Carbazole compound and organic electroluminescent device containing same

Abstract

The invention provides a carbazole compound and an organic electroluminescent device containing the same. The carbazole compound has a structure as shown in a formula I or a formula II. The structure of the carbazole compound is designed, so that the carbazole compound is suitable for being used as a main body material of a light-emitting layer of the organic light-emitting device, and the organic light-emitting device has relatively high current efficiency and relatively long service life.

Description

Technical Field

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

[0002] Electroluminescence, also known as electric field luminescence, or EL for short, is a luminescence phenomenon in which a solid directly converts electrical energy into light energy under the action of an electric field generated by a voltage applied to two electrodes. Among them, the electroluminescence of organic materials belongs to injection-type composite luminescence. Organic electroluminescent materials can be divided into hole injection layer (HIL), hole transport layer (HTL), light-emitting layer (EML), electron transport layer (ETL), electron injection layer (EIL) and other materials according to their functions and device structures in organic electroluminescent (OLED) devices.

[0003] Currently, organic electroluminescence (OLED) has become the mainstream display technology, and accordingly, various new OLED materials have also been developed. However, its various performances need to be improved, especially in terms of efficiency, life, voltage, etc. In order to meet people's higher requirements for OLED devices, the field urgently needs to develop more types of blue light host materials with higher performance. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention aims to provide a carbazole compound and an organic electroluminescent device containing the same. In the present invention, the structure of the carbazole compound is designed to make it suitable as a main material of the light-emitting layer of the organic electroluminescent device, so that the organic electroluminescent device has higher current efficiency and longer life.

[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 or formula II:

[0007]

[0008] Wherein, in the compound of formula I or formula II, Ar2 is independently selected from C6-C40 aryl or C6-C30 heteroaryl;

[0009] In the compound of formula I or formula II, R1 and R2 are each independently selected from any one of -H, C6-C40 aryl or C6-C30 heteroaryl, and at least one of R1 and R2 is not selected from -H; the hydrogen atoms in R1 and R2 are each independently substituted by C6-C20 aryl;

[0010] In the compound of formula II, R3 is selected from C6-C40 aryl or C6-C30 heteroaryl;

[0011] In the compound of formula I or formula II, X is independently selected from C or Si;

[0012] The hydrogen atoms in the compound of formula I and the compound of formula II may each independently be substituted by at least one of -D, -F, -CN, C1-C12 alkyl or C1-C12 alkoxy.

[0013] In the present invention, the structure of the carbazole compound is designed, and the structure contains Group and In comparison, the two benzene rings in the compound of the present invention are connected by a single bond, which makes the molecule more rigid and reduces the energy loss of the molecule due to vibration. When it is used as the main material of the light-emitting layer of an organic electroluminescent device, its energy can be better transferred to the dye (doping, Dopant), so that the organic electroluminescent device has a higher current efficiency and a longer life. And through the selection of Ar1, the steric hindrance of the entire molecule is increased, T1 is increased, and it is more suitable for use as the main material of the light-emitting layer of an organic electroluminescent device.

[0014] Its structure contains The benzene rings are connected in the meta position:

[0015] And the connection method using the opposite position In comparison, the charge transport performance of the compound in the present invention is further improved, and the compound is more suitable for being used as a main material of the light-emitting layer of an organic electroluminescent device.

[0016] In the present invention, C6-C40 can be C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.

[0017] C6-C30 can be C6, C8, C10, C12, C16, C20, C24, C28 or C30, etc.

[0018] C6-C20 can be C6, C8, C10, C12, C16 or C20, etc.

[0019] C1-C12 can be C1, C2, C4, C6, C8, C10 or C12, etc.

[0020] It should be noted that, in the present invention, "-D" represents a deuterium atom, and the same applies hereinafter.

[0021] 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.

[0022] As a preferred technical solution of the present invention, the C6-C40 aromatic group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, naphthylphenyl, anthracenyl, phenanthryl, fluorenyl, benzofluorenyl, dibenzofluorenyl, naphthanofluorenyl, pyrene, perylenyl, spirofluorenyl, triphenylene, fluoranthenyl, hydrogenated benzanthryl, indenofluorenyl, benzoindenofluorenyl, dibenzoindenofluorenyl, naphthanofluorenyl or benzonaphthofluorenyl.

[0023] Preferably, the C6-C30 heteroaryl group is selected from any one of carbazolyl, dibenzofuranyl, dibenzothiophenyl, naphthobenzofuranyl, naphthobenzothiophenyl, dinaphthofuranyl and dinaphthothiophenyl.

[0024] Preferably, the C6-C20 aryl group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, fluorenyl, triphenylene and fluoranthene.

[0025] Preferably, the C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl or decyl.

[0026] Preferably, the C1-C12 alkoxy group is selected from any one of methoxy, ethoxy, propoxy, butoxy, pentyloxy or hexyloxy.

[0027] As a preferred technical solution of the present invention, in the compound of formula I or formula II, Ar2 is independently selected from any one of phenyl, carbazolyl, biphenyl, fluorenyl, naphthyl, triphenylene, fluoranthene, indenyl, dibenzofuranyl, dibenzothienyl, naphthiobenzofuranyl or naphthiobenzothienyl.

[0028] Preferably, in the compound of formula I or formula II, the Ar2 is independently selected from any one of phenyl, naphthyl, biphenyl, triphenylene, 9,9-dimethylfluorenyl, carbazolyl, dibenzofuranyl and dibenzothiophenyl.

[0029] Preferably, in the compound of formula I or formula II, the Ar2 is independently selected from any one of phenyl, naphthyl or biphenyl.

[0030] As a preferred technical solution of the present invention, in the compound of formula I or formula II, R1 and R2 are each independently selected from any one of -H, phenyl, carbazolyl, biphenyl, fluorenyl, naphthyl, triphenylene, fluoranthene, indenofluorenyl, dibenzofuranyl, dibenzothienyl, naphthiobenzofuranyl or naphthiobenzothienyl, and at least one of R1 and R2 is not selected from -H.

[0031] Preferably, in the compound of formula I or formula II, R1 and R2 are each independently selected from any one of -H, phenyl, naphthyl, biphenyl, 9,9-dimethylfluorenyl, carbazolyl, dibenzofuranyl, and dibenzothiophenyl, and at least one of R1 and R2 is not selected from -H.

[0032] Preferably, the hydrogen atoms in R1 and R2 can be independently substituted by any one of phenyl, naphthyl and biphenyl.

[0033] Preferably, in the compound of formula I or formula II, R1 and R2 are each independently selected from any one of -H, carbazolyl, phenyl, naphthyl, biphenyl, phenyl-substituted carbazolyl, dibenzofuranyl, and phenyl-substituted dibenzofuranyl, and at least one of R1 and R2 is not selected from -H.

[0034] As a preferred technical solution of the present invention, in the compound of formula II, R3 is selected from any one of phenyl, carbazolyl, biphenyl, fluorenyl, naphthyl, triphenylene, fluoranthenyl, indenofluorenyl, dibenzofuranyl, dibenzothienyl, naphthiobenzofuranyl or naphthiobenzothienyl.

[0035] Preferably, in the compound of formula II, R3 is selected from any one of phenyl, naphthyl, biphenyl, 9,9-dimethylfluorenyl, carbazolyl, dibenzofuranyl, and dibenzothiophenyl, and is more preferably phenyl or biphenyl.

[0036] As a preferred technical solution of the present invention, the hydrogen atoms in the compound of formula I and the compound of formula II can be independently substituted by at least one of -D, methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy or butoxy.

[0037] Preferably, the hydrogen atoms in the compound of formula I and the compound of formula II can be independently substituted by at least one of -D, -F, -CN, methyl, tert-butyl, methoxy and propoxy.

[0038] As a preferred technical solution of the present invention, the carbazole compound is selected from the following substituted or unsubstituted compounds:

[0039]

[0040]

[0041]

[0042] The substitution means that the hydrogen atoms in the above compounds can each be independently replaced by a deuterium atom.

[0043] Preferably, the carbazole compounds also include compounds in which the Si atoms in the above compounds are replaced by C atoms, that is, The group is replaced by The dotted line represents the attachment site.

[0044] As compound middle The group is replaced by Compound

[0045]

[0046] Preferably, the carbazole compound is selected from any one of the following compounds:

[0047]

[0048]

[0049] It should be noted that the present invention does not have any special limitation on the preparation method of carbazole compounds, and all commonly used preparation methods in the art are applicable.

[0050] In a second aspect, 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;

[0051] The organic thin film layer includes the carbazole compound as described in the first aspect.

[0052] As a preferred technical solution of the present invention, the organic thin film layer includes a light-emitting layer;

[0053] The main material of the light-emitting layer includes the carbazole compound as described in the first aspect.

[0054] Preferably, the light-emitting layer is a phosphorescent light-emitting layer.

[0055] As a preferred technical solution of the present invention, the organic electroluminescent device is a blue light organic electroluminescent device.

[0056] The luminescent layer in the present invention includes a luminescent layer main material and a doping material, wherein the doping material is also called a dye or a phosphorescent luminescent material. The luminescent layer main material can be a single compound or a mixture of two or more compounds.

[0057] 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.

[0058] The volume percentage of the main material in the phosphorescent 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%.

[0059] In the present invention, the doping material of the light-emitting layer may be a phosphorescent material, which is also called a triplet light-emitting material, and refers to the light emitted from a triplet excited state. The specific selection of the phosphorescent material in the present invention is not particularly limited, and the doping materials of the light-emitting layer commonly used in the art are applicable, including but not limited to: a compound having a structure shown in Formula PD:

[0060]

[0061] Wherein, M is selected from any one of Ir, Pt, Pd, Os, Ti, Zr, Hf, Eu, Tb, Tm, Cu or Au;

[0062] Y1-Y4 are each independently selected from carbon or nitrogen;

[0063] 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;

[0064] Cy1 and Cy2 are each independently selected from phenyl, naphthyl, fluorenyl, spirofluorenyl, indenyl, pyrrolyl, thienyl, furanyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, quinolyl, isoquinolyl, benzoquinolyl, quinoxalinyl, quinazolinyl, carbazolyl, benzimidazolyl, benzofuranyl, benzothienyl, isobenzothienyl, benzimidazolyl, benzoxazolyl, triazolyl, tetrazolyl, oxadiazolyl, triazine, dibenzofuranyl, dibenzothienyl, N-heterocarbazolyl, N-heterodibenzofuranyl, wherein Cy1 and Cy2 may be optionally linked to each other via a single bond or an organic linking group;

[0065] 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;

[0066] R 91 and R 92each 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 (e.g., C1, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) alkyl, substituted or unsubstituted C2-C6 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, C2, C3, C4, C5, C6, C7, C8, C9 or C10) 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.

[0067] a1 and a2 are each independently an integer selected from 1-5, for example, 1, 2, 3, 4 or 5;

[0068] b is an integer selected from 0-4, for example, 0, 1, 2, 3 or 4;

[0069] a is selected from 1, 2 or 3;

[0070] L1 is a monovalent organic ligand, a divalent organic ligand or a trivalent organic ligand.

[0071] Preferably, the compound of formula PD is selected from any one of the following compounds:

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078] 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.

[0079] The hole injection layer material includes a P-type dopant. The P-type dopant refers to a dopant that coexists with the hole injection layer material in the OLED device and can oxidize the hole injection layer material, thereby acting as an electron acceptor and promoting the movement of holes in the hole injection layer to 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 more preferably greater than 0.2eV.

[0080] The P-type dopant is present in the hole injection layer in 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, and illustratively, the compounds D-1 to D-13 disclosed in CN113728453A or the compounds HI-1 to HI-9 described below can be selected:

[0081]

[0082]

[0083] 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:

[0084]

[0085] 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;

[0086] 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;

[0087] 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 (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, fluoranthene, 9,9-dimethylfluorenyl, biphenyl, substituted or unsubstituted dibenzofuranyl (the substituted substituent is phenyl), substituted or unsubstituted dibenzothienyl (the substituted substituent is phenyl), dibenzofuran-substituted thienyl, C1-C6 (for example, C1, C2, C3, C4, C5 or C6) alkyl, any one of R 41 , R 42 They can be linked to form rings via single bonds.

[0088] The compound of formula HT-GH4 is selected from any one of the following compounds:

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095] In the present invention, the hole layer material (including the hole injection layer, the hole transport layer and the electron blocking layer) also includes a compound having a structure shown in the following formula IA or a compound having a structure shown in the following formula IB:

[0096]

[0097] Wherein, L is selected from any one of C6-C40 (for example, C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) arylene, dibenzofuranyl or dibenzothiophenyl;

[0098] 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;

[0099] Ar is selected from any one of triphenylene, fluoranthenylene, dibenzofuranylene or dibenzothiophenylene;

[0100] 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;

[0101] 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.

[0102] 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, etc.) alkyl group, 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;

[0103] H in the compound of formula IB and the compound of formula IA can each independently be replaced by at least one of -F, -CN, -D (deuterium atom), C1-C6 alkyl, C1-C6 alkoxy, phenyl, biphenyl, naphthyl, phenanthryl, anthracenyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, triphenylene, fluoranthenyl, pyrenyl, perylenyl, spirofluorenyl, indenofluorenyl or hydrogenated benzanthryl.

[0104] Preferably, Ar is a fluoranthenyl group, and m+n>1.

[0105] 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 fluoranthene.

[0106] Preferably, L, Ar1, Ar2 are each independently selected from at least one of phenyl, biphenyl, naphthyl, phenanthryl, anthracenyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, triphenylene, fluoranthenyl, pyrene, perylenyl, spirofluorenyl, indenofluorenyl or hydrogenated benzanthryl.

[0107] Preferably, the compound of formula IB is selected from the following structures:

[0108]

[0109] Wherein, L is phenylene;

[0110] Ar1, Ar2, and m have the same protection scope as described above.

[0111] Preferably, the compound of formula IB is selected from any one of the following compounds 1-112:

[0112]

[0113]

[0114]

[0115]

[0116]

[0117] In the OLED device provided by the present invention, the hole layer material may include conventional hole materials in the art in addition to the compound described in formula HT-GH4, the compound of formula IB, and the compound of formula IA, without special restrictions. Exemplary includes but is 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 (smaller absolute value), and is 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.

[0118] The triarylamine compound or the carbazole compound is used as the hole layer material, and the hole layer material includes the following structure:

[0119]

[0120] Among them, Ar 601 ~Ar 609Each independently selected from a substituted or unsubstituted C6-40 (for example, C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) aryl, a substituted or unsubstituted dibenzofuranyl, a substituted or unsubstituted dibenzothiophenyl, a substituted or unsubstituted naphthobenzofuranyl, a substituted or unsubstituted naphthobenzothiophenyl, a substituted or unsubstituted dinaphthofuranyl, a substituted or unsubstituted dinaphthothiophenyl;

[0121] 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;

[0122] 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 , R 702 Can connect via one-touch.

[0123] The hole blocking layer (HBL) can confine holes and / or excitons within the EL to improve the current efficiency and lifetime of the device. Compared with the EL material closest to the HBL interface, the HBL material has a lower HOMO (larger absolute value) and / or higher triplet energy.

[0124] 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. The general 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-coffee structure, an N-carbazole structure, an N-dibenzofuran structure, and an N-dibenzothiophene structure.

[0125] In the present invention, there is no special restriction on the electron transport layer material, which exemplarily includes but is not limited to:

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134] In the present invention, the material of the cathode is a metal with a low work function (e.g., alkaline earth metal, alkali metal, main group metal or lanthanide element (e.g., Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.)), a metal alloy composed of multiple metals (alloy composed of alkali metal or alkaline earth metal 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 functions, such as Ag or Al, can also be used. In this case, a combination of the metals is usually used, such as Ca / Ag, Mg / Ag or Ba / Ag.

[0135] It is also possible to introduce a thin intermediate layer of a material with a high dielectric constant between the metal cathode and the organic semiconductor to form a multilayer structure; the material with a high dielectric constant can also be called an electron injection material, and fluorides of alkali metals or alkaline earth metals, and corresponding oxides or carbonates (such as LiF, Li2O, BaF2, MgO, NaF, CsF, Cs2CO3, etc.) or lithium quinoline (LiQ) can be selected.

[0136] Compared with the prior art, the present invention has the following beneficial effects:

[0137] The invention designs the structure of the carbazole compound so that the compound is suitable for being used as the main material of the light-emitting layer of the organic electroluminescent device, so that the organic electroluminescent device has higher current efficiency and longer life. DETAILED DESCRIPTION

[0138] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0139] Example 1

[0140] This example provides compound P1, the synthesis method of which is as follows:

[0141]

[0142] Under a nitrogen atmosphere, dry toluene (80 mL), compound P1-1 (4.1 g), compound P1-2 (3.4 g), Pd(dba)2 (bis(dibenzylideneacetonepalladium, 0.1 g), 10% tri-tert-butylphosphine toluene solution (the mass of tri-tert-butylphosphine solution is 0.8 g) and sodium tert-butoxide (1.2 g) were added to a three-necked flask, and the reaction was heated to reflux for 8 h. The mixture was cooled to room temperature, and water was added to separate the mixture. The organic layer was then washed with water until it was neutral, dried over magnesium sulfate, filtered to remove the magnesium sulfate, concentrated to dryness, and separated by silica gel column chromatography with petroleum ether:ethyl acetate = 20:1 (volume ratio) to obtain compound P1 (5.3 g).

[0143] The mass spectrometry detection of compound P1: the mass-to-charge ratio (m / z) was measured to be 664.23.

[0144] Example 2-11

[0145] Examples 2-11 provide a compound respectively. The synthesis method of the compound can refer to the synthesis method of compound P1 provided in Example 1, and the corresponding raw materials are used to react to prepare the corresponding compound, as shown in Table 1 below.

[0146] The obtained compounds were subjected to mass spectrometry detection, and the mass-to-charge ratio (m / z) data are shown in Table 1 below.

[0147] Table 1

[0148]

[0149]

[0150]

[0151] Example 12

[0152] This example provides compound P14, the synthesis method of which is as follows:

[0153]

[0154] Under nitrogen atmosphere, 120 mL of toluene was added to a three-necked flask, followed by 4.1 g of compound P1-1, 5.5 g of compound P14-2, 2.12 g of sodium carbonate and 0.1 g of dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium (II) (CAS No. 887919-35-9), and the temperature was slowly raised to reflux for reaction for 4 hours. The temperature was lowered to room temperature, and water was added to separate the organic layer. The organic layer was washed with water and dried over magnesium sulfate. After removing the desiccant, the mixture was concentrated to dryness and separated by silica gel column chromatography. The mixture was eluted with petroleum ether:ethyl acetate = 10:0.5 (volume ratio) to obtain compound P14 (6.8 g).

[0155] The obtained compound P14 was subjected to mass spectrometry detection, and the mass-to-charge ratio (m / z) was measured to be 816.30.

[0156] Other compounds whose specific synthesis methods are not listed can be synthesized by referring to the above embodiments in combination with common knowledge in the art.

[0157] The specific structures of some compositions used in the following application examples and comparative application examples are as follows:

[0158]

[0159]

[0160]

[0161] Wherein, the synthesis method of compound D2 is as follows:

[0162]

[0163] Referring to the synthesis of compound P14, compound D2 was obtained by changing the starting materials.

[0164] The obtained compound D2 was subjected to mass spectrometry detection, and the mass-to-charge ratio (m / z) was measured to be 816.30.

[0165] Application Example 1

[0166] This application example provides a blue light organic electroluminescent device, using the compound P1 provided by the present invention as a main material of the light-emitting layer, and the structure of the blue light organic electroluminescent device is:

[0167] ITO / HT-1: HI-2 [5%] (70nm) / HT-1 (35nm) / host material: PBD-1 [5%] (35nm) / ETL-1 (25nm) / LiF (0.5nm) / Al (150nm).

[0168] The preparation method of the blue light organic electroluminescent device is as follows:

[0169] The material was placed in a vacuum chamber and evacuated to 1×10 -5 ~1×10 -6 Pa was vacuum evaporated onto the cleaned ITO substrate in turn to prepare an OLED device.

[0170] 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 a hole transport material; HT-1:HI-2[5%] are used as materials for forming a hole injection layer.

[0171] Application Example 2-13

[0172] Application Examples 2-13 each provide an organic electroluminescent device, which differs from Application Example 1 only in that the main material compound P1 of the light-emitting layer is replaced with other compounds (see Table 2 below for details), and the other preparation steps and conditions are the same as those of Application Example 1.

[0173] Comparative Application Examples 1-3

[0174] Comparative Application Examples 1-3 respectively provide an organic electroluminescent device, which differs from Application Example 1 only in that the main material compound P1 of the light-emitting layer is replaced with other compounds, and the dye PBD-1 is replaced as needed (see Table 2 below for details), and the other preparation steps and conditions are the same as those of Application Example 1.

[0175] Performance Testing

[0176] 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, where the current efficiency and LT95 are relative values. The specific test results are shown in Table 2 below:

[0177] Table 2

[0178] Main material dye <![CDATA[Luminance / (cd / m 2 )]]> Current efficiency LT95 Application Example 1 P1C PBD-1 1000 1.06 1.11 Application Example 2 P1 PBD-1 1000 1.04 1.22 Application Example 3 P2 PBD-1 1000 1.08 1.07 Application Example 4 P3 PBD-1 1000 1.18 1.68 Application Example 5 P4 PBD-1 1000 1.25 / Application Example 6 P5 PBD-1 1000 1.09 1.11 Application Example 7 P7 PBD-1 1000 1.16 1.09 Application Example 8 P9 PBD-1 1000 1.29 1.25 Application Example 9 P10 PBD-1 1000 1.57 1.02 Application Example 10 P11 PBD-1 1000 1.27 / Application Example 11 P12 PBD-1 1000 1.08 1.26 Application Example 12 P13 PBD-1 1000 1.09 1.02 Application Example 13 P17 PBD-1 1000 1.05 1.16 Comparative application example 1 D1 PBD-1 1000 / 1 Comparative Application Example 2 D3 PBD-1 1000 1 / Comparative Application Example 3 H-4 PBD-1 1000 0.96 /

[0179] The “ / ” indicates that this data does not exist.

[0180] It can be seen from the above content that the present invention designs the structure of the carbazole compound to make it suitable as the main material of the light-emitting layer of the organic electroluminescent device, so that the organic electroluminescent device has higher current efficiency and longer life.

[0181] Application examples 14-16, comparative application examples 4-5

[0182] Application Examples 14-16 and Comparative Application Examples 4-5 respectively provide a blue light organic electroluminescent device, which differs from Application Example 1 only in that the main material compound P1 of the light-emitting layer is replaced with other compounds as needed (see Table 3 below for details), and the other preparation steps and conditions are the same as those of Application Example 1.

[0183] Performance Testing

[0184] 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, where the current efficiency and LT95 are relative values. The specific test results are shown in Table 3 below:

[0185] Table 3

[0186] Main material dye <![CDATA[Luminance / (cd / m 2 )]]> Current efficiency LT95 Application Example 14 P14 PBD-1 1000 1.22 1.11 Application Example 15 P15 PBD-1 1000 1.10 1.07 Application Example 16 P16 PBD-1 1000 1.09 1.28 Comparative Application Example 4 H-8 PBD-1 1000 1 1 Comparative Application Example 5 D2 PBD-1 1000 0.97 1.06

[0187] It can be seen from the above content that the present invention designs the structure of the carbazole compound to make it suitable as the main material of the light-emitting layer of the organic electroluminescent device, so that the organic electroluminescent device has higher current efficiency and longer life.

[0188] The applicant declares that the present invention illustrates the detailed process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process flow to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various 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 compound has a structure shown in the following formula I or formula II: Wherein, in the compound of formula I or formula II, Ar2 is independently selected from C6-C40 aryl or C6-C30 heteroaryl; In the compound of formula I or formula II, R1 and R2 are each independently selected from any one of -H, C6-C40 aryl or C6-C30 heteroaryl, and at least one of R1 and R2 is not selected from -H; the hydrogen atoms in R1 and R2 are each independently substituted by C6-C20 aryl; In the compound of formula II, R3 is selected from C6-C40 aryl or C6-C30 heteroaryl; In the compound of formula I or formula II, X is independently selected from C or Si; The hydrogen atoms in the compound of formula I and the compound of formula II may each independently be substituted by at least one of -D, -F, -CN, C1-C12 alkyl or C1-C12 alkoxy.

2. The carbazole compound according to claim 1, characterized in that The C6-C40 aryl group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, naphthylphenyl, anthracenyl, phenanthryl, fluorenyl, benzofluorenyl, dibenzofluorenyl, naphthofluorenyl, pyrenyl, peryl, spirofluorenyl, triphenylene, fluoranthenyl, hydrogenated benzanthryl, indenofluorenyl, benzoindenofluorenyl, dibenzoindenofluorenyl, naphthofluorenyl or benzonaphthofluorenyl; Preferably, the C6-C30 heteroaryl group is selected from any one of carbazolyl, dibenzofuranyl, dibenzothiophenyl, naphthobenzofuranyl, naphthobenzothiophenyl, dinaphthofuranyl and dinaphthothiophenyl; Preferably, the C6-C20 aryl group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, fluorenyl, triphenylene, and fluoranthenyl; Preferably, the C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl or decyl; Preferably, the C1-C12 alkoxy group is selected from any one of methoxy, ethoxy, propoxy, butoxy, pentyloxy or hexyloxy.

3. The carbazole compound according to claim 1 or 2, characterized in that In the compound of formula I or II, Ar2 is independently selected from any one of phenyl, carbazolyl, biphenyl, fluorenyl, naphthyl, triphenylene, fluoranthenyl, indenofluorenyl, dibenzofuranyl, dibenzothienyl, naphthobenzofuranyl or naphthobenzothienyl; Preferably, in the compound of formula I or formula II, the Ar2 is independently selected from any one of phenyl, naphthyl, biphenyl, triphenylene, 9,9-dimethylfluorenyl, carbazolyl, dibenzofuranyl, and dibenzothiophenyl; Preferably, in the compound of formula I or formula II, the Ar2 is independently selected from any one of phenyl, naphthyl or biphenyl.

4. The carbazole compound according to any one of claims 1 to 3, characterized in that In the compound of formula I or formula II, R1 and R2 are each independently selected from any one of -H, phenyl, carbazolyl, biphenyl, fluorenyl, naphthyl, triphenylene, fluoranthenyl, indenofluorenyl, dibenzofuranyl, dibenzothienyl, naphthobenzofuranyl or naphthobenzothienyl, and at least one of R1 and R2 is not selected from -H; Preferably, in the compound of formula I or formula II, R1 and R2 are each independently selected from any one of -H, phenyl, naphthyl, biphenyl, 9,9-dimethylfluorenyl, carbazolyl, dibenzofuranyl, and dibenzothiophenyl, and at least one of R1 and R2 is not selected from -H; preferably, R1 and R2 are each independently substituted by any one of phenyl, naphthyl, and biphenyl; Preferably, in the compound of formula I or formula II, R1 and R2 are each independently selected from any one of -H, carbazolyl, phenyl, naphthyl, biphenyl, phenyl-substituted carbazolyl, dibenzofuranyl, and phenyl-substituted dibenzofuranyl, and at least one of R1 and R2 is not selected from -H.

5. The carbazole compound according to any one of claims 1 to 4, characterized in that In the compound of formula II, R3 is selected from any one of phenyl, carbazolyl, biphenyl, fluorenyl, naphthyl, triphenylene, fluoranthenyl, indenofluorenyl, dibenzofuranyl, dibenzothienyl, naphthobenzofuranyl or naphthobenzothienyl; Preferably, in the compound of formula II, R3 is selected from any one of phenyl, naphthyl, biphenyl, 9,9-dimethylfluorenyl, carbazolyl, dibenzofuranyl, and dibenzothiophenyl, and is more preferably phenyl or biphenyl.

6. The carbazole compound according to any one of claims 1 to 5, characterized in that: The hydrogen atoms in the compound of formula I and the compound of formula II may be independently substituted by at least one of -D, methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy or butoxy; Preferably, the hydrogen atoms in the compound of formula I and the compound of formula II can be independently substituted by at least one of -D, -F, -CN, methyl, tert-butyl, methoxy and propoxy.

7. The carbazole compound according to any one of claims 1 to 6, characterized in that: The carbazole compound is selected from the following substituted or unsubstituted compounds: The substitution means that the hydrogen atoms in the above compounds can each independently be replaced by a deuterium atom; Preferably, the carbazole compounds also include compounds in which the Si atoms in the above compounds are replaced by C atoms.

8. 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 organic thin film layer comprises the carbazole compound according to any one of claims 1 to 7.

9. The organic electroluminescent device according to claim 8, characterized in that: The organic thin film layer includes a light-emitting layer; The host material of the light-emitting layer includes the carbazole compound according to any one of claims 1 to 7.

10. The organic electroluminescent device according to claim 8 or 9, characterized in that: The light-emitting layer is a phosphorescent light-emitting layer.

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