magnetron sputtering to obtain the first electrode as the anode 102.

[0282] A mixture of compound M1 and compound M2 is deposited on the surface of anode 102 as hole injection layer 103, with a mixing ratio of 3:97 (mass ratio) and a thickness of 10 nm.

[0283] Subsequently, compound M2 (100 nm thick) and compound M3 (40 nm thick) were sequentially deposited on the surface of hole injection layer 103 to obtain hole transport layer 104 and electron blocking layer 105, respectively.

[0284] Next, on the surface of the electron blocking layer 105, compounds 61-2, M4 and M5 of this application are co-deposited in a mass ratio of 45:45:10 to form an organic light-emitting layer 106 (thickness 40 nm).

[0285] Subsequently, compound M6 is sequentially deposited on the surface of organic light-emitting layer 106 to form hole blocking layer 107 (thickness 10 nm), and compound M7 and LiQ in a mixing ratio of 4:6 (mass ratio) form electron transport layer 108 (thickness 30 nm).

[0286] Finally, magnesium (Mg) and silver (Ag) are mixed and deposited on the surface of electron transport layer 108 at a vapor deposition rate of 1:9 to form a second electrode with a thickness of 10 nm as cathode 109, thus completing the fabrication of organic electroluminescent device.

[0287] The structural formulas of the compounds M1 to M7 and LiQ are shown in Table 1.

[0288] Table 1 Structural formulas of compounds M1-M7 and LiQ

[0289]

[0290] Examples 32-50

[0291] Electroluminescent devices were fabricated using the same method as in Example 31, except that compounds listed in Table 2 were used instead of compounds 61-2 as the main material when forming the light-emitting layer.

[0292] Comparative Examples 1-3

[0293] Except that compounds C1, C2, and C3 were used to replace compound 61-2 as the main material when forming the light-emitting layer, the organic electroluminescent device was fabricated using the same method as in Example 1.

[0294]

[0295] The operating voltage and current efficiency of the organic electroluminescent devices prepared in Examples 31-50 and Comparative Examples 1-3 were calculated using a computer-controlled Keithley 2400 testing system (test current 20 mA / cm²). 2 The lower the operating voltage, the lower the power consumption.

[0296] The LT95 lifetime of the device under dark conditions was tested using a Flustar lifetime measurement system equipped with a power supply and a photodiode as detection units (test conditions: constant current 20mA / cm). 2 LT95 refers to the time required for the brightness to decrease from its initial value to 95%. The test results are shown in Table 2.

[0297] Table 2. Device performance test results of Examples 31-50 and Comparative Examples 1-3

[0298]

[0299]

[0300] As shown in Table 2, compared with the organic electroluminescent devices of Comparative Examples 1 to 3, the performance of the organic electroluminescent devices of Examples 31 to 50 is improved. The current efficiency and device lifespan of the devices are significantly improved, and they also have a lower operating voltage, which is far below the requirements for use.

[0301] Example 51

[0302] refer to Figure 1 This embodiment fabricates a green bottom-emitting organic electroluminescent device, and the fabrication process includes the following steps:

[0303] A transparent ITO film (150 nm thick) is formed on a glass substrate 101 by magnetron sputtering to obtain the first electrode as the anode 102.

[0304] A mixture of compound M1 and compound M2 is deposited on the surface of anode 102 as hole injection layer 103, with a mixing ratio of 3:97 (mass ratio) and a thickness of 10 nm.

[0305] Subsequently, compound M2 (100 nm thick) and compound 121-1 (40 nm thick) of this application were sequentially deposited on the surface of hole injection layer 103 to obtain hole transport layer 104 and electron blocking layer 105, respectively.

[0306] Next, on the surface of the electron blocking layer 105, compounds M4-B and M5 are co-deposited at a mass ratio of 90:10 to form an organic light-emitting layer 106 (40 nm thick).

[0307] Subsequently, compound M6 is sequentially deposited on the surface of organic light-emitting layer 106 to form hole blocking layer 107 (thickness 10 nm), and compound M7 and LiQ in a mixing ratio of 4:6 (mass ratio) form electron transport layer 108 (thickness 30 nm).

[0308] Finally, magnesium (Mg) and silver (Ag) are mixed and deposited on the surface of electron transport layer 108 at a vapor deposition rate of 1:9 to form a second electrode with a thickness of 10 nm as cathode 109, thus completing the fabrication of organic electroluminescent device.

[0309] The chemical structures of compounds M1-M2, M5-M7 and LiQ are as described above, and the chemical structure of compound M4-B is shown below:

[0310]

[0311] Examples 52-60

[0312] Electroluminescent devices were fabricated using the same method as in Example 51, except that compound 121-1 was replaced with the compounds listed in Table 3 when forming the electron blocking layer.

[0313] Comparative Examples 4-5

[0314] Except that compounds 121-1 were replaced with compounds C4 and C5 respectively when forming the electron blocking layer, the organic electroluminescent device was fabricated using the same method as in Example 51.

[0315]

[0316] The operating voltage, current efficiency, and LT95 lifetime of the organic electroluminescent devices fabricated in Examples 51-60 and Comparative Examples 4 and 5 were tested using the aforementioned method. The test results are shown in Table 3.

[0317] Table 3. Device performance test results of Examples 51-60 and Comparative Examples 4-5

[0318]

[0319] As shown in Table 3, when organic electroluminescent devices are prepared using the compounds of this application as electron blocking layers, the current efficiency and lifespan of the devices can be significantly improved compared with existing compounds, while also having a lower operating voltage.

[0320] The above description of the embodiments is intended to enable those skilled in the art to understand and apply this application. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, this application is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of this application without departing from the scope and spirit of this application are within the scope of this application.

Claims

1. A carbazole compound, characterized in that, The carbazole compounds are represented by any of the following structural formulas from Formula 1 to Formula 148: ； in: n2 is an integer from 0 to 7; L2 is selected from the following groups, either single-bonded or substituted or unsubstituted: phenylene, naphthylene, fluorene, dibenzofuranyl, dibenzothiopheneyl; Ar2 is selected from the following groups, whether substituted or unsubstituted: phenyl, naphthyl, diphenyl, fluorenyl, dibenzofuranyl, dibenzothiopheneyl; The substituents of L2 and Ar2 may be the same or different from each other, and are each independently selected from deuterium, halogen groups, cyano, C1~C10 alkyl, C3~C10 cycloalkyl, C1~C10 alkoxy, C6~C20 aryl, and C3~C20 heteroaryl. R2 is selected from deuterium, the structure shown in formula (1a) or formula (1b), or the structure in which at least one hydrogen atom in the structure shown in formula (1a) or formula (1b) is substituted with deuterium, or any two adjacent R2s are bonded to form a benzene ring, or the following groups are substituted or unsubstituted: phenyl, naphthyl, fluorenyl, dibenzofuranyl, dibenzothiopheneyl, wherein the substituents of the group are selected from deuterium, halogen groups, cyano, C1-C5 alkyl, C1-C6 cycloalkyl, adamantyl or phenyl; Equation (1a) is selected from the following structures: ； Equation (1b) is selected from the following structures: ； * represents a connection point.

2. A carbazole compound, characterized in that, The carbazole compounds are selected from the following group: 。 3. An organic layer, characterized in that, Including the carbazole compounds as described in claim 1 or 2.

4. The use of the carbazole compound of claim 1 or 2 and / or the organic layer of claim 3 in organic electroluminescent devices.

5. An organic electroluminescent device, characterized in that, It includes a first electrode, a second electrode, and the organic layer of claim 3, wherein the organic layer includes at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, and an electron transport layer.

6. A display device, characterized in that, Including the organic electroluminescent device as described in claim 5.

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