A carbazole compound, intermediate, composition and organic electroluminescent device

Abstract

The application provides a kind of carbazole compound, intermediate, composition and organic electroluminescent device.The carbazole compound has the structure of formula I.The application designs the structure of carbazole compound, so that it is suitable for being used as the host material of the light-emitting layer of organic electroluminescent device, so that the organic electroluminescent device has lower driving voltage, higher current efficiency and longer service life.

Description

Technical Field

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

[0002] The structure of an organic light-emitting diode (OLED) device specifically consists of an anode, a cathode, and an organic layer between them. To improve the efficiency and stability of OLED devices, the organic material layer comprises multiple layers with different materials, such as a hole injection layer (HIL), a hole transport layer (HTL), a hole blocking layer, an emissive layer, an electron transport layer (ETL), and an electron injection layer (EIL). Currently, organic light emission has become a mainstream display technology, and correspondingly, various novel OLED materials have been developed.

[0003] To meet the higher demands of people for OLED devices, there is an urgent need in the field to develop more types 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, intermediate, composition, and organic electroluminescent device. In this invention, the structure of the carbazole compound is designed to be suitable as the main material for the phosphorescent layer of an organic electroluminescent device, resulting in an organic electroluminescent device with lower driving voltage, higher current efficiency, and longer lifespan.

[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] Among them, Ar1 and Ar2 are selected from H, and the other is selected from any one of C6-C40 aryl or C6-C30 heteroaryl.

[0009] A1, A2, and A3 are each independently selected from N or CR, and at least one of them is selected from N;

[0010] R is selected from any one of H, -CN, C6-C20 aryl or C1-C12 alkyl;

[0011] n can be either 0 or 1.

[0012] In this invention, C6-C40 can be C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.

[0013] C6-C30 can be C6, C8, C10, C12, C16, C20, C24, C28, or C30, etc.

[0014] C6-C20 can be C6, C8, C10, C12, C16, or C20, etc.

[0015] C1-C12 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12.

[0016] It should be noted that in this invention, "D" represents a deuterium atom, and the same applies below.

[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. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0018] As a preferred embodiment of the present invention, the carbazole compound has the structure shown in Formula I-1:

[0019]

[0020] Among them, Ar1 and Ar2 are selected from H, and the other is selected from any one of C6-C40 aryl or C6-C30 heteroaryl.

[0021] A1, A2, and A3 are each independently selected from N or CR, and at least one of them is selected from N;

[0022] R is selected from any one of H, -CN, C6-C20 aryl or C1-C12 alkyl;

[0023] n can be either 0 or 1.

[0024] As a preferred embodiment of the present invention, the C6-C40 aryl group is selected from any one or a combination of at least two of the following: phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, fluorenyl, benzo[a]fluorenyl, dibenzo[a]fluorenyl, naphthyl, pyrene, perylene, spirofluorenyl, triphenylene, fluoranyl, hydrogenated benzo[a]anthrayl, ind[a]fluorenyl, benzo[a]ind[a]fluorenyl, dibenzo[a]ind[a]fluorenyl, naphthyl, tetraphenylmethane, or benzo[a]naphthyl.

[0025] As a preferred embodiment of the present invention, the C6-C30 heteroaryl group is selected from any one or a combination of at least two of carbazolyl, dibenzothiophenel, dibenzofuranyl, naphthobenzofuranyl, naphthobenzothiophenel, dinaphthofuranyl, and dinaphthothiophenel.

[0026] Preferably, the C6-C20 aryl group is selected from any one of phenyl, naphthyl, biphenyl, anthracene, phenanthryl, fluorenyl, triphenylene, or fluoranthracene.

[0027] Preferably, the C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, n-butyl, tert-butyl, cyclopentyl, cyclohexyl, octyl, and adamantyl.

[0028] As a preferred embodiment of the present invention, one of Ar1 and Ar2 is selected from H, and the other is selected from at least one of phenyl, carbazolyl, naphthyl, 9,9-dimethylfluorenyl, dibenzothiophene, biphenyl, dibenzofuranyl, triphenylene or fluoranyl.

[0029] Preferably, one of Ar1 and Ar2 is selected from H, and the other is selected from phenyl or biphenyl.

[0030] As a preferred embodiment of the present invention, one of A1, A2, and A3 is selected from N, and the other two are selected from CR, wherein R is selected from H.

[0031] As a preferred embodiment of the present invention, two of A1, A2, and A3 are selected from N, and the other is selected from CR, wherein R is selected from H.

[0032] As a preferred embodiment of the present invention, A1, A2, and A3 are all selected from N.

[0033] In a preferred embodiment of the present invention, n is selected from 0.

[0034] In a preferred embodiment of the present invention, n is selected from 1.

[0035] As a preferred embodiment of the present invention, the carbazole compound is selected from any one of the following substituted or unsubstituted compounds:

[0036]

[0037] The substitution refers to the independent replacement of each hydrogen atom in the aforementioned carbazole compounds by a deuterium atom.

[0038] Preferably, the carbazole compound is selected from any one of the following compounds:

[0039]

[0040] It should be noted that the present invention does not impose any special limitations on the preparation methods of the above-mentioned carbazole compounds, and commonly used preparation methods in the art are applicable. For example, the preparation method of the compound of formula I provided by the present invention is as follows:

[0041]

[0042]

[0043] Ar1, Ar2, A1, A2, A3, and n have the same definitions as above;

[0044] X1 and X2 are each independently selected from any one of fluorine, chlorine, bromine or iodine.

[0045] In a second aspect, the present invention provides an intermediate comprising a compound having a structure as shown in the formula MA:

[0046]

[0047] X1 is selected from any one of fluorine, chlorine, bromine, and iodine;

[0048] Ar1, Ar2, and n have the same definitions as above;

[0049] The intermediate is used to prepare carbazole compounds as described in the first aspect.

[0050] Preferably, the intermediate comprises the following compounds:

[0051]

[0052] Thirdly, the present invention provides a composition comprising a first component and a second component;

[0053] The first component includes carbazole compounds as described in the first aspect;

[0054] The second component includes compound A;

[0055] Compound A is obtained by fusion of a group with the structure shown in Formula IA and any two adjacent carbon atoms on ring A in the group with the structure shown in Formula IB:

[0056]

[0057] Where * represents a fusion site;

[0058] X is selected from O, S, R 301 R 302 Each is independently selected from C1-C6 alkyl, C6-C30 aryl, or C6-C20 heteroaryl, and R 301 R 302 A ring can be formed by connecting with a single key, R 303 Selected from C6-C30 aryl or C6-C20 heteroaryl, with dashed lines indicating connection sites;

[0059] Ar 22Selected from C6-C30 aryl or C6-C20 heteroaryl;

[0060] In compound A, each hydrogen atom can be independently substituted by at least one of -F, -CN, C6-C20 aryl, C1-C6 alkyl, and C1-C6 alkoxy.

[0061] In compound A, C6-C30 can be C6, C10, C12, C18, C24, or C30, etc.

[0062] The C6-C20 can be C6, C10, C12, C18, or C20, etc.

[0063] The C1-C6 can be C1, C2, C3, C4, C5 or C6.

[0064] As a preferred technical solution of the present invention, the R 303 Ar 22 Each group is independently selected from any one or a combination of at least two of the following substituted or unsubstituted groups: phenyl, biphenyl, naphthyl, anthracene, phenanthrene, fluorenyl, benzo[a]fluorenyl, dibenzo[a]fluorenyl, triphenylene, fluoranyl, pyrene, perylene, spirofluorenyl, dibenzofuranyl, dibenzothiophene, naphthobenzofuran, naphthobenzothiophene, dinaphthofuran, dinaphthothiophene, hydrogenated benzene Anthrayl, indo-carbazolyl, indo-carbazolyl, terphenyl, tetraphenyl, imidazolyl, benzimidazolyl, pyridyl, pyrimidinyl, piperazine, quinolinyl, isoquinolinyl, quinoxalinyl, quinazolinyl, benzoquinoxalinyl, benzoquinoxalinyl, N-phenanthroline, diazanthroline, carbazolyl, benzo-carbazolyl, naphtho-carbazolyl, dibenzo-carbazolyl, triazine;

[0065] The substituents are each independently selected from at least one of C1-C12 (e.g., C1, C2, C5, C6, C8, C10, or C12), C1-C12 (e.g., C1, C2, C5, C6, C8, C10, or C12), and C6-C12 (e.g., C6, C7, C8, C9, C10, C11, or C12) aryl groups.

[0066] As a preferred technical solution of the present invention, the R 303 Ar 22 Each group is independently selected from any one or a combination of at least two of the following substituted or unsubstituted groups: phenyl, biphenyl, naphthyl, phenanthryl, anthracene, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, spirofluorenyl, dibenzofuranyl, dibenzothiopheneyl, triphenylene, fluorenyl, benzofluorenyl, carbazoleyl;

[0067] The substituent is selected from at least one of methyl, ethyl, tert-butyl, adamantyl, cyclohexyl, cyclopentyl, 1-methylcyclopentyl, 1-methylcyclohexyl, methoxy, phenyl, biphenyl, 9,9-dimethylfluorenyl, dibenzofuranyl, dibenzothiophene, or naphthyl.

[0068] Preferably, X is selected from O and S.

[0069] Preferably, the R 301 R 302 Each is independently selected from methyl or phenyl.

[0070] Preferably, the R 303 It is selected from any one of phenyl, diphenyl, or triphenyl.

[0071] Preferably, the Ar 22 It is selected from any one of biphenyl, terphenyl, or tetraphenyl.

[0072] Preferably, the R 303 The Ar is a phenyl group. 22 It is selected from any one of biphenyl, terphenyl, or tetraphenyl.

[0073] Preferably, the R 303 It is a diphenyl group, and the Ar is... 22 Selected from diphenyl or triphenyl.

[0074] As a preferred embodiment of the present invention, compound A has a structure as shown in formulas I-1 to I-30: and each of the compounds shown in formulas I-1 to I-30 can be independently substituted by at least one of -F, -CN, C6-C20 (e.g., C6, C10, C12, C18 or C20, etc.) aryl, C1-C6 (e.g., C1, C2, C3, C4, C5 or C6) alkyl, and C1-C6 (e.g., C1, C2, C3, C4, C5 or C6) alkoxy.

[0075]

[0076] Among them, R 303 Ar 22 It has the same scope of protection as described above.

[0077] As a preferred embodiment of the present invention, compound A is selected from any one of the following compounds:

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093] Preferably, compound A is selected from any one of the following compounds:

[0094]

[0095]

[0096]

[0097] It should be noted that there are no special restrictions on the preparation method of the above-mentioned compound A in this invention, and commonly used preparation methods in the art are applicable.

[0098] Fourthly, 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;

[0099] The organic thin film layer material includes carbazole compounds as described in the first aspect and / or compositions as described in the third aspect.

[0100] As a preferred embodiment of the present invention, the organic thin film layer includes a light-emitting layer, and the main material of the light-emitting layer includes carbazole compounds as described in the first aspect and / or compositions as described in the third aspect.

[0101] Preferably, the light-emitting layer is a phosphorescent light-emitting layer.

[0102] As a preferred embodiment of the present invention, the organic electroluminescent device is a green organic electroluminescent device.

[0103] In this invention, the light-emitting layer comprises a host material and a dopant material, wherein the dopant material is also called a dye or a phosphorescent material. The host material of the light-emitting layer can be a single compound or a mixture of two or more compounds.

[0104] The light-emitting layer includes a phosphorescent light-emitting layer, which 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.

[0105] The volume percentage of the main material in the phosphorescent luminescent layer is 60% to 99.9% (e.g., it can be 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99.9%), preferably 70% to 99.5%, and more preferably 85% to 95%.

[0106] In this invention, the doping material of the light-emitting layer can be a phosphorescent material, also known as a triplet luminescent material, which refers to the light emitted by a substance from a triplet excited state. The specific selection of phosphorescent materials in this invention is not particularly limited; commonly used doping materials for the light-emitting layer in this field are applicable, including but not limited to compounds having the structure shown in the formula PD.

[0107]

[0108] Wherein, M is selected from any one of Ir, Pt, Pd, Os, Ti, Zr, Hf, Eu, Tb, Tm, Cu or Au;

[0109] Y1-Y4 are each independently selected from carbon or nitrogen;

[0110] 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.

[0111] 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, dibenzothiopheneyl, and n-hexacarbazolyl, wherein Cy1 and Cy2 may optionally be linked to each other via a single bond or an organic linking group;

[0112] 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.

[0113] R 91 and R 92 Each 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., can be C1, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55, or C60, etc.) 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, etc.) 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, C40, C50, C55, C60, etc.) alkyne, substituted or unsubstituted C1-C60 (e.g., can be C1, C5, C10, C15, C20, C50, C10, C15, C20, C1 ... 25. alkoxy, substituted or unsubstituted C2-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, or C10), heterocyclic alkyl, substituted or unsubstituted C6-C60 (e.g., 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: aryloxy group (C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60, etc.), substituted or unsubstituted C6-C60 (e.g., it can be C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60, etc.), substituted or unsubstituted monovalent non-aromatic fused polycyclic group, or substituted or unsubstituted monovalent non-aromatic fused heterocyclic group.

[0114] a1 and a2 are each independent integers selected from 1 to 5, for example, they can be 1, 2, 3, 4 or 5;

[0115] b is an integer selected from 0 to 4, for example, it can be 0, 1, 2, 3 or 4;

[0116] a is selected from 1, 2, or 3;

[0117] L1 can be a monovalent organic ligand, a divalent organic ligand, or a trivalent organic ligand.

[0118] Preferably, the PD compound is selected from any one of the following compounds:

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125] In this invention, the organic thin film layer includes a hole layer, which comprises a hole injection layer, a hole transport layer, and an electron blocking layer.

[0126] The hole injection layer material includes a P-type dopant. A P-type dopant is a material that coexists with the hole injection layer material in the OLED device, oxidizing the hole injection layer material and thus acting as an electron acceptor to promote the movement of holes from the hole injection layer to the anode. In this 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.

[0127] The P-type dopant exists in the hole injection layer at a volume percentage of 1% to 10% (e.g., 1%, 2%, 4%, 6%, 8%, or 10%). In this invention, no particular limitation is made on the type of P-type dopant; exemplarily, compounds D-1 to D-13 disclosed in CN113728453A or compounds HI-1 to HI-9 as described below can be used.

[0128]

[0129] In this invention, the hole layer material (including a hole injection layer, a hole transport layer, and an electron blocking layer) has the structure shown in the following formula HT-GH4:

[0130]

[0131] Among them, L 41Selected from single-bonded, C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40, etc.) aryl, and C6-C20 (e.g., C6, C8, C10, C12, C16, or C20, etc.) heteroaryl;

[0132] 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, etc.) aryl and C6-C20 (e.g., C6, C8, C10, C12, C16, or C20, etc.) heteroaryl;

[0133] 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, naphthyl, triphenylene, fluoranyl, 9,9-dimethylfluorenyl, biphenyl, substituted or unsubstituted group (the substituent is phenyl), substituted or unsubstituted dibenzothiophene (the substituent is phenyl), substituted thiophene, 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.

[0134] The HT-GH4 compound is selected from any one of the following compounds:

[0135]

[0136]

[0137] In this invention, the hole layer material (including a hole injection layer, a hole transport layer, and an electron blocking layer) further includes a compound having a structure as shown in Formula IA or a compound having a structure as shown in Formula IB:

[0138]

[0139] Wherein, L is selected from any one of C6-C40 (e.g., it can be C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) arylene, dibenzofuranyl or dibenzothiophene group;

[0140] m is selected from an integer between 0 and 4 (for example, it can be 0, 1, 2, 3 or 4), and n is selected from 0 or 1;

[0141] Ar is selected from any one of triphenylene, fluorene anthracene, dibenzofuranyl or dibenzothiophene;

[0142] Ar1 and Ar2 are each independently selected from any one of aryl, dibenzofuran, or dibenzothiophene groups containing C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40, etc.);

[0143] Ar1 and Ar, Ar2 and Ar, and Ar1 and Ar2 can be independently connected or bridged by single bonds, O, S, CR1R2, NR.

[0144] R, R1, and R2 are each independently selected from any one of the following: C1-C20 (e.g., C1, C2, C4, C6, C8, C10, C12, C14, C16, C18, or C20), alkyl, C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40), aryl, dibenzofuranyl, or dibenzothiopheneyl.

[0145] In compounds of formula IB and formula IA, the H can be independently replaced by at least one of -F, -CN, -D (deuterium atom), C1-C6 alkyl, C1-C6 alkoxy, phenyl, biphenyl, naphthyl, phenanthryl, anthracene, fluorenyl, benzo[a]fluorenyl, dibenzo[a]fluorenyl, triphenylene, fluoranyl, pyrene, perylene, spirofluorenyl, indo[a]fluorenyl, or hydrogenated benzo[a]anthryl.

[0146] Preferably, the Ar is fluoreneanthracene, where m+n>1.

[0147] Preferably, the H in the compounds of formula IB and formula IA can be replaced by at least one of -F, -CN, -D, C1-C3 alkyl (e.g., methyl, ethyl, or propyl), C1-C3 alkoxy (e.g., methoxy, ethoxy, or propoxy), phenyl, biphenyl, triphenylene, and fluoranthyl.

[0148] Preferably, L, Ar1, and Ar2 are each independently selected from at least one of phenyl, biphenyl, naphthyl, phenanthryl, anthracene, fluorenyl, benzo[a]fluorenyl, dibenzo[a]fluorenyl, triphenylene, fluoranyl, pyrene, perylene, spirofluorenyl, indo[a]fluorenyl, or hydrogenated benzo[a]anthryl.

[0149] Preferably, the compound of formula IB is selected from any one of the following compounds 1-112:

[0150]

[0151]

[0152] In the OLED device provided by this invention, the hole layer material, in addition to the compounds described in formula HT-GH4, formula IB, and formula IA, may also include conventional hole materials in the art, without particular limitation. Exemplarily, it includes, but is not limited to, triarylamine compounds or carbazole compounds. Preferably, triarylamine compounds or carbazole compounds containing three or more nitrogen atoms are preferred because they have a higher HOMO (lower absolute value) and are more suitable as hole injection layer materials. Triarylamine compounds or carbazole compounds containing two or one nitrogen atom can be used as hole transport layer materials. Some compounds or carbazole compounds containing one nitrogen atom, if they have a high LUMO, can also be used as electron blocking layer materials.

[0153] The triaryl amine compound or carbazole compound is used as the hole layer material, and the hole layer material includes the following structure:

[0154]

[0155] Among them, Ar 601 ~Ar 609 Each is independently selected from any one of the following: substituted or unsubstituted C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40, etc.) aryl, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted naphthobenzofuran, substituted or unsubstituted naphthobenzothiophene, substituted or unsubstituted dinaphthofuran, substituted or unsubstituted dinaphthothiophene;

[0156] And Ar 601 ~Ar 609 Ar atoms that are adjacent to or connected to the same N atom 601 ~Ar 609 It can be connected via a single key or via O, S, CR 701 R 702 NR703 bridging;

[0157] R 701 R 702 R 703 Selected from C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40, etc.) aryl, C6-C20 (e.g., C6, C8, C10, C12, C16, or C20, etc.) heteroaryl, C1-C6 (e.g., C1, C2, C3, C4, C5, or C6) alkyl, and R 701 R 702 It can be connected with a single button.

[0158] 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.

[0159] 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-phenanthion, N-carbazole, and N-dibenzothiophene.

[0160] In this invention, no special restrictions are placed on the electron transport layer material, which includes, but is not limited to, the following:

[0161]

[0162]

[0163] 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, etc.)), 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.

[0164] Alternatively, a thin interlayer of material with a high dielectric constant can be introduced 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 can be an alkali metal or alkaline earth metal fluoride, as well as the corresponding oxide or carbonate (e.g., LiF, Li2O, BaF2, MgO, NaF, CsF, Cs2CO3, etc.) or lithium quinoline (LiQ).

[0165] Compared with the prior art, the present invention has the following beneficial effects:

[0166] Compounds of the present invention

[0167] In this invention, the structure of carbazole compounds is designed to be suitable as the main material for the phosphorescent light-emitting layer of organic electroluminescent devices, thereby enabling the organic electroluminescent devices to have lower driving voltage, higher current efficiency, and longer lifespan. Detailed Implementation

[0168] 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.

[0169] Synthesis of intermediate P1-1 in Preparation Example 1

[0170] This preparation example provides intermediate P1-1 and its synthesis method, which is as follows:

[0171]

[0172] Under nitrogen protection, in a three-necked flask, add 80 mL of dry toluene, 3.1 g of 1-phenyl-3,5-dibromobenzene, 2.4 g of 3-phenylcarbazole, 0.0575 g of Pd(dba)2 (0.0001 mol of bis(dibenzylacetone)palladium), and a 10% (w / w) solution of tri-tert-butylphosphine in toluene (0.4 g of tri-tert-butylphosphine solution, 0.0002 mol of tri-tert-butylphosphine). The mixture was heated to 40°C for 4 hours with sodium tert-butoxide (1.44 g, 0.015 mol), then heated to 60°C for 2 hours, and then refluxed for 2 hours. The mixture was cooled to room temperature, water was added to dissolve the organic layer, and the organic layer was washed with water until neutral. The mixture was dried with magnesium sulfate, filtered to remove magnesium sulfate, concentrated to dryness, and separated by silica gel column chromatography. The mixture was eluted with a solvent of petroleum ether:ethyl acetate = 20:1 (volume ratio) to give intermediate P1-1 (1.9 g).

[0173] Mass spectrometry analysis of intermediate P1-1 showed a mass-to-charge ratio (m / z) of 473.08.

[0174] Synthesis of intermediate P2-1 in Preparation Example 2

[0175] This preparation example provides intermediate P2-1 and its synthesis method, which is as follows:

[0176]

[0177] Following the synthesis method of intermediate P1-1, intermediate P2-1 was prepared using the corresponding raw materials.

[0178] Mass spectrometry analysis of intermediate P2-1 showed a mass-to-charge ratio (m / z) of 549.11.

[0179] Synthesis of intermediate P3-1 in Preparation Example 3

[0180] This preparation example provides intermediate P3-1 and its synthesis method, which is as follows:

[0181]

[0182] Following the synthesis method of intermediate P1-1, intermediate P3-1 was prepared using the corresponding raw materials.

[0183] Mass spectrometry analysis of intermediate P3-1 showed a mass-to-charge ratio (m / z) of 549.11.

[0184] Synthesis of intermediate P4-1 in Preparation Example 4

[0185] This preparation example provides intermediate P4-1 and its synthesis method, which is as follows:

[0186]

[0187] Following the synthesis method of intermediate P1-1, intermediate P4-1 was prepared using the corresponding raw materials.

[0188] Mass spectrometry analysis of intermediate P4-1 revealed a mass-to-charge ratio (m / z) of 473.08.

[0189] Synthesis of intermediate P5-1 in Preparation Example 5

[0190] This preparation example provides intermediate P5-1 and its synthesis method, which is as follows:

[0191]

[0192] Following the synthesis method of intermediate P1-1, intermediate P5-1 was prepared using the corresponding raw materials.

[0193] Mass spectrometry analysis of intermediate P5-1 revealed a mass-to-charge ratio (m / z) of 480.12.

[0194] Synthesis of intermediate P6-1 in Preparation Example 6

[0195] This preparation example provides intermediate P6-1 and its synthesis method, which is as follows:

[0196]

[0197] Following the synthesis method of intermediate P1-1, intermediate P6-1 was prepared using the corresponding raw materials.

[0198] Mass spectrometry analysis of intermediate P6-1 revealed a mass-to-charge ratio (m / z) of 476.10.

[0199] The synthesis method of intermediate P6-0 is as follows:

[0200]

[0201] Under nitrogen protection, 70 mL of toluene, 30 mL of ethanol, and 20 mL of water were added sequentially to a three-necked flask. Then, 3.2 g of deuterated 1,3,5-tribromobenzene, 1.2 g of phenylboronic acid, 2.12 g of sodium carbonate, and 0.46 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 organic layer. The organic layer was washed with water and dried with magnesium sulfate. After removing the desiccant, the mixture was concentrated to dryness and separated by silica gel column chromatography. The eluent was petroleum ether, yielding 1.2 g of intermediate P6-0.

[0202] Mass spectrometry analysis of the obtained intermediate P6-0 revealed that the peak with the highest mass-to-charge ratio (m / z) was 314.92, with an abundance of 100%, and there were also peaks at 312.92 (abundance of approximately 50%) and 316.91 (abundance of approximately 50%).

[0203] Synthesis Example 1

[0204] This synthetic example provides compound P1 and its synthetic method, which is as follows:

[0205]

[0206] Under nitrogen protection, 70 mL of toluene, 30 mL of ethanol, and 20 mL of water were added sequentially to a three-necked flask. Then, 4.7 g of intermediate P1-1, 2.9 g of 4,6-diphenyl-1,3,5-triazine-2-boric acid, 2.12 g (0.02 mol) of sodium carbonate, and 0.23 g (0.0002 mol) of tetratetraphenylphosphine 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 organic layer. The organic layer was washed with water and dried with magnesium sulfate. After removing the desiccant, the mixture was concentrated to dryness and separated by silica gel column chromatography. The elution was performed with petroleum ether:dichloromethane:THF = 10:2:1 (volume ratio) to give 3.0 g of compound P1.

[0207] The obtained compound P1 was analyzed by mass spectrometry, and the mass-to-charge ratio (m / z) was found to be 626.25.

[0208] Synthesis Examples 2-11

[0209] Synthetic Examples 2-11 each provide a compound, the specific structures of which are shown in Table 1 below. These compounds are synthesized from raw material 1 and raw material 2, using the same synthesis method as compound P1 in Synthetic Example 1. The obtained compounds were subjected to mass spectrometry analysis, and the mass-to-charge ratios (m / z) are detailed in Table 1 below.

[0210] Table 1

[0211]

[0212]

[0213] For other compounds whose specific synthesis methods are not listed, they can be synthesized by referring to the above examples and combining them with common knowledge in the field.

[0214] The specific structures of some of the compounds used in the following application examples and comparative application examples of this invention are as follows:

[0215]

[0216]

[0217] Synthesis of compound D3:

[0218]

[0219] Following the synthesis of compound P1, compound D3 was prepared.

[0220] Mass spectrometry analysis of compound D3 revealed a mass-to-charge ratio (m / z) of 702.28.

[0221] Application Example 1

[0222] This application example provides a green organic electroluminescent device, using the compound provided by this invention as the host material of the light-emitting layer. The structure of the green organic electroluminescent device is as follows:

[0223] ITO / HT-1(80nm) / EB-1(20nm) / Main material: PGD-1[5%](35nm) / ETL-1(25nm) / LiF(0.5nm) / Al(150nm).

[0224] The fabrication method of the green organic electroluminescent device is as follows:

[0225] The material was placed inside a vacuum chamber, and the vacuum was evacuated to 1×10⁻⁶.-5 ~1×10 -6 Pa is sequentially vacuum-deposited onto a cleaned ITO substrate to fabricate OLED devices.

[0226] PGD-1[5%] refers to the doping ratio of the dye, that is, the volume ratio of the host material to the dye PGD-1 is 95:5; HT-1 is the hole transport material and EB-1 is the electron blocking layer.

[0227] The main material of the light-emitting layer of the green organic electroluminescent device provided in this application example is compound P1.

[0228] Application Example 2-7, Comparison with Application Example 1-3

[0229] Application Examples 2-7 and Comparative Application Examples 1-3 each provide a green organic electroluminescent device. The only difference from Application Example 1 is that the main material of the light-emitting layer is replaced with other compounds (see Table 3 below). The other preparation steps and conditions are the same as in Application Example 1.

[0230] Performance testing

[0231] The voltage, luminance, current efficiency, and LT95 of the organic electroluminescent devices provided above were tested. The voltage and current efficiency were measured at 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, while remaining constant, is the time. The drive voltage, current efficiency, and LT95 are relative values. Specific test results are shown in Table 2 below:

[0232] Table 2

[0233] Application Example 1 P1 1000 1 1 1 Application Example 2 P2 1000 1.03 0.96 1.08 Application Example 3 P3 1000 1.02 0.99 1.09 Application Example 4 P4 1000 1.09 1.06 0.96 Application Example 5 P5 1000 1.02 0.98 1.01 Application Example 6 P6 1000 0.98 1.11 1.02 Application Example 7 P7 1000 1.02 1.03 0.96 Comparative Application Example 1 D1 1000 1.14 0.94 0.87 Comparative Application Example 2 D2 1000 1.19 0.87 0.94 Comparative Application Example 3 D3 1000 1.12 0.79 0.81

[0234] Comparing Application Example 4 and Application Example 1, when Ar1 is selected from H, the device efficiency is improved, but the voltage and lifetime performance deteriorate.

[0235] Comparing Application Example 4 and Application Example 6, it can be seen that when the structure of the carbazole compound conforms to Formula I-1, the device voltage, efficiency, and lifetime performance are all improved.

[0236] As can be seen from the above, the present invention designs the structure of carbazole compounds to make them suitable as the main material of the phosphorescent light-emitting layer of organic electroluminescent devices, so that the organic electroluminescent devices have lower driving voltage, higher current efficiency and longer lifespan.

[0237] Compare Application Example 8-11 with Application Example 4

[0238] Application Examples 8-11 and Comparative Application Example 4 each provide a green organic electroluminescent device. The only difference between them and Application Example 1 is that the main material of the light-emitting layer has two components, and the volume ratio of the two components is 1:1 (see Table 3 below). The other preparation steps and conditions are the same as those in Application Example 1.

[0239] Performance testing

[0240] The luminance, current efficiency, and LT95 of the organic electroluminescent devices provided above were tested. The current efficiency is defined as the luminance at 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, while remaining constant, is used. Current efficiency and LT95 are relative values. Specific test results are shown in Table 3 below:

[0241] Table 3

[0242] Application Example 8 P1 H-13 1000 1 1 Application Example 9 P8 H-13 1000 0.96 1.03 Application Example 10 P9 H-13 1000 1.02 0.89 Application Example 11 P10 H-13 1000 0.92 0.81 Comparative Application Example 4 D1 H-13 1000 0.82 0.70

[0243] As can be seen from the above, this invention designs the structure of carbazole compounds to make them suitable as one of the main materials for the phosphorescent light-emitting layer of organic electroluminescent devices, thereby enabling organic electroluminescent devices to have high current efficiency and long lifespan.

[0244] In summary, by designing the structure of carbazole compounds, this invention makes them suitable as the main material for the phosphorescent light-emitting layer of organic electroluminescent devices, thereby enabling the organic electroluminescent devices to have lower driving voltage, higher current efficiency, and longer lifespan.

[0245] The applicant declares that the detailed process flow of this invention is illustrated by the above embodiments, but this invention is not limited to the above detailed process flow, that is, it does not mean that this invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

Claims

1. A carbazole compound, characterized in that, The carbazole compound is selected from any one of the following compounds: 、 、 。 2. 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 material includes the carbazole compound as described in claim 1.

3. The organic electroluminescent device according to claim 2, characterized in that, The organic thin film layer includes a light-emitting layer, and the main material of the light-emitting layer includes the carbazole compound as described in claim 1.

4. The organic electroluminescent device according to claim 3, characterized in that, The light-emitting layer is a phosphorescent light-emitting layer.

5. The organic electroluminescent device according to claim 2, characterized in that, The organic electroluminescent device is a green organic electroluminescent device.

Images