A carbazole compound, an intermediate and an organic electroluminescent device

Abstract

The application provides a carbazole compound, an intermediate and an organic electroluminescent device, and relates to the technical field of organic electroluminescent materials. The carbazole compound is obtained by designing the structure of a compound, and is suitable for an electron blocking layer material of an organic electroluminescent device. The prepared organic electroluminescent device has high current efficiency and long service life, and is suitable for industrial application.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescent materials technology, specifically relating to a carbazole compound, an intermediate, and an organic electroluminescent device. Background Technology

[0002] Compared to other flat panel displays, such as liquid crystal displays (LCDs), plasma display panels (PDPs), and field emission displays (FEDs), organic light-emitting devices (OLEDs) have a simpler structure, higher brightness, excellent viewing angle characteristics, faster response speed, and lower driving voltage. They are also easy to process. Therefore, they are widely used as light sources for flat panel displays (such as wall-mounted TVs) or as backlight units for displays, lighting fixtures, and advertising boards.

[0003] The structure of an organic light-emitting diode (OLED) specifically includes an anode, a cathode, and an organic layer between them. To improve the efficiency and stability of OLEDs, the organic layer comprises multiple functional layers made of different materials. To meet the increasingly demanding performance requirements of OLED devices, there is an urgent need to develop a wider variety of materials to improve the performance of OLED devices in terms of current efficiency, lifetime, and other aspects. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a carbazole compound, an intermediate, and an organic electroluminescent device. This compound is suitable as an electron blocking layer material for organic electroluminescent devices. The organic electroluminescent device prepared thereby has high current efficiency and long service life, making it suitable for industrial applications.

[0005] To achieve this objective, the present invention adopts the following technical solution:

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

[0007]

[0008] Formula I;

[0009] Ar1 to Ar3 are each independently selected from any one of phenyl, naphthyl, and biphenyl;

[0010] Ar4 and Ar5 are each independently selected from any one of H, phenyl, naphthyl, and biphenyl;

[0011] R is selected from any one of H and C1~C12 alkyl groups;

[0012] In the compound of formula I, each hydrogen atom can be independently replaced by a deuterium atom.

[0013] In this invention, "D" represents a deuterium atom, and the same applies below.

[0014] This invention designs the structure of compounds to obtain high-performance carbazole compounds. These compounds are suitable as electron blocking layer materials for organic electroluminescent devices. The organic electroluminescent devices prepared in this way have high current efficiency and long service life, and are suitable for industrial applications.

[0015] Preferably, two or more of Ar1, Ar2, and Ar3 are selected from phenyl.

[0016] Preferably, Ar1, Ar2, and Ar3 are all selected from phenyl groups.

[0017] Preferably, R, Ar4, and Ar5 are all selected from H.

[0018] Preferably, R is selected from any one of C1 to C12 alkyl groups, and at least one of Ar4 and Ar5 is selected from H.

[0019] Preferably, R is selected from any one of C1 to C12 alkyl groups, and Ar4 and Ar5 are both selected from phenyl groups.

[0020] Preferably, the C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, and tert-butyl.

[0021] Preferably, the carbazole compound is selected from any one of the following substituted or unsubstituted compounds:

[0022]

[0023]

[0024] ;

[0025] The substitution refers to the fact that each hydrogen atom in the above compound can be independently replaced by a deuterium atom.

[0026] Preferably, the carbazole compound is selected from any one of substituted or unsubstituted compounds 1 to 9:

[0027] , , , , , , , , ;

[0028] The substitution refers to the fact that each hydrogen atom in compounds 1 to 9 can be independently replaced by a deuterium atom.

[0029] In a second aspect, the present invention provides an intermediate selected from the following compounds 2-1:

[0030] ;

[0031] In the above compound 2-1, each hydrogen atom can be independently replaced by a deuterium atom;

[0032] The intermediate is used to prepare carbazole compounds as described in the first aspect.

[0033] Thirdly, the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising an anode, a cathode, and an organic thin film layer disposed between the anode and the cathode;

[0034] The organic thin film layer includes carbazole compounds as described in the first aspect.

[0035] Preferably, the organic thin film layer includes an electron blocking layer and a light-emitting layer, wherein the electron blocking layer includes the carbazole compound.

[0036] Preferably, the electron blocking layer is prepared by vapor deposition.

[0037] Preferably, the light-emitting layer comprises a host material and a dopant material, wherein the dopant material is also called a dye, which includes phosphorescent materials. The host material of the light-emitting layer can be a single compound or a mixture of two or more compounds.

[0038] Preferably, the light-emitting layer is a phosphorescent light-emitting layer, which includes a host material and a dopant material; preferably, the dopant material of the phosphorescent light-emitting layer includes a phosphorescent material. The phosphorescent material is also known as a triplet light-emitting material, referring to light emitted from a substance in a triplet excited state. In this invention, the specific selection of the phosphorescent material is not particularly limited; commonly used dopant materials for light-emitting layers in the art are applicable, and exemplary examples include, but are not limited to, compounds having the structure shown in formula PD.

[0039]

[0040] PD (Power Generation)

[0041] In the formula PD, M is selected from any one of Ir, Pt, Pd, Os, Ti, Zr, Hf, Eu, Tb, Tm, Cu, or Au;

[0042] Y1 to Y4 are each independently selected from carbon or nitrogen;

[0043] Y1 and Y2 can be connected by a single key or a double key, and Y3 and Y4 can be connected by a single key or a double key.

[0044] Cy1 and Cy2 are each independently selected from any one of phenyl, naphthyl, fluorenyl, spirofluorenyl, indyl, pyrroleyl, thiopheneyl, furanyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, quinolinyl, isoquinolinyl, benzoquinolinyl, quinoxalinyl, quinazolinyl, carbazoleyl, benzimidazolyl, benzofuranyl, benzothiopheneyl, isobenzothiopheneyl, benzimidazolyl, benzozolyl, triazolyl, tetrazolyl, diazolyl, triazinyl, dibenzofuranyl, dibenzothiopheneyl, N-hexacarbazolyl, N-hexadibenzofuranyl, wherein Cy1 and Cy2 may optionally be linked to each other via a single bond or an organic linking group;

[0045] Any two or more ligands of M can be connected by single or double bonds, or by O or S bridging, or by any chemical group or chemical structure to form a structure that conforms to chemical principles.

[0046] R 91 and R 92Each group is independently selected from -H, -D, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidine, hydrazine, hydrazone, carboxylic acid group, carboxylate group, sulfonic acid group, sulfonate group, phosphate group, phosphate group, -SF5, substituted or unsubstituted C1~C60 (e.g., C1, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55, or C60) alkyl, substituted or unsubstituted C2~C6 0 (e.g., can be C2, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55, or C60) alkenyl, substituted or unsubstituted C2~C60 (e.g., can be C2, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55, or C60, etc.) alkynyl, substituted or unsubstituted C1~C60 (e.g., can be C1, C5, C10, C15, C20, ... C25, C30, C35, C40, C45, C50, C55, or C60) alkoxy, substituted or unsubstituted C2~C10 (e.g., can be C2, C3, C4, C5, C6, C7, C8, C9, or C10) heterocyclic alkyl, substituted or unsubstituted C6~C60 (e.g., can be 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 the following: C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54, or C60) aryloxy group, substituted or unsubstituted C6~C60 (e.g., it can be C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54, or C60) arylthio group, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, or substituted or unsubstituted monovalent non-aromatic fused heterocyclic group; R 91 and R 92 In this context, the substituent is preferably at least one of -D, -F, C1~C6 alkyl, and C6~C12 aryl.

[0047] a1 and a2 are each independent integers selected from 1 to 5, for example, they can be 1, 2, 3, 4 or 5;

[0048] b is an integer from 0 to 4, for example, it can be 0, 1, 2, 3 or 4;

[0049] a is selected from 1, 2, or 3;

[0050] L1 can be a monovalent organic ligand, a divalent organic ligand, or a trivalent organic ligand.

[0051] Preferably, the PD compound is selected from any one of the following compounds:

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064] .

[0065] Preferably, 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%), more preferably 70% to 99.5%, and even more preferably 85% to 95%.

[0066] Preferably, the phosphorescent luminescent layer includes a green phosphorescent luminescent layer, a red phosphorescent luminescent layer, a yellow phosphorescent luminescent layer, and a blue phosphorescent luminescent layer.

[0067] Preferably, the organic electroluminescent device is a blue organic electroluminescent device.

[0068] Preferably, the phosphorescent luminescent layer is a blue phosphorescent luminescent layer.

[0069] Preferably, the organic thin film layer further includes one or a combination of hole injection layer and hole transport layer.

[0070] In this invention, the hole layer material (including the hole injection layer, the hole transport layer, and the electron blocking layer) may further include a compound having the structure shown in the formula HT-GH4:

[0071]

[0072] Among them, L 41 Selected from single-bonded, C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40) aryl, and C6-C20 (e.g., C6, C8, C10, C12, C16, or C20) heteroaryl;

[0073] Ar 41 Ar 42 Each is independently selected from C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40) aryl groups and C6-C20 (e.g., C6, C8, C10, C12, C16, or C20) heteroaryl groups;

[0074] X is selected from CR 41 R 42 Or NR 43 , where R 41 R 42 R 43 Each is independently selected from substituted or unsubstituted phenyl groups (the substituents are selected from C1-C6 (e.g., C1, C2, C3, C4, C5, or C6) alkyl, C1-C6 (e.g., C1, C2, C3, C4, C5, or C6) alkoxy, dibenzofuranyl, naphthyl, triphenylene, fluoranyl, 9,9-dimethylfluorenyl, biphenyl, substituted or unsubstituted dibenzofuranyl (the substituent is phenyl), substituted or unsubstituted dibenzothiophenyl (the substituent is phenyl), dibenzofuran-substituted thiophenyl, C1-C6 (e.g., C1, C2, C3, C4, C5, or C6) alkyl groups, R 41 R 42 They can be connected into a ring using a single key.

[0075] Preferably, the compound of formula HT-GH4 is selected from any one of the following compounds:

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095] .

[0096] Preferably, the organic thin film layer further includes one or a combination of several of the following: an electron injection layer, an electron transport layer, and a hole blocking layer.

[0097] Hole blocking layers (HBLs) can confine holes and / or excitons within the emissive layer to improve device current efficiency and lifetime. Compared to emissive layer materials closest to the HBL interface, HBL materials exhibit lower HOMO (larger absolute values) and / or higher triplet energies.

[0098] An electron transport layer (ETL) may comprise a material capable of transporting electrons. The ETL may be intrinsic (undoped) or doped, and doping can be used to enhance conductivity. In this invention, there are no particular limitations on the ETL material; any metal complex or organic compound can be used, as long as it can transport electrons. Generally, electron transport layer materials contain at least one of the following structural segments: pyridine, pyrimidine, triazine, benzimidazole, benzoxazole, benzothiazole, N-naphthalene, N-phenanthroline, N-carbazole, N-dibenzofuran, and N-dibenzothiophene.

[0099] In this invention, no special restrictions are placed on the electron transport layer material, and exemplary structures include, but are not limited to, the following:

[0100]

[0101]

[0102] .

[0103] In this invention, no special restrictions are placed on the electron injection material. For example, fluorides of alkali metals or alkaline earth metals, as well as corresponding oxides or carbonates (e.g., LiF, Li2O, BaF2, MgO, NaF, CsF, Cs2CO3) or lithium quinoline (LiQ) can be used.

[0104] In this invention, the cathode material is a metal with 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), a metal alloy composed of multiple metals (an alloy composed of alkali metals or alkaline earth metals and silver, such as 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 function can also be used, such as Ag or Al. In this case, combinations of the metals are typically used, such as Ca / Ag, Mg / Ag, or Ba / Ag.

[0105] Fourthly, the present invention provides a display device comprising the organic electroluminescent device as described in the third aspect.

[0106] Compared with the prior art, the present invention has the following beneficial effects:

[0107] This invention designs the structure of compounds to obtain carbazole compounds, which are suitable as electron blocking layer materials for organic electroluminescent devices. The organic electroluminescent devices prepared in this way have high current efficiency and long service life, and are suitable for industrial applications. Detailed Implementation

[0108] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0109] Preparation Example 1: Synthesis of Intermediate 2-1

[0110]

[0111] Add 0.01 mol of intermediate 2-0 and 80 mL of DMF to a three-necked flask, add 0.01 mol of NBS (N-bromosuccinimide) at 20-25 °C, and react at 20-25 °C for 6 hours. Pour into water, filter, and crystallize the obtained solid with chlorobenzene to obtain intermediate 2-1.

[0112] Intermediate 2-1 was analyzed by mass spectrometry, m / z: 635.16.

[0113] Synthesis Example 1: Synthesis of Compound 1

[0114]

[0115] Under nitrogen protection, 70 mL of toluene, 30 mL of ethanol, and 10 mL of water were added sequentially to a three-necked flask. Then, 5.8 g of intermediate 1-1, 1.3 g of phenylboronic acid, 2.12 g of sodium carbonate, and 0.23 g of tetrakis(triphenylphosphine)palladium were added. The mixture was slowly heated to reflux and reacted for 8 h. After cooling to room temperature, water was added to separate the contents. The organic layer was washed with water and dried with magnesium sulfate. After removing the desiccant, the mixture was concentrated to dryness and crystallized with ethanol to obtain 3.9 g of compound 1.

[0116] The obtained compound 1 was subjected to mass spectrometry, and the mass-to-charge ratio (m / z) was measured to be 577.22.

[0117] Synthesis Examples 2-6

[0118] Synthesis Examples 2-6 synthesized one compound each (see Table 1 below for details). The synthesis method of the compound was the same as that of compound 1 provided in Synthesis Example 1, except that the raw materials were different. The obtained compounds were analyzed by mass spectrometry, and their mass-to-charge ratio data are shown in Table 1 below.

[0119] Table 1

[0120]

[0121]

[0122] Compounds not listed above can be synthesized by referring to the above methods and combining them with common knowledge in the field.

[0123] The specific structures of some of the compounds used in the following application examples and comparative application examples are as follows:

[0124] , , , , , , , , , , , , , , , , , , .

[0125] Application Example 1

[0126] This application example provides a blue organic electroluminescent device, using compound 2 provided by the present invention as an electron blocking layer material. The structure of the blue organic electroluminescent device is as follows:

[0127] ITO / HT-1:HI-2[5%](80nm) / HT-1(30nm) / Compound 2(20nm) / H1:PBD-1[5%](35nm) / ETL-1(25nm) / LiF(0.5nm) / Al(150nm).

[0128] The fabrication method of the blue organic electroluminescent device is as follows:

[0129] The material was placed inside a vacuum chamber, and the vacuum was evacuated to 1×10⁻⁶. -5 ~1×10 -6 Pa, the above materials are sequentially vacuum-deposited onto the cleaned ITO substrate to prepare OLED devices.

[0130] Wherein, H1:PBD-1[5%] (35nm) is the light-emitting layer, H1:PBD-1[5%] refers to the doping ratio of the dye in the light-emitting layer, that is, the volume ratio of the main material H1 to the dye PBD-1 in the light-emitting layer is 95:5, and the film thickness of the light-emitting layer is 35nm.

[0131] HT-1:HI-2[5%] (80nm) is the hole injection layer. HT-1:HI-2[5%] refers to the proportion of P-type dopant in the hole injection layer. That is, the volume ratio of hole material HT-1 and P-type dopant HI-2 in the hole injection layer is 95:5, and the thickness of the hole injection layer is 80nm.

[0132] HT-1 (30nm) is a hole transport layer with a film thickness of 30nm;

[0133] Compound 2 (20 nm) is an electron blocking layer, which is composed of compound 2 and has a film thickness of 20 nm.

[0134] ETL-1 (25nm) is an electron transport layer with a film thickness of 25nm.

[0135] The LiF (0.5nm) layer is the electron injection layer, and the film thickness is 0.5nm.

[0136] ITO refers to the anode, and Al (150nm) refers to the cathode.

[0137] Application Examples 2-3

[0138] Application Examples 2-3 provide blue organic electroluminescent devices. The only difference from Application Example 1 is that the electron blocking layer material is replaced by other compounds instead of compound 2 (see Table 2 below). The other preparation steps and conditions are the same as in Application Example 1.

[0139] Compare and contrast examples 1 and 2

[0140] Comparative Application Examples 1 and 2 provide a blue organic electroluminescent device. The only difference from Application Example 1 is that the electron blocking layer material is replaced by other compounds instead of compound 2 (see Table 2 below). The other preparation steps and conditions are the same as in Application Example 1.

[0141] The luminance, current efficiency, and LT95 test results of the organic electroluminescent devices provided in the above application examples or comparative application examples are shown in Table 2. The current efficiency is calculated when the luminance is 1000 cd / m². 2 The corresponding value, LT95, refers to maintaining an initial device current density of 10 mA / cm². 2 The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density remains unchanged. Here, current efficiency and LT95 are relative values, with the current efficiency and LT95 measured in Application Example 1 as the reference, respectively.

[0142] The specific test results are shown in Table 2 below:

[0143] Table 2

[0144]

[0145] As can be seen from Table 2 above, the present invention obtains carbazole compounds by designing the structure of the compounds. These compounds are suitable as electron blocking layer materials for organic electroluminescent devices, and the organic electroluminescent devices prepared by the invention have high current efficiency and long service life.

[0146] Application Example 4

[0147] Application Example 4 provides a blue organic electroluminescent device. The only difference from Application Example 1 is that the electron blocking layer material is replaced by other compounds instead of compound 2 (see Table 3 below). The other preparation steps and conditions are the same as in Application Example 1.

[0148] Compare and contrast examples 3-4

[0149] Comparative Application Examples 3-4 provide a blue organic electroluminescent device. The only difference from Application Example 1 is that the electron blocking layer material is replaced by other compounds instead of compound 2 (see Table 3 below). The other preparation steps and conditions are the same as in Application Example 1.

[0150] The luminance, current efficiency, and LT95 test results of the organic electroluminescent devices provided in the above application examples or comparative application examples are shown in Table 3. The current efficiency is calculated when the luminance is 1000 cd / m². 2 The corresponding value, LT95, refers to maintaining an initial device current density of 10 mA / cm². 2 The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density remains unchanged. Here, current efficiency and LT95 are relative values, with the current efficiency and LT95 measured in Application Example 4 as the reference, respectively.

[0151] The specific test results are shown in Table 3 below:

[0152] Table 3

[0153]

[0154] As can be seen from Table 3 above, the present invention obtains carbazole compounds by designing the structure of the compounds. These compounds are suitable as electron blocking layer materials for organic electroluminescent devices, and the organic electroluminescent devices prepared by the invention have high current efficiency and long service life.

[0155] Application Examples 5-7

[0156] Application Examples 5-7 provide blue organic electroluminescent devices. The only difference from Application Example 1 is that the electron blocking layer material is replaced by other compounds instead of compound 2 (see Table 4 below). The other preparation steps and conditions are the same as in Application Example 1.

[0157] The luminance, voltage, current efficiency, and LT95 test results of the above application examples or provided organic electroluminescent devices are shown in Table 4. The voltage and current efficiency are calculated based on a luminance of 1000 cd / m². 2 The corresponding value, LT95, refers to maintaining an initial device current density of 10 mA / cm². 2The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density remains unchanged. Here, voltage, current efficiency, and LT95 are all relative values, with the current efficiency and LT95 measured in Application Example 5 as the references, respectively.

[0158] The specific test results are shown in Table 4 below:

[0159] Table 4

[0160]

[0161] Application Examples 8-9

[0162] Application Examples 8-9 provide blue organic electroluminescent devices. The only difference from Application Example 1 is that the electron blocking layer material is replaced by other compounds instead of compound 2 (see Table 5 below). The other preparation steps and conditions are the same as in Application Example 1.

[0163] The luminance, voltage, current efficiency, and LT95 test results of the above application examples or provided organic electroluminescent devices are shown in Table 5. The voltage and current efficiency are calculated based on a luminance of 1000 cd / m². 2 The corresponding value, LT95, refers to maintaining an initial device current density of 10 mA / cm². 2 The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density remains unchanged. Here, voltage, current efficiency, and LT95 are all relative values, with the current efficiency and LT95 measured in Application Example 8 as the references, respectively.

[0164] The specific test results are shown in Table 5 below:

[0165] Table 5

[0166]

[0167] The present invention has been illustrated with the above embodiments to describe the detailed process flow of the present invention. However, the present invention is not limited to the above detailed process flow, that is, it does not mean that the present invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A carbazole compound, characterized in that, The carbazole compounds have the structure shown in Formula I: Formula I; Ar1 to Ar3 are each independently selected from any one of phenyl, naphthyl, and biphenyl; Ar4 and Ar5 are each independently selected from any one of H, phenyl, naphthyl, and biphenyl; R is selected from any one of H and C1~C12 alkyl groups; In the compound of formula I, each hydrogen atom can be independently replaced by a deuterium atom.

2. The carbazole compound according to claim 1, characterized in that, Two or more of Ar1, Ar2, and Ar3 are selected from phenyl; Preferably, Ar1, Ar2, and Ar3 are all selected from phenyl groups.

3. The carbazole compound according to claim 1, characterized in that, R, Ar4, and Ar5 are all selected from H; Preferably, R is selected from any one of C1 to C12 alkyl groups, and at least one of Ar4 and Ar5 is selected from H; Preferably, R is selected from any one of C1 to C12 alkyl groups, and Ar4 and Ar5 are both selected from phenyl groups.

4. The carbazole compound according to claim 1, characterized in that, The C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, and tert-butyl.

5. The carbazole compound according to claim 1, characterized in that, The carbazole compound is selected from any one of the following compounds, whether substituted or unsubstituted: ； The substitution refers to the fact that each hydrogen atom in the above compound can be independently replaced by a deuterium atom.

6. The carbazole compound according to claim 1, characterized in that, The carbazole compound is selected from any one of substituted or unsubstituted compounds 1 to 9: 、 、 、 、 、 、 、 、 ； The substitution refers to the fact that each hydrogen atom in compounds 1 to 9 can be independently replaced by a deuterium atom.

7. An intermediate, characterized in that, The intermediate is selected from the following compound 2-1: ； In the above compound 2-1, each hydrogen atom can be independently replaced by a deuterium atom; The intermediate is used to prepare carbazole compounds as described in any one of claims 1 to 6.

8. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes an anode, a cathode, and an organic thin film layer disposed between the anode and the cathode; The organic thin film layer includes a carbazole compound as described in any one of claims 1 to 6.

9. The organic electroluminescent device according to claim 8, characterized in that, The organic thin film layer includes an electron blocking layer and a light-emitting layer, wherein the electron blocking layer includes the carbazole compound.

10. The organic electroluminescent device according to claim 9, characterized in that, The light-emitting layer is a phosphorescent light-emitting layer, which includes a main material and a doping material. Preferably, the phosphorescent luminescent layer is a blue phosphorescent luminescent layer.

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