Carbazole compound, intermediate, composition and organic electroluminescent device

Abstract

The invention provides a carbazole compound, an intermediate, a composition and an organic electroluminescent device, and belongs to the technical field of organic electroluminescent materials. The carbazole compound has a structure as shown in a formula I. Through structural design of the carbazole compound, the carbazole compound with excellent performance is prepared, and the organic light-emitting device prepared by taking the carbazole compound as a material of a light-emitting layer has relatively high current efficiency, relatively long service life and relatively low driving voltage.

Description

Technical Field

[0001] The invention belongs to the technical field of organic electroluminescent materials, and in particular relates to a carbazole compound, an intermediate, a composition and an organic electroluminescent device. Background Art

[0002] Compared with other flat panel displays (for example, liquid crystal displays (LCDs), plasma display panels (PDPs), field emission displays (FEDs), etc.), organic electroluminescent devices (OLEDs) have a simpler structure, various processing advantages, higher brightness, excellent viewing angle characteristics, faster response speeds, and lower driving voltages. Therefore, they have been fully developed to be used as light sources for flat panel displays (for example, wall-mounted TVs, etc.), or as backlight units for displays, illuminators, billboards, etc.

[0003] The structure of an organic electroluminescent device specifically consists of an anode, a cathode, and an organic layer between them. To improve the efficiency and stability of organic electroluminescent elements, the organic material layer can be composed of multiple layers of different materials. To meet the increasing demands for OLED devices, the field urgently needs to develop a wider variety of materials to improve OLED device performance in terms of current efficiency, lifespan, and other aspects. Summary of the Invention

[0004] To address the shortcomings of the prior art, the present invention provides a carbazole compound, intermediate, composition, and organic electroluminescent device. By designing the structure of the carbazole compound, the present invention produces a carbazole compound with excellent performance. Organic electroluminescent devices prepared using the carbazole compound as the material for the light-emitting layer exhibit high current efficiency, a long lifespan, and a low driving voltage.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a carbazole compound having a structure shown in the following formula I:

[0007]

[0008] wherein Ar1, Ar2, and Ar3 are each independently selected from at least one of a C6-C20 aryl group or a C6-C20 heteroaryl group;

[0009] Ar is selected from at least one of a C6-C20 aryl group or a C6-C20 heteroaryl group;

[0010] At least one hydrogen atom in the compound of formula I is substituted by a group having the structure represented by formula I-1, ring A represents a C3-C12 cycloalkyl group, and R is selected from a C1-C12 alkyl group;

[0011] The remaining hydrogen atoms in the compounds of formula I may each independently be replaced by a deuterium atom.

[0012] The present invention designs carbazole compounds to prepare excellent performance carbazole compounds with relatively suitable HOMO and LUMO energy levels and good molecular film-forming properties. The organic electroluminescent device prepared by using the carbazole compounds as the material of the light-emitting layer has high current efficiency, long life and low driving voltage.

[0013] In the present invention, C1-C12 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12.

[0014] C6-C20 can be C6, C10, C12, C15, C18 or C20, etc.

[0015] C3-C12 can be C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12.

[0016] In the present invention, "-D" represents a deuterium atom. Unless otherwise indicated, H and hydrogen therein represent "protium", and the same shall apply hereinafter.

[0017] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0018] As a preferred technical solution of the present invention, the C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, butyl, pentyl, methylcyclopentyl, hexyl, methylcyclohexyl, heptyl, octyl, adamantyl, bicyclo[2.2.1]heptyl or bicyclo[2.2.2]octyl.

[0019] Preferably, the C3-C12 cycloalkyl group is selected from any one of cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and cyclononyl groups.

[0020] Preferably, the C6-C20 aryl group is selected from any one of phenyl, naphthyl, biphenyl and 9,9-dimethylfluorenyl.

[0021] Preferably, the C6-C20 heteroaryl group is selected from any one of a carbazolyl group, a dibenzofuranyl group or a dibenzothiophenyl group.

[0022] As a preferred technical solution of the present invention, Ar1, Ar2, and Ar3 are each independently selected from at least one of phenyl, naphthyl, biphenyl, dibenzofuranyl, and dibenzothiophenyl.

[0023] Preferably, any two of Ar1, Ar2, and Ar3 are selected from phenyl groups, and the other one is selected from at least one of phenyl, naphthyl, biphenyl, dibenzofuranyl, and dibenzothiophenyl groups.

[0024] As a preferred technical solution of the present invention, Ar is selected from any one of phenyl, naphthyl, biphenyl, 9,9-dimethylfluorenyl, dibenzofuranyl, phenyl-substituted dibenzofuranyl, dibenzothiophenyl, phenyl-substituted dibenzothiophenyl, carbazolyl, and phenyl-substituted carbazolyl.

[0025] As a preferred technical solution of the present invention, the ring A represents any one of cyclopentanyl, cyclohexanyl, cycloheptyl, cyclooctyl and cyclononanyl.

[0026] Preferably, R is selected from any one of methyl, ethyl, n-propane, isopropane, n-butyl, isobutyl, tert-butyl, cyclopentyl and cyclohexyl.

[0027] As a preferred technical solution of the present invention, the carbazole compound has a structure shown in the following formula I-1 or formula I-2:

[0028]

[0029] Wherein, Ar1, Ar2, Ar3, Ar have the same definitions as above;

[0030] At least one H atom in the compound of formula I-1 or formula I-2 is substituted by a group having formula I-1;

[0031] The remaining hydrogen atoms in the compound of formula I-1 and the compound of formula I-2 may each independently be replaced by a deuterium atom.

[0032] Preferably, the carbazole compound has a structure as shown in the following formula I-11 or formula I-2:

[0033]

[0034] Wherein, Ar1, Ar2, Ar3, Ar have the same definitions as above;

[0035] In the compound of formula I-1 and the compound of formula I-2, y is each independently selected from 0 or 1;

[0036] The hydrogen atoms in the compound of formula I-1 and the compound of formula I-2 may each independently be replaced by a deuterium atom.

[0037] As a preferred technical solution of the present invention, the carbazole compound is selected from any one of the following substituted or unsubstituted compounds:

[0038]

[0039]

[0040] The substitution means that the hydrogen atoms in the above carbazole compound can be independently replaced by deuterium atoms. Preferably, the carbazole compound is selected from any one of the following compounds:

[0041]

[0042] It should be noted that the present invention does not have any special restrictions on the preparation method of the carbazole compound, and all commonly used preparation methods in the art are applicable.

[0043] In a second aspect, the present invention further provides an intermediate, comprising the following compound:

[0044]

[0045] The intermediate is used to prepare the carbazole compound described above.

[0046] In a third aspect, the present invention provides a composition comprising at least a first component and a second component, wherein the first component comprises at least one carbazole compound according to the first aspect, and the second component comprises at least one compound having a structure represented by the following formula II:

[0047]

[0048] wherein R1, R2, R3, and R4 are each independently selected from a C6-C20 aryl group or a C6-C20 heteroaryl group;

[0049] m, o, and p are each independently selected from an integer between 0 and 4;

[0050] n is selected from an integer between 0 and 3;

[0051] The hydrogen atoms in the compound of formula II can be replaced independently by deuterium atoms (-D), -F, -CN, C1-C12 alkyl, C1-C12 alkoxy, triphenylsilyl ( The dotted line indicates the connection site, the same below), triphenylmethyl The compound is substituted with at least one of a C6-C20 aryl group or a C6-C20 heteroaryl group.

[0052] In the compound of formula II, C1-C12 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12.

[0053] C6-C20 can be C6, C10, C12, C15, C18 or C20, etc.

[0054] Preferably, the C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, butyl, pentyl, methylcyclopentyl, hexyl, methylcyclohexyl, heptyl, octyl, adamantyl, bicyclo[2.2.1]heptyl or bicyclo[2.2.2]octyl.

[0055] Preferably, the C1-C12 alkoxy group is selected from any one of methoxy, ethoxy, propoxy, butoxy, pentyloxy or hexyloxy.

[0056] Preferably, the C6-C20 aryl group is selected from any one of phenyl, naphthyl, biphenyl and 9,9-dimethylfluorenyl.

[0057] Preferably, the C6-C20 heteroaryl group is selected from any one of a carbazolyl group, a dibenzofuranyl group or a dibenzothiophenyl group.

[0058] As a preferred technical solution of the present invention, m+n+o+p=0.

[0059] As a preferred technical solution of the present invention, m+n=0, o+p=1.

[0060] As a preferred technical solution of the present invention, m+n=0, o=0, and p=1.

[0061] As a preferred technical solution of the present invention, m+n=0, o=1, and p=0.

[0062] As a preferred technical solution of the present invention, m+n=0, o=0, and p=2.

[0063] As a preferred technical solution of the present invention, m+n=0, o=2, and p=0.

[0064] As a preferred technical solution of the present invention, m+n=0, o=1, and p=1.

[0065] As a preferred technical solution of the present invention, m=1, n=1, o=0, and p=1.

[0066] As a preferred technical solution of the present invention, m=1, n=o=0, and p=1.

[0067] As a preferred technical solution of the present invention, R1, R2, R3, and R4 are each independently selected from any one of phenyl, naphthyl, biphenyl, 9,9-dimethylfluorenyl, dibenzofuranyl, dibenzothiophenyl, and carbazolyl.

[0068] Preferably, R1, R2, and R3 are each independently selected from any one of phenyl, naphthyl, or biphenyl, and more preferably phenyl.

[0069] Preferably, R4 is selected from any one of phenyl, naphthyl, biphenyl, 9,9-dimethylfluorenyl, dibenzofuranyl, dibenzothiophenyl, and carbazolyl.

[0070] As a preferred technical solution of the present invention, the hydrogen atoms in the compound of formula II can each independently be replaced by at least one of a deuterium atom (-D), -F, -CN, a methyl group, an ethyl group, a propyl group, a tert-butyl group, a methoxy group, an ethoxy group, a propoxy group, a phenyl group, a naphthyl group, a biphenyl group, a carbazolyl group or a triphenylsilyl group.

[0071] As a preferred technical solution of the present invention, the compound of formula II is selected from any one of the following substituted or unsubstituted compounds:

[0072]

[0073]

[0074] The substitution means that the hydrogen atoms in the carbazole compounds can be independently replaced by deuterium atoms.

[0075] Preferably, the compound of formula II is selected from any one of the following compounds:

[0076]

[0077] It should be noted that the present invention does not have any special limitations on the preparation method of the compound of formula II, and any commonly used preparation method in the art is applicable.

[0078] In a fourth aspect, the present invention provides an organic electroluminescent device, comprising an anode, a cathode, and an organic thin film layer disposed between the anode and the cathode;

[0079] The material of the organic thin film layer includes the carbazole compound described in the first aspect or the composition described in the third aspect.

[0080] Preferably, the organic thin film layer includes a light-emitting layer, and the main material of the light-emitting layer includes the carbazole compound described in the first aspect or the composition described in the third aspect.

[0081] Preferably, the light-emitting layer is a phosphorescent light-emitting layer.

[0082] As a preferred technical solution of the present invention, the organic electroluminescent device is a blue organic electroluminescent device.

[0083] The luminescent layer of the present invention includes a luminescent layer host material and a dopant material, wherein the dopant material is also called a dye or a phosphorescent luminescent material. The luminescent layer host material can be a single compound or a mixture of two or more compounds.

[0084] The light-emitting layer includes a phosphorescent light-emitting layer, and the phosphorescent light-emitting layer includes a green phosphorescent light-emitting layer, a red phosphorescent light-emitting layer, a yellow phosphorescent light-emitting layer, and a blue phosphorescent light-emitting layer.

[0085] The volume percentage of the main material in the phosphorescent light-emitting layer is 60% to 99.9% (for example, it can be 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99.9%, etc.), preferably 70% to 99.5%, and more preferably 85% to 95%.

[0086] In the present invention, the doping material for the light-emitting layer may be a phosphorescent material, which is also called a triplet light-emitting material and refers to a substance that emits light from a triplet excited state. The specific choice of phosphorescent material in the present invention is not particularly limited, and any doping material for the light-emitting layer commonly used in the art is applicable, including but not limited to compounds having a structure as shown in Formula PD:

[0087]

[0088] wherein M is selected from any one of Ir, Pt, Pd, Os, Ti, Zr, Hf, Eu, Tb, Tm, Cu, or Au;

[0089] Y1-Y4 are each independently selected from carbon or nitrogen;

[0090] Y1 and Y2 can be connected by a single bond or a double bond, and Y3 and Y4 can be connected by a single bond or a double bond;

[0091] Cy1 and Cy2 are each independently selected from any one of phenyl, naphthyl, fluorenyl, spirofluorenyl, indenyl, pyrrolyl, thienyl, furyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, quinolyl, isoquinolyl, benzoquinolyl, quinoxalinyl, quinazolinyl, carbazolyl, benzimidazolyl, benzofuranyl, benzothiophenyl, isobenzothiophenyl, benzimidazolyl, benzoxazolyl, triazolyl, tetrazolyl, oxadiazolyl, triazinyl, dibenzofuranyl, dibenzothiophenyl, N-heterocarbazolyl, N-heterodibenzofuranyl, wherein Cy1 and Cy2 may be optionally linked to each other via a single bond or an organic linking group;

[0092] Any two ligands of M, or more than two ligands, may be connected by a single bond or a double bond, or may be bridged by O or S, or may be connected by any chemical group or chemical structure to form a structural form that conforms to chemical principles;

[0093] R 91 and R 92Each is independently selected from -H, -D, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazine, hydrazone, carboxylic acid, carboxylate, sulfonic acid, sulfonate, phosphoric acid, phosphate, -SF5, substituted or unsubstituted C1-C60 (for example, C1, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) alkyl, substituted or unsubstituted C2-C6 C2, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) alkenyl, substituted or unsubstituted C2-C60 (for example, C2, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) alkynyl, substituted or unsubstituted C1-C60 (for example, C1, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) C2-C10 (for example, C2, C3, C4, C5, C6, C7, C8, C9 or C10) heterocycloalkyl, substituted or unsubstituted C6-C60 (for example, C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60) aryl, substituted or unsubstituted C6-C60 (for example, C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60) aryl, substituted or unsubstituted C6-C60 ( For example, it can be any one of C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60) aryloxy, substituted or unsubstituted C6-C60 (for example, it can be C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60) arylthio, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, and substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group.

[0094] a1 and a2 are each independently an integer selected from 1 to 5, for example, 1, 2, 3, 4 or 5;

[0095] b is an integer selected from 0-4, for example, 0, 1, 2, 3 or 4;

[0096] a is selected from 1, 2 or 3;

[0097] L1 is a monovalent organic ligand, a divalent organic ligand or a trivalent organic ligand.

[0098] Preferably, the compound of formula PD is selected from any one of the following compounds:

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105] In the present invention, the organic thin film layer includes a hole layer, and the hole layer includes a hole injection layer, a hole transport layer and an electron blocking layer.

[0106] The hole injection layer material includes a P-type dopant. The P-type dopant coexists with the hole injection layer material in the OLED device and is capable of oxidizing the hole injection layer material, thereby acting as an electron acceptor and promoting the migration of holes from the hole injection layer toward the anode. In the present invention, the difference between the absolute value of the LUMO of the P-type dopant and the absolute value of the HOMO of the hole layer material is greater than -0.2V, preferably greater than -0.1eV, more preferably greater than 0eV, more preferably greater than 0.1eV, and even more preferably greater than 0.2eV.

[0107] The P-type dopant is present in the hole injection layer at a volume percentage of 1% to 10% (e.g., 1%, 2%, 4%, 6%, 8%, or 10%). In the present invention, there is no particular limitation on the type of the P-type dopant. For example, compounds D-1 to D-13 disclosed in CN113728453A or compounds HI-1 to HI-9 described below may be used:

[0108]

[0109]

[0110] In the present invention, the hole layer material (including the hole injection layer, the hole transport layer and the electron blocking layer) has a structure shown in the following formula HT-GH4:

[0111]

[0112] Among them, L 41 is selected from a single bond, a C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40, etc.) aryl, or a C6-C20 (e.g., C6, C8, C10, C12, C16, or C20, etc.) heteroaryl;

[0113] Ar 41 、Ar42 Each is independently selected from C6-C40 (for example, C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) aryl, C6-C20 (for example, C6, C8, C10, C12, C16 or C20, etc.) heteroaryl;

[0114] X is selected from CR 41 R 42 or NR 43 , where R 41 、R 42 、R 43 are each independently selected from any one of substituted or unsubstituted phenyl (the substituted substituent is selected from C1-C6 (for example, C1, C2, C3, C4, C5 or C6) alkyl, C1-C6 (for example, C1, C2, C3, C4, C5 or C6) alkoxy, dibenzofuranyl), naphthyl, triphenylene, fluoranthenyl, 9,9-dimethylfluorenyl, biphenyl, substituted or unsubstituted dibenzofuranyl (the substituted substituent is phenyl), substituted or unsubstituted dibenzothiophenyl (the substituted substituent is phenyl), dibenzofuran-substituted thienyl, C1-C6 (for example, C1, C2, C3, C4, C5 or C6) alkyl, R 41 、R 42 They can be linked to form rings via single bonds.

[0115] In the present invention, the hole layer material (including the hole injection layer, the hole transport layer and the electron blocking layer) further includes a compound having a structure as shown in the following formula IA or a compound having a structure as shown in the following formula IB:

[0116]

[0117] wherein L is selected from any one of a C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40) arylene group, a dibenzofuranyl group, or a dibenzothiophenyl group;

[0118] m is selected from an integer between 0 and 4 (for example, 0, 1, 2, 3 or 4), and n is selected from 0 or 1;

[0119] Ar is selected from any one of triphenylene, fluoranthenylene, dibenzofuranylene or dibenzothiophenylene;

[0120] Ar1 and Ar2 are each independently selected from any one of a C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40, etc.) aryl group, a dibenzofuranyl group, or a dibenzothiophenyl group;

[0121] Ar1 and Ar, Ar2 and Ar, and Ar1 and Ar2 can each independently be connected or bridged by a single bond, O, S, CR1R2, or NR.

[0122] R, R1, and R2 are each independently selected from any one of a C1-C20 (e.g., C1, C2, C4, C6, C8, C10, C12, C14, C16, C18, or C20) alkyl group, a C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40) aryl group, a dibenzofuranyl group, or a dibenzothiophenyl group;

[0123] The hydrogen atoms in the compound of formula IB and the compound of formula IA may each independently be replaced by at least one of -F, -CN, -D (deuterium atom), C1-C6 alkyl, C1-C6 alkoxy, phenyl, biphenyl, naphthyl, phenanthrenyl, anthracenyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, triphenylene, fluoranthenyl, pyrenyl, perylenyl, spirofluorenyl, indenofluorenyl or hydrogenated benzanthryl.

[0124] Preferably, Ar is a fluoranthenyl group, and m+n>1.

[0125] Preferably, H in the compound of formula IB and the compound of formula IA can be replaced by at least one of -F, -CN, -D, C1-C3 alkyl (for example, methyl, ethyl or propyl), C1-C3 alkoxy (for example, methoxy, ethoxy or propoxy), phenyl, biphenyl, triphenylene, and fluoranthenyl.

[0126] Preferably, L, Ar1, and Ar2 are each independently selected from at least one of phenyl, biphenyl, naphthyl, phenanthryl, anthracenyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, triphenylene, fluoranthenyl, pyrenyl, perylene, spirofluorenyl, indenofluorenyl, and hydrogenated benzanthryl.

[0127] Preferably, the compound of formula IB is selected from any one of the following compounds:

[0128]

[0129]

[0130] In the OLED device provided by the present invention, the hole layer material, in addition to the compound of formula HT-GH4, the compound of formula IB, and the compound of formula IA, may also include conventional hole materials in the art, without particular limitation. Exemplary examples include, but are not limited to, triarylamine compounds or carbazole compounds. Triarylamine compounds or carbazole compounds containing more than 3 N atoms are preferred, because the HOMO of triarylamine compounds or carbazole compounds containing more than 3 N atoms is higher (the absolute value is smaller), and they are more suitable for use as hole injection layer materials. Triarylamine compounds or carbazole compounds containing 2 or 1 N atoms can be used as hole transport layer materials. Some compounds or carbazole compounds containing 1 N atom, if they have a higher LUMO, can also be used as electron blocking layer materials.

[0131] The triarylamine compound or the carbazole compound is used as the hole layer material, and the hole layer material includes the following structure:

[0132]

[0133] Among them, Ar 601 ~Ar 609 Each independently selected from a substituted or unsubstituted C6-C40 (for example, C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) aryl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted naphthobenzofuranyl group, a substituted or unsubstituted naphthobenzothiophenyl group, a substituted or unsubstituted dinaphthofuranyl group, or a substituted or unsubstituted dinaphthothiophenyl group;

[0134] And Ar 601 ~Ar 609 Ar atoms adjacent to or connected to the same N atom 601 ~Ar 609 , can be connected by single key or through O, S, CR 701 R 702 NR 703 bridging;

[0135] R 701 、R 702 、R 703 is selected from C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40, etc.) aromatic groups, C6-C20 (e.g., C6, C8, C10, C12, C16, or C20, etc.) heteroaryl groups, C1-C6 (e.g., C1, C2, C3, C4, C5, or C6) alkyl groups, and R 701 、R702 Can connect via one-touch.

[0136] A hole-blocking layer (HBL) can confine holes and / or excitons within the emitting layer (EL) to improve device current efficiency and lifetime. Compared to the EL material closest to the HBL interface, the HBL material has a lower HOMO (larger absolute value) and / or higher triplet energy.

[0137] The electron transport layer (ETL) may include a material capable of transporting electrons. The electron transport layer may be intrinsic (undoped) or doped, and doping may be used to enhance conductivity. In the present invention, there is no particular restriction on the ETL material, and any metal complex or organic compound may be used as long as it can transport electrons. Generally, the electron transport layer material contains the following structural fragments: at least one of a pyridine structure, a pyrimidine structure, a triazine structure, a benzimidazole structure, a benzoxazole structure, a benzothiazole structure, an N-naphthalene structure, an N-heterophthalene structure, an N-heterocarbazole structure, an N-heterodibenzofuran structure, and an N-heterodibenzothiophene structure.

[0138] In the present invention, there is no particular limitation on the electron transport layer materials, which exemplarily include but are not limited to:

[0139]

[0140]

[0141]

[0142] In the present invention, the cathode material is a metal with a low work function (e.g., alkaline earth metals, alkali metals, main group metals, or lanthanides (e.g., Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.)), a metal alloy composed of multiple metals (e.g., an alloy composed of an alkali metal or alkaline earth metal and silver, e.g., an alloy composed of magnesium and silver), or a multilayer structure. If the cathode material is a multilayer structure, in addition to the metals mentioned above, other metals with relatively high work functions, such as Ag or Al, may also be used. In this case, combinations of these metals are typically used, such as Ca / Ag, Mg / Ag, or Ba / Ag.

[0143] Alternatively, a thin intermediate layer of a material with a high dielectric constant may be introduced between the metal cathode and the organic semiconductor to form a multilayer structure. The material with a high dielectric constant may also be referred to as an electron injection material, and may be fluorides of alkali metals or alkaline earth metals, and corresponding oxides or carbonates (e.g., LiF, Li2O, BaF2, MgO, NaF, CsF, Cs2CO3, etc.) or lithium quinoline (LiQ).

[0144] Compared with the prior art, the present invention has the following beneficial effects:

[0145] The present invention designs the structure of carbazole compounds to prepare carbazole compounds with excellent performance. The organic electroluminescent device prepared by using the carbazole compounds as the material of the light-emitting layer has high current efficiency, long life and low driving voltage. DETAILED DESCRIPTION

[0146] For the convenience of understanding the present invention, the present invention is given below with examples. It should be understood by those skilled in the art that the examples are only for the purpose of helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0147] Preparation Example 1

[0148] This preparation example provides intermediate M1 and its synthesis method, the synthesis method is as follows:

[0149]

[0150] Under nitrogen protection, 3-iodo-tert-butylbenzene (2.6 g), 4-bromocarbazole (2.5 g), anhydrous potassium carbonate (2.5 g), o-dichlorobenzene (30 mL), DMF (6 mL), cuprous oxide (0.1 g), o-phenanthroline (0.2 g) were added to a three-necked flask, first reacted at 80 ° C for 4 hours, then heated to 120 ° C for 6 hours, cooled, filtered to remove insoluble matter, washed with water, separated, the organic layer was washed with water until neutral, dried over anhydrous magnesium sulfate, filtered to remove the desiccant, concentrated to dryness, and crystallized with ethanol to obtain intermediate M1 (2.1 grams).

[0151] The mass spectrometry of the intermediate M1 showed that its mass-to-charge ratio (m / z) was 377.08.

[0152] Preparation Example 2-3

[0153] Preparation Examples 2-3 respectively provide an intermediate and a synthesis method thereof. The synthesis method of the corresponding intermediate refers to the preparation method of intermediate M1. Raw materials 1 and 2 are reacted to prepare the corresponding intermediate, and the mass spectrum of the prepared intermediate is measured to record its mass-to-charge ratio m / z. Details are shown in Table 1 below:

[0154] Table 1

[0155]

[0156] Synthesis Example 1 Synthesis of Compound P1

[0157] This synthesis example provides compound P1 and its synthesis method, the synthesis method is as follows:

[0158]

[0159] Under a nitrogen atmosphere, dry toluene (50 mL), intermediate M1 (3.8 g), carbazole (1.7 g), Pd(dba)2 (bis(dibenzylideneacetonepalladium, 0.1 g), 0.8 g of a 10% mass percentage tri-tert-butylphosphine toluene solution (the mass of tri-tert-butylphosphine is 0.08 g) and sodium tert-butoxide (1.2 g) were added to a three-necked flask, heated to reflux temperature, reacted for 8 h, cooled to room temperature, and separated by adding water. The organic layer was then washed with water until neutral, dried with magnesium sulfate, filtered to remove the magnesium sulfate, concentrated to dryness, and crystallized from a mixed solvent of toluene and ethanol to obtain compound P1 (3.8 g).

[0160] Compound P1 was subjected to mass spectrometry detection: its mass-to-charge ratio (m / z) was measured to be 464.23.

[0161] Synthesis Examples 2-5

[0162] Synthesis Examples 2-5 provide a compound and a synthesis method thereof, respectively. The synthesis method of the compound refers to the preparation method of compound P1, and the corresponding raw materials 3 and 4 are reacted to prepare the corresponding compounds. The mass spectra of the prepared compounds are measured and their mass-to-charge ratios m / z are recorded. Details are shown in Table 2 below:

[0163] Table 2

[0164]

[0165] Preparation Example 4

[0166] This preparation example provides the intermediate MH1 and its synthesis method, the synthesis method is as follows:

[0167]

[0168] To a three-necked flask, dichloromethane (100 mL) and carbazole (3.3 g) were added, the temperature was lowered to 0-5°C, and anhydrous aluminum chloride (8.0 g) was added in batches. After the addition, the mixture was stirred at 0-5°C for 20 minutes. Then, 20 mL of a dichloromethane solution containing 2 g of 1-methylcyclohexene was slowly added dropwise at 5-10°C. After the addition, the mixture was kept at 5-10°C for 30 minutes, then heated to 25-30°C and kept for 1 hour. The reaction solution was slowly poured into ice water, separated, and the organic layer was washed until neutral. The mixture was separated by silica gel column chromatography with petroleum ether: ethyl acetate = 20:1 (volume ratio) to give intermediate MH1 (2.1 g).

[0169] The mass spectrum of the intermediate MH1 was measured, m / z: 263.17.

[0170] The nuclear magnetic resonance of the intermediate MH1 was measured, and the data were as follows: 1H-NMR (Bruker, Switzerland, AvanceⅡ400MHz nuclear magnetic resonance spectrometer, CDCl3), δ8.32 (d, 1H), δ8.11 (m, 1H), 7.59 (m, 1H), δ7.53 (d, 1H), δ7.35 (m, 1H), δ7.30 (s, 1H), δ7.21~7.16 (m, 2H), δ1.71~1.54 (m, 5H), δ1.42~1.30 (m, 7H), δ1.04 (m, 1H).

[0171] It should be noted that the methyl peak is a single peak, ranging from δ1.42 to 1.30 (m, 7H), at δ1.35.

[0172] Preparation Example 5

[0173] This preparation example provides the intermediate MH1 and its synthesis method, the synthesis method is as follows:

[0174]

[0175] To a three-necked flask, dichloromethane (100 mL) and carbazole (1.6 g) were added, the temperature was lowered to 0-5°C, and anhydrous aluminum chloride (8.0 g) was added in batches. After the addition was completed, the mixture was stirred at 0-5°C for 20 minutes. Then, 20 mL of a dichloromethane solution containing 2 g of 1-methylcyclohexene was slowly added dropwise at 5-10°C. After the addition was completed, the mixture was kept at 5-10°C for 30 minutes, then heated to 25-30°C and kept for 1 hour. The reaction solution was slowly poured into ice water, separated, and the organic layer was washed until neutral. The mixture was separated by silica gel column chromatography with petroleum ether: ethyl acetate = 20:1 (volume ratio) to give intermediate MH2 (1.3 g).

[0176] The mass spectrum of the intermediate MH3 was measured, m / z: 359.26.

[0177] Preparation Examples 6-8

[0178] Preparation Examples 6-8 provide an intermediate and a synthesis method thereof, respectively. The synthesis method of the intermediate refers to the preparation method of intermediate MH1. The corresponding intermediate is prepared by reacting raw material 4 and raw material 5. The mass spectrum of the prepared intermediate is measured and the m / z is recorded. Details are shown in Table 3 below:

[0179] Table 3

[0180]

[0181] Synthesis Example 6 Synthesis of Compound E1

[0182] This synthesis example provides compound E1 and its synthesis method, the synthesis method is as follows:

[0183]

[0184] Under a nitrogen atmosphere, 110 mL of dry toluene, 5.3 g of intermediate E1-1, 2.8 g of intermediate MH1, Pd(dba)2 (bis(dibenzylideneacetonepalladium, 0.1 g), 0.8 g of a 10% mass percentage tri-tert-butylphosphine toluene solution (the mass of tri-tert-butylphosphine is 0.08 g) and 1.2 g of sodium tert-butoxide were added to a three-necked flask, heated to reflux temperature, reacted for 6 h, cooled to room temperature, and separated by adding water. The organic layer was then washed with water until neutral, dried over magnesium sulfate, filtered to remove the magnesium sulfate, concentrated to dryness, and crystallized from a mixed solvent of chloroform and toluene to obtain compound E1 (5.6 g).

[0185] Compound E1 was detected by mass spectrometry: the mass-to-charge ratio (m / z) was measured to be 752.33.

[0186] Synthesis Examples 7-14

[0187] Synthesis Examples 7-14 provide a compound and a synthesis method thereof, respectively. The synthesis method of the compound refers to the preparation method of Compound E1, combined with common knowledge in the art, and the corresponding compound is prepared by reacting Raw Materials 7 and 8. The mass spectra of the prepared compounds are measured and the m / z is recorded. Details are shown in Table 4 below:

[0188] Table 4

[0189]

[0190]

[0191] Among them, the synthesis of intermediate E7-1 is as follows:

[0192]

[0193] Under nitrogen protection, 100 mL of dioxane was added to a three-necked flask, followed by intermediate E7-3 (4.8 g), intermediate E7-2 (3.0 g), K3PO4 (6.1 g) and tetrakistriphenylphosphine palladium (0.3 g). The temperature was slowly raised to reflux and the reaction was carried out for 12 h. Toluene and water were added to separate the organic layer. The organic layer was washed with water and dried over magnesium sulfate. After the magnesium sulfate was removed by filtration, the solvent was removed under reduced pressure. The product was separated by silica gel column chromatography and eluted with petroleum ether: ethyl acetate: dichloromethane = 20:1:3 (volume ratio) to obtain intermediate E7-1 (4.3 g).

[0194] The intermediate E7-1 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 621.24.

[0195] The synthesis of other compounds not listed can be carried out by referring to the above examples in combination with common knowledge in the art.

[0196] The specific structures of some of the compounds used in the following application examples and comparative application examples are as follows:

[0197]

[0198]

[0199] The synthesis of compound DE1 is as follows:

[0200]

[0201] Compound DE1 was prepared by referring to the synthetic method of compound E1.

[0202] The mass spectrum of compound DE1 was measured, m / z: 801.33.

[0203] The synthesis of compound DE3 is as follows:

[0204]

[0205] Compound DE3 was prepared by referring to the synthetic method of compound E1.

[0206] The mass spectrum of compound DE3 was measured, m / z: 827.34.

[0207] The synthesis of compound DE5 is as follows:

[0208]

[0209] Compound DE5 was prepared by referring to the synthetic method of compound E1.

[0210] The mass spectrum of compound DE5 was measured, m / z: 738.32.

[0211] Application Example 1

[0212] This application example provides a blue organic electroluminescent device, using the compound E1 provided by the present invention as the main material of the light-emitting layer. The structure of the blue organic electroluminescent device is:

[0213] ITO / HT-1: HI-2[5%](80nm) / HT-1(30nm) / EB-2(20nm) / host material: PBD-1[5%](35nm) / ETL-1(25nm) / LiF(0.5nm) / Al(150nm).

[0214] The preparation method of the blue organic electroluminescent device is as follows:

[0215] The material was placed in a vacuum chamber and evacuated to 1×10 -5 ~1×10-6 Pa, vacuum evaporating the above materials onto the cleaned ITO substrate in sequence to prepare an OLED device.

[0216] Among them, PBD-1[5%] refers to the doping ratio of the dye, that is, the volume ratio of the main material to the dye PBD-1 is 95:5; HT-1:HI-2[5%] refers to the ratio of the P-type dopant, that is, the volume ratio of the hole material HT-1 and the P-type dopant HI-2 is 95:5, and HT-1 is the hole transport material; HT-1:HI-2[5%] is used as the hole injection layer material, and EB-2 is the electron blocking layer material.

[0217] Application Example 2-6

[0218] Application Examples 2-6 each provide a blue organic electroluminescent device, which differs from Application Example 1 only in that the main material compound E1 of the light-emitting layer is replaced with other compounds (see Table 5 below for details). Other preparation steps and conditions are the same as those of Application Example 1.

[0219] Comparative Application Examples 1-2

[0220] Comparative Application Examples 1 and 2 each provide an organic electroluminescent device, which differs from Application Example 1 only in that the host material compound E1 of the light-emitting layer is replaced with other compounds (see Table 5 below for details). Other preparation steps and conditions are the same as those of Application Example 1.

[0221] Performance Testing

[0222] The brightness, driving voltage, current efficiency and LT95 of the organic electroluminescent device provided above were tested, wherein the current efficiency is the brightness of 1000cd / m 2 The corresponding value, LT95, refers to maintaining the initial current density of the device at 10mA / cm 2 The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density is constant, where the driving voltage, current efficiency and LT95 are relative values. The specific test results are shown in Table 5 below:

[0223] Table 5

[0224] Main material <![CDATA[Luminance / (cd / m 2 )]]> Driving voltage Current efficiency LT95 Application Example 1 E1 1000 0.94 1.11 1.06 Application Example 2 E2 1000 0.92 1.07 1,15 Application Example 3 E3 1000 0.99 1.06 1.09 Application Example 4 E4 1000 0.96 1.02 1.36 Application Example 5 E5 1000 0.95 1.18 1.03 Application Example 6 E11 1000 0.76 1.03 1.02 Comparative Application Example 1 DE4 1000 1 1 1 Comparative Application Example 2 DE5 1000 1.02 0.93 1.03

[0225] As can be seen from the above, the present invention has prepared carbazole compounds with excellent performance by designing the structure of the carbazole compounds. The organic electroluminescent devices prepared using the carbazole compounds as the material of the light-emitting layer have high current efficiency, long life and low driving voltage.

[0226] Application Examples 7-10, Comparative Application Examples 3-5

[0227] Application Examples 7-10 and Comparative Application Examples 3-5 respectively provide a blue light organic electroluminescent device. The only difference from Application Example 1 is that the main material compound E1 of the light-emitting layer is replaced by other compounds (see Table 6 below for details). The other preparation steps and conditions are the same as those of Application Example 1.

[0228] Performance Testing

[0229] The brightness, driving voltage, current efficiency and LT95 of the organic electroluminescent device provided above were tested, wherein the current efficiency is the brightness of 1000cd / m 2 The corresponding value, LT95, refers to maintaining the initial current density of the device at 10mA / cm 2 The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density is constant, where the driving voltage, current efficiency and LT95 are relative values. The specific test results are shown in Table 6 below:

[0230] Table 6

[0231] Main material <![CDATA[Brightness / (cd / m 2 )]]> Driving voltage Current efficiency LT95 Application Example 7 E6 1000 1.02 1.56 1.08 Application Example 8 E8 1000 0.98 1.22 1.47 Application Example 9 E9 1000 0.95 1.29 1.39 Application Example 10 E10 1000 0.82 1.09 1.12 Comparative Application Example 3 DE1 1000 1 1 1 Comparative Application Example 4 DE2 1000 1.05 0.93 1.06 Comparative Application Example 5 DE3 1000 1.02 0.96 1.07

[0232] As can be seen from the above, the present invention has prepared carbazole compounds with excellent performance by designing the structure of the carbazole compounds. The organic electroluminescent devices prepared using the carbazole compounds as the material of the light-emitting layer have high current efficiency, long life and low driving voltage.

[0233] Application Example 11, Comparative Application Example 6

[0234] Application Example 11 and Comparative Application Example 6 each provide a blue organic electroluminescent device. The only difference from Application Example 1 is that the main material compound E1 of the light-emitting layer is replaced by other compounds (see Table 7 below for details). The other preparation steps and conditions are the same as those of Application Example 1.

[0235] Performance Testing

[0236] The brightness, driving voltage, current efficiency and LT95 of the organic electroluminescent device provided above were tested, wherein the current efficiency is the brightness of 1000cd / m 2 The corresponding value, LT95, refers to maintaining the initial current density of the device at 10mA / cm 2 The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density is constant, where the driving voltage, current efficiency and LT95 are relative values. The specific test results are shown in Table 6 below:

[0237] Table 7

[0238] Main material <![CDATA[Brightness / (cd / m 2 )]]> Driving voltage Current efficiency LT95 Application Example 11 E7 1000 0.98 1.11 1.30 Comparative Application Example 6 DE6 1000 1 1 1

[0239] As can be seen from the above, the present invention has prepared carbazole compounds with excellent performance by designing the structure of the carbazole compounds. The organic electroluminescent devices prepared using the carbazole compounds as the material of the light-emitting layer have high current efficiency, long life and low driving voltage.

[0240] Application Example 12, Comparative Application Examples 7-8

[0241] Application Example 12 and Comparative Application Examples 7-8 respectively provide a blue organic electroluminescent device. The only difference from Application Example 1 is that the main materials of the light-emitting layer are two compounds, including a first component and a second component, and the volume ratio of the two is 1:1 (see Table 6 below for details). The other preparation steps and conditions are the same as those of Application Example 1.

[0242] Performance Testing

[0243] The brightness, driving voltage, current efficiency and LT95 of the organic electroluminescent device provided above were tested, wherein the current efficiency is the brightness of 1000cd / m 2 The corresponding value, LT95, refers to maintaining the initial current density of the device at 10mA / cm 2 The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density is constant, where the driving voltage, current efficiency and LT95 are relative values. The specific test results are shown in Table 8 below:

[0244] Table 8

[0245]

[0246] From the above, it can be seen that the organic electroluminescent device prepared by the present invention by selecting the composition composed of the carbazole compound and the compound of formula II as the light-emitting layer material has high current efficiency, long life and low driving voltage.

[0247] In summary, the present invention designs the structure of carbazole compounds to prepare carbazole compounds with excellent performance. The organic electroluminescent device prepared by using the carbazole compounds as the material of the light-emitting layer has high current efficiency, long life and low driving voltage.

[0248] The applicant declares that the present invention uses the above-described embodiments to illustrate the detailed process flow of the present invention, but the present invention is not limited to the above-described detailed process flow, that is, it does not mean that the present invention must rely on the above-described detailed process flow to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacements for various raw materials in the products of the present invention, addition of auxiliary ingredients, and selection of specific methods, etc., are all within the scope of protection and disclosure of the present invention.

Claims

1. A carbazole compound, characterized in that The carbazole compound has a structure shown in the following formula I: wherein Ar1, Ar2, and Ar3 are each independently selected from at least one of a C6-C20 aryl group or a C6-C20 heteroaryl group; Ar is selected from at least one of a C6-C20 aryl group or a C6-C20 heteroaryl group; At least one hydrogen atom in the compound of formula I is substituted by a group having the structure represented by formula I-1, ring A represents a C3-C12 cycloalkyl group, and R is selected from a C1-C12 alkyl group; The remaining hydrogen atoms in the compounds of formula I may each independently be replaced by a deuterium atom.

2. The carbazole compound according to claim 1, wherein The C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, butyl, pentyl, methylcyclopentyl, hexyl, methylcyclohexyl, heptyl, octyl, adamantyl, bicyclo[2.2.1]heptyl or bicyclo[2.2.2]octyl; Preferably, the C3-C12 cycloalkyl group is selected from any one of cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclononyl groups; Preferably, the C6-C20 aryl group is selected from any one of phenyl, naphthyl, biphenyl or 9,9-dimethylfluorenyl; Preferably, the C6-C20 heteroaryl group is selected from any one of a carbazolyl group, a dibenzofuranyl group or a dibenzothiophenyl group.

3. The carbazole compound according to claim 1 or 2, characterized in that Ar1, Ar2, and Ar3 are each independently selected from at least one of phenyl, naphthyl, biphenyl, dibenzofuranyl, and dibenzothiophenyl; Preferably, any two of Ar1, Ar2, and Ar3 are selected from phenyl groups, and the other is selected from at least one of phenyl, naphthyl, biphenyl, dibenzofuranyl, and dibenzothiophenyl groups; Preferably, Ar is selected from any one of phenyl, naphthyl, biphenyl, 9,9-dimethylfluorenyl, dibenzofuranyl, phenyl-substituted dibenzofuranyl, dibenzothiophenyl, phenyl-substituted dibenzothiophenyl, carbazolyl, and phenyl-substituted carbazolyl; Preferably, the ring A represents any one of cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclononyl; Preferably, R is selected from any one of methyl, ethyl, n-propane, isopropane, n-butyl, isobutyl, tert-butyl, cyclopentyl and cyclohexyl.

4. The carbazole compound according to any one of claims 1 to 3, characterized in that The carbazole compound has a structure shown in the following formula I-1 or formula I-2: Wherein, Ar1, Ar2, Ar3, Ar have the same definitions as in claim 1; At least one H atom in the compound of formula I-1 or formula I-2 is substituted by a group having formula I-1; The remaining hydrogen atoms in the compound of formula I-1 and the compound of formula I-2 can each independently be replaced by a deuterium atom; Preferably, the carbazole compound has a structure as shown in the following formula I-11 or formula I-2: Wherein, Ar1, Ar2, Ar3, Ar have the same definitions as in claim 1; In the compound of formula I-1 and the compound of formula I-2, y is each independently selected from 0 or 1; The hydrogen atoms in the compound of formula I-1 and the compound of formula I-2 may each independently be replaced by a deuterium atom.

5. The carbazole compound according to any one of claims 1 to 4, characterized in that The carbazole compound is selected from any one of the following substituted or unsubstituted compounds: The substitution means that the hydrogen atoms in the carbazole compound can be independently replaced by deuterium atoms.

6. An intermediate, characterized in that The intermediates include the following compounds: The intermediate is used to prepare the carbazole compound according to any one of claims 1 to 5.

7. A composition, characterized in that The composition comprises at least a first component and a second component, wherein the first component comprises at least one carbazole compound according to the first aspect, and the second component comprises at least one compound having a structure shown in the following formula II: wherein R1, R2, R3, and R4 are each independently selected from a C6-C20 aryl group or a C6-C20 heteroaryl group; m, o, and p are each independently selected from an integer between 0 and 4; n is selected from an integer between 0 and 3; The hydrogen atoms in the compound of formula II may each independently be substituted by at least one of a deuterium atom, -F, -CN, a C1-C12 alkyl group, a C1-C12 alkoxy group, a triphenylsilyl group, a triphenylmethyl group, a C6-C20 aryl group or a C6-C20 heteroaryl group.

8. The composition according to claim 7, characterized in that The C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, butyl, pentyl, methylcyclopentyl, hexyl, methylcyclohexyl, heptyl, octyl, adamantyl, bicyclo[2.2.1]heptyl or bicyclo[2.2.2]octyl; Preferably, the C1-C12 alkoxy group is selected from any one of methoxy, ethoxy, propoxy, butoxy, pentyloxy or hexyloxy; Preferably, the C6-C20 aryl group is selected from any one of phenyl, naphthyl, biphenyl or 9,9-dimethylfluorenyl; Preferably, the C6-C20 heteroaryl group is selected from any one of carbazolyl, dibenzofuranyl or dibenzothiophenyl; Preferably, m+n+o+p=0; Preferably, m+n=0, o+p=1; Preferably, m+n=0, o=0, p=1; Preferably, m+n=0, o=1, p=0; Preferably, m+n=0, o=0, p=2; Preferably, m+n=0, o=2, p=0; Preferably, m+n=0, o=1, p=1; Preferably, m=1, n=1, o=0, p=1; Preferably, m=1, n=o=0, and p=1.

9. The composition according to claim 7 or 8, characterized in that R1, R2, R3, and R4 are each independently selected from any one of phenyl, naphthyl, biphenyl, 9,9-dimethylfluorenyl, dibenzofuranyl, dibenzothiophenyl, and carbazolyl; Preferably, R1, R2, and R3 are each independently selected from any one of phenyl, naphthyl, or biphenyl, more preferably phenyl; Preferably, R4 is selected from any one of phenyl, naphthyl, biphenyl, 9,9-dimethylfluorenyl, dibenzofuranyl, dibenzothiophenyl, and carbazolyl; Preferably, the hydrogen atoms in the compound of formula II can each independently be replaced by at least one of a deuterium atom (-D), -F, -CN, a methyl group, an ethyl group, a propyl group, a tert-butyl group, a methoxy group, an ethoxy group, a propoxy group, a phenyl group, a naphthyl group, a biphenyl group, a carbazolyl group or a triphenylsilyl group; Preferably, the compound of formula II is selected from any one of the following substituted or unsubstituted compounds: The substitution means that the hydrogen atoms in the carbazole compound can be independently replaced by deuterium atoms.

10. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises an anode, a cathode and an organic thin film layer arranged between the anode and the cathode; The material of the organic thin film layer comprises the carbazole compound according to any one of claims 1 to 5 or the composition according to any one of claims 7 to 9; Preferably, the organic thin film layer includes a light-emitting layer, and the main material of the light-emitting layer includes the carbazole compound according to any one of claims 1 to 5 or the composition according to any one of claims 7 to 9; Preferably, the light-emitting layer is a phosphorescent light-emitting layer; Preferably, the organic electroluminescent device is a blue organic electroluminescent device.

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