Indolocarbazole compound, composition and organic electroluminescent device

Abstract

The invention provides an indolocarbazole compound, a composition and an organic electroluminescent device. The indolocarbazole compound has a structure as shown in a formula I which is described in the specification. The structure of the indolocarbazole compound is designed, so that the indolocarbazole compound is suitable for being used as a main body material of a luminescent layer of the organic electroluminescent device, and the organic electroluminescent device has relatively low driving voltage, relatively high current efficiency and relatively long service life.

Description

Technical Field

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

[0002] The structure of an organic light-emitting diode (OLED) consists of an anode, a cathode, and an organic layer between them. To improve the efficiency and stability of OLEDs, 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. Electron transport materials, hole injection materials, hole transport materials, or hole blocking layers are major obstacles to the widespread practical application of OLED technology, directly limiting the device's luminous efficiency, lifespan, and operating voltage.

[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 an indole-carbazole compound, a composition, and an organic electroluminescent device. In this invention, the structure of the indole-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 an indolocarbazole compound having the structure shown in Formula I:

[0007]

[0008] Ar1, Ar2, and Ar3 are each independently selected from C6-C40 aryl or C6-C30 heteroaryl; and any two of Ar1, Ar2, and Ar3 are linked together to form a ring by a single bond.

[0009] A1, A2, and A3 are each independently selected from N or CR, and at least one is selected from N; R is selected from any one of H, C6-C20 aryl or C1-C12 alkyl;

[0010] Ar 11Groups selected from the structures shown in formulas A-1 to A-10 below, Ar 12 Groups selected from the structures shown in formulas A-1 to A-2 and A-4 to A-10, where "*" indicates the connection position:

[0011]

[0012]

[0013] Ar4, Ar5, Ar 6、 Ar7 are each independently selected from C6-C40 aryl or C6-C30 heteroaryl;

[0014] Y is selected from Si;

[0015] In compounds of formula I, each hydrogen atom can be independently substituted by at least one of deuterium (-D), -F, -CN, C6-C20 aryl, C1-C12 alkyl, or C1-C12 alkoxy.

[0016] In this invention, the structure of indolocarbazole compounds is designed to make 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.

[0017] In this invention, C6-C40 can be C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.

[0018] C6-C30 can be C6, C8, C10, C12, C16, C20, C24, C28, or C30, etc.

[0019] C6-C20 can be C6, C8, C10, C12, C16, or C20, etc.

[0020] C1 to C12 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12.

[0021] It should be noted that in this invention, "-D" represents a deuterium atom, and the same applies below.

[0022] 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.

[0023] 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 phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, triphenylene, and fluoranthyl.

[0024] As a preferred embodiment of the present invention, the C6-C30 heteroaryl group is selected from any one of carbazolyl, dibenzothiophenel, and dibenzofuranyl.

[0025] As a preferred embodiment of the present invention, the C6-C20 aryl group is selected from any one of phenyl, biphenyl, terphenyl, and naphthyl.

[0026] As a preferred embodiment of the present invention, the C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, tert-butyl, and cyclohexyl.

[0027] As a preferred embodiment of the present invention, the C1-C12 alkoxy group is selected from any one of methoxy, ethoxy, propoxy, butoxy, pentoxy, and hexoxy.

[0028] As a preferred technical solution of the present invention, the Ar1, Ar2, Ar3, Ar4, Ar5, and Ar 6、 Ar7 is independently selected from any one of phenyl, carbazolyl, biphenyl, naphthyl, triphenylene, dibenzothiophene, or dibenzofuranyl.

[0029] Preferably, Ar1, Ar2, and Ar3 are each independently selected from any one of phenyl, biphenyl, dibenzofuranyl, dibenzothiophenyl, or carbazoleyl, and more preferably any one of phenyl, naphthyl, or biphenyl.

[0030] Preferably, the Ar4, Ar5, and Ar 6、 Ar7 is independently selected from any one of phenyl, naphthyl, biphenyl, carbazolyl, dibenzofuranyl, and dibenzothiophene, with phenyl being a further preferred choice.

[0031] As a preferred technical solution of the present invention, the Ar 11 Selected from any one of the groups shown in Formula A-1 to Formula A-8;

[0032] Ar4, Ar5, Ar6, and Ar7 are selected from phenyl.

[0033] Preferably, the Ar 11 Selected from the groups shown in Formula A-3.

[0034] Preferably, the Ar 12 It is selected from any one of the groups shown in Formula A-2, Formula A-7 to Formula A-10.

[0035] As a preferred embodiment of the present invention, A1, A2, and A3 are selected from N.

[0036] Preferably, A1 is selected from CR, R is selected from H, and A2 and A3 are selected from N.

[0037] Preferably, A1 and A3 are selected from CR, R is selected from H, and A2 is selected from N.

[0038] As a preferred embodiment of the present invention, the hydrogen atoms in the indolocarbazole compounds may be independently substituted by at least one of -D, -F, -CN, phenyl, naphthyl, biphenyl, methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, or butoxy.

[0039] Preferably, the hydrogen atoms in the indolocarbazole compound can be independently substituted by at least one of -D, -F, -CN, phenyl, naphthyl, methyl, ethyl, tert-butyl, methoxy, and propoxy.

[0040] Preferably, the hydrogen atoms in the indolocarbazole compound can each be independently substituted by at least one of deuterium (-D), -F, -CN, phenyl, naphthyl, or biphenyl.

[0041] Preferably, each hydrogen atom in the compound of formula I can be independently replaced by -CN.

[0042] As a preferred embodiment of the present invention, the indolecarbazole compound has any one of the structures shown in Formula I-1 to Formula I-6:

[0043]

[0044] Among them, Ar 11 It has the same definition as above.

[0045] As a preferred embodiment of the present invention, the indolocarbazole compound is selected from any one of the following substituted or unsubstituted compounds:

[0046]

[0047]

[0048]

[0049] The substitution refers to the independent substitution of each hydrogen atom in the aforementioned indolocarbazole compounds by a deuterium atom. Preferably, the indolocarbazole compounds are selected from any one of the following compounds:

[0050]

[0051] It should be noted that the present invention does not impose any special limitations on the synthesis method of the above-mentioned indolocarbazole compounds, and commonly used synthesis methods in the art are applicable.

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

[0053] The first component includes a compound of formula I as described in the first aspect;

[0054] The second component comprises a compound having the structure shown in Formula II:

[0055]

[0056] Among them, Ar 31 Ar 32 Each is independently selected from any one of single bond, C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40, etc.) arylene or C6-C30 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, or C30, etc.) heteroarylene;

[0057] Ar 33 It is selected from any one of H, C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) aryl or C6-C30 (e.g., C6, C8, C10, C12, C16, C20, C24, C28 or C30, etc.) heteroaryl;

[0058] p1 and p2 are each independently selected from 0, 1, 2, 3 or 4;

[0059] The hydrogen atom in the compound of formula II may be substituted by at least one of the following: deuterium atom, -F, -CN, C6-C20 (e.g., C6, C8, C10, C12, C16 or C20), C1-C12 (e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12), C1-C12 (e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12), trimethylsilyl, triphenylsilyl, tetraphenylmethyl.

[0060] As a preferred embodiment of the present invention, the compound of formula II is selected from any one of the following substituted or unsubstituted compounds:

[0061]

[0062]

[0063]

[0064] The substitution refers to the fact that each hydrogen atom in the above compound can be independently replaced by a deuterium atom.

[0065] It should be noted that there are no special restrictions on the preparation methods of the above compounds in this invention, and commonly used preparation methods in the art are applicable.

[0066] 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;

[0067] The organic thin film layer material includes indolocarbazole compounds as described in the first aspect and / or compositions as described in the second aspect.

[0068] 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 indolocarbazole compounds as described in the first aspect.

[0069] Preferably, the light-emitting layer is a phosphorescent light-emitting layer.

[0070] As a preferred embodiment of the present invention, the organic electroluminescent device is a green organic electroluminescent device.

[0071] 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.

[0072] 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.

[0073] 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%.

[0074] 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.

[0075]

[0076] Wherein, M is selected from any one of Ir, Pt, Pd, Os, Ti, Zr, Hf, Eu, Tb, Tm, Cu or Au;

[0077] Y1-Y4 are each independently selected from carbon or nitrogen;

[0078] 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.

[0079] 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;

[0080] 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.

[0081] 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., 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.

[0082] a1 and a2 are each independent integers selected from 1 to 5, for example, they can be 1, 2, 3, 4 or 5;

[0083] b is an integer selected from 0 to 4, for example, it can be 0, 1, 2, 3 or 4;

[0084] a is selected from 1, 2, or 3;

[0085] L1 can be a monovalent organic ligand, a divalent organic ligand, or a trivalent organic ligand.

[0086] Preferably, the PD compound is selected from any one of the following compounds:

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094] 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.

[0095] 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 -0.2 eV, preferably greater than -0.1 eV, more preferably greater than 0 eV, more preferably greater than 0.1 eV, and more preferably greater than 0.2 eV.

[0096] 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.

[0097]

[0098] 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:

[0099]

[0100] 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, etc.) aryl, and C6-C20 (e.g., C6, C8, C10, C12, C16, or C20, etc.) heteroaryl;

[0101] Ar 41 Ar42 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;

[0102] X is selected from CR 41 R 42 Or NR 43 , where R 41 R 42 R 43 Each is independently selected from any one of 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, R 41 R 42 They can be connected into a ring using a single key.

[0103] The HT-GH4 compound is selected from any one of the following compounds:

[0104]

[0105]

[0106]

[0107]

[0108]

[0109] 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:

[0110]

[0111] 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;

[0112] 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;

[0113] Ar is selected from any one of triphenylene, fluorene anthracene, dibenzofuranyl or dibenzothiophene;

[0114] 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.);

[0115] Ar1 and Ar, Ar2 and Ar, and Ar1 and Ar2 can be independently connected or bridged by single bonds, O, S, CR1R2, NR.

[0116] 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.

[0117] 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.

[0118] Preferably, the Ar is fluoreneanthracene, where m+n>1.

[0119] 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.

[0120] 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.

[0121] Preferably, the compound of formula IB is selected from the following structures:

[0122]

[0123] Wherein, L represents phenylene;

[0124] Ar1, Ar2, and m have the same protection range as described above.

[0125] Preferably, the compound of formula IB is selected from any one of the following compounds 1-112:

[0126]

[0127]

[0128]

[0129]

[0130] 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.

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

[0132]

[0133] Among them, Ar 601 ~Ar 609 Each 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;

[0134] And Ar 601 ~Ar 609Ar 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 NR 703 bridging;

[0135] 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 groups, C6-C20 (e.g., C6, C8, C10, C12, C16, or C20, etc.) heteroaryl groups, and C1-C6 (e.g., C1, C2, C3, C4, C5, or C6) alkyl groups, and R 701 R 702 It can be connected with a single button.

[0136] 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.

[0137] 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.

[0138] In this invention, no special restrictions are placed on the electron transport layer material, which includes, but is not limited to, the following:

[0139]

[0140]

[0141]

[0142] 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.

[0143] 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).

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

[0145] In this invention, the structure of indolocarbazole compounds is designed to make 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. Detailed Implementation

[0146] 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.

[0147] Synthesis Example 1

[0148] This synthetic example provides compound P1, which is synthesized as follows:

[0149]

[0150] Under nitrogen protection in a three-necked flask, 0.01 mol of intermediate P1-1, 0.01 mol of intermediate P1-2, 50 mL of DMF, 0.012 mol of anhydrous potassium carbonate, and 1.0 g of cuprous iodide were added. The mixture was heated to 80 °C and reacted for 12 hours. After cooling, water and toluene were added to separate the layers. The organic layer was washed with water until neutral. The mixture was separated by silica gel column chromatography, eluted with petroleum ether:ethyl acetate:dichloromethane = 20:1:2 (v / v), to give compound P1 (5.7 g).

[0151] The obtained compound P1 was analyzed by mass spectrometry, and the mass-to-charge ratio (m / z) was found to be 819.28.

[0152] Synthesis Examples 2-5

[0153] Synthesis Examples 2-5 provide the following compounds and their synthesis methods in sequence. The synthesis methods are the same as those in Synthesis Example 1, except that the raw materials are replaced. The obtained compounds were subjected to mass spectrometry detection, and the mass-to-charge ratios (m / z) are shown in Table 1 below.

[0154] Table 1

[0155]

[0156]

[0157] 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.

[0158] The specific structures of some of the compounds used in the following application examples and comparative application examples of this invention are as follows:

[0159]

[0160] Application Example 1

[0161] This application example provides a green organic electroluminescent device, using the composition provided by the present invention as the host material for the light-emitting layer. The structure of the green organic electroluminescent device is as follows:

[0162] ITO / HT-1: HI-2[5%](80nm) / HT-1(30nm) / EB-2(20nm) / Main material: GD1[5%](35nm) / ETL-1(25nm) / LiF(0.5nm) / Al(150nm).

[0163] The fabrication method of the green organic electroluminescent device is as follows:

[0164] 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.

[0165] Wherein GD1[5%] refers to the doping ratio of the dye, that is, the volume ratio of the host material to the dye GD1 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 to the p-type dopant HI-2 is 95:5. HT-1 is the hole transport material; HT-1:HI-2[5%] is used as the hole injection layer, and EB-2 is the electron blocking layer.

[0166] The main materials of the light-emitting layer of the green organic electroluminescent device provided in this application example are compounds P1 and H-1, and the volume ratio of P1 to H-1 is 4:6.

[0167] Application Example 2-6

[0168] Application Examples 2-6 provide a green organic electroluminescent device, which differs from Application Example 1 only in that the main material of the light-emitting layer is replaced with other compounds, and the volume ratio of main material 1 to main material 2 in the composition is 4:6 (see Table 2 below). Other preparation steps and conditions are the same as in Application Example 1.

[0169] Comparative application examples 1-2

[0170] Comparative Application Examples 1-2 provide an organic electroluminescent device, which differs from Application Example 1 only in that the main material 1 of the light-emitting layer is different (the main material of the light-emitting layer is replaced by other compounds, and the volume ratio of main material 1 to main material 2 in the composition is 4:6 (see Table 2 below). Other preparation steps and conditions are the same as in Application Example 1.

[0172] Performance testing

[0173] The luminance, driving voltage, current efficiency, and LT95 of the organic electroluminescent devices provided above were tested. 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, while remaining constant, is given. Voltage, current efficiency, and LT95 are relative values. Specific test results are shown in Table 2 below.

[0174] Table 2

[0175] Main material 1 Main material 2 <![CDATA[Brightness / (cd / m 2 )]]> Drive voltage Current efficiency LT95 Application Example 1 P1 H-1 1000 1 1 1 Application Example 2 P2 H-1 1000 0.97 0.93 1.07 Application Example 3 P3 H-1 1000 1.02 0.98 1.11 Application Example 4 P4 H-1 1000 1.04 1.23 1.29 Application Example 5 P5 H-1 1000 0.76 1.17 1.13 Application Example 6 P1 H-2 1000 0.96 1.11 1.16 Comparative Application Example 1 D1 H-1 1000 1.09 0.86 0.71 Comparative Application Example 2 D2 H-1 1000 1.11 0.61 0.65

[0176] As can be seen from the above, by designing the structure of indolocarbazole compounds in this invention, the two N atoms in the indolocarbazole structural fragment of the compound are located in the ortho position (compared to D1), which increases the electron density of the indolocarbazole structural fragment, improves its charge transport performance and film-forming properties, and makes it suitable as the main material for the phosphorescent light-emitting layer of organic electroluminescent devices, so that the organic electroluminescent devices have lower driving voltage, higher current efficiency and longer lifetime.

[0177] As can be seen from application example 4, Ar in indolocarbazole compounds 11When the group is selected from the group shown in Formula A-3, the indole-carbazole compound can be used as the main material of the phosphorescent layer of organic electroluminescent device, which can further improve the current efficiency and lifespan of organic electroluminescent device.

[0178] As can be seen from Application Example 5, when some hydrogen atoms in an indolocarbazole compound are replaced by -CN, the group shown in Formula A-5 can be used as the main material for the phosphorescent layer of an organic electroluminescent device, thereby further reducing the driving voltage of the organic electroluminescent device.

[0179] A comparison of Application Example 6 and Application Example 1 shows that when the main material 2 is selected from H-2, the device performance is further improved.

[0180] 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. An indolocarbazole compound, characterized in that, The indolocarbazole compounds have the structure shown in Formula I: Ar1, Ar2, and Ar3 are each independently selected from C6-C40 aryl or C6-C30 heteroaryl; and any two of Ar1, Ar2, and Ar3 are linked together to form a ring by a single bond. A1, A2, and A3 are each independently selected from N or CR, and at least one is selected from N; R is selected from any one of H, C6-C20 aryl or C1-C12 alkyl; Ar 11 Groups selected from the structures shown in formulas A-1 to A-10 below, Ar 12 Groups selected from the structures shown in formulas A-1 to A-2 and A-4 to A-10, where "*" indicates the connection position: Ar4, Ar5, Ar 6、 Ar7 are each independently selected from C6-C40 aryl or C6-C30 heteroaryl; Y is selected from Si; In compounds of formula I, each hydrogen atom can be independently substituted by at least one of -D, -F, -CN, C6-C20 aryl, C1-C12 alkyl, or C1-C12 alkoxy.

2. The indolocarbazole compound according to claim 1, characterized in that, The C6-C40 aryl group is selected from any one or a combination of at least two of phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, triphenylene, or fluoranyl. Preferably, the C6-C30 heteroaryl group is selected from any one of carbazole, dibenzothiophene, or dibenzofuranyl; Preferably, the C6-C20 aryl group is selected from any one of phenyl, biphenyl, terphenyl, or naphthyl; Preferably, the C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, tert-butyl, or cyclohexyl; Preferably, the C1-C12 alkoxy group is selected from any one of methoxy, ethoxy, propoxy, butoxy, pentoxy, or hexoxy.

3. The indolocarbazole compound according to claim 1 or 2, characterized in that, The Ar1, Ar2, Ar3, Ar4, Ar5, Ar 6、 Ar7 is independently selected from any one of phenyl, carbazolyl, biphenyl, naphthyl, triphenylene, dibenzothiophene, or dibenzofuranyl; Preferably, Ar1, Ar2, and Ar3 are each independently selected from any one of phenyl, biphenyl, dibenzofuranyl, dibenzothiophenyl, or carbazoleyl, and more preferably any one of phenyl, naphthyl, or biphenyl. Preferably, the Ar4, Ar5, and Ar 6、 Ar7 is independently selected from any one of phenyl, naphthyl, biphenyl, carbazolyl, dibenzofuranyl, and dibenzothiophene, with phenyl being a further preferred choice; Preferably, the Ar 11 Selected from any one of the groups shown in Formula A-1 to Formula A-8; Ar4, Ar5, Ar6, and Ar7 are selected from phenyl groups; Preferably, the Ar 11 Selected from the groups shown in Formula A-3; Preferably, the Ar 12 It is selected from any one of the groups shown in Formula A-2, Formula A-7 to Formula A-10.

4. The indolocarbazole compound according to any one of claims 1-3, characterized in that, A1, A2, and A3 are selected from N; Preferably, A1 is selected from CR, R is selected from H, and A2 and A3 are selected from N; Preferably, A1 and A3 are selected from CR, R is selected from H, and A2 is selected from N; Preferably, each hydrogen atom in the indolocarbazole compound can be independently substituted by at least one of -D, -F, -CN, phenyl, naphthyl, biphenyl, methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, or butoxy. Preferably, the hydrogen atoms in the indolocarbazole compounds can each be independently substituted by at least one of -D, -F, -CN, phenyl, naphthyl, methyl, ethyl, tert-butyl, methoxy, and propoxy. Preferably, the hydrogen atoms in the indolocarbazole compound can each be independently substituted by at least one of -D, -F, -CN, phenyl, naphthyl or biphenyl; Preferably, each hydrogen atom in the compound of formula I can be independently replaced by -CN.

5. The indolocarbazole compound according to any one of claims 1-4, characterized in that, The indolocarbazole compounds have any one of the structures shown in Formulas I-1 to I-6: Among them, Ar 11 It has the same definition as claim 1.

6. The indolocarbazole compound according to any one of claims 1-5, characterized in that, The indolocarbazole compounds are selected from any one of the following substituted or unsubstituted compounds: The substitution refers to the independent replacement of each hydrogen atom in the aforementioned indolocarbazole compounds by a deuterium atom.

7. A composition, characterized in that, The composition comprises a first component and a second component; The first component includes an indolocarbazole compound as described in any one of claims 1-6; The second component comprises a compound having the structure shown in Formula II: Among them, Ar 31 Ar 32 Each is independently selected from any one of single bonds, C6-C40 arylene, or C6-C30 heteroarylene; Ar 33 Selected from any one of H, C6-C40 aryl, or C6-C30 heteroaryl; p1 and p2 are each independently selected from 0, 1, 2, 3 or 4; The hydrogen atom in the compound of formula II may be substituted by at least one of the following: deuterium atom, -F, -CN, C6-C20 aryl, C1-C12 alkyl, C1-C12 alkoxy, trimethylsilyl, triphenylsilyl, and tetraphenylmethyl.

8. The composition according to claim 7, characterized in that, The compound of formula II is selected from any one of the following substituted or unsubstituted compounds: The substitution refers to the fact that each hydrogen atom in the above compound can be independently replaced by a deuterium atom.

9. 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 indole-carbazole compounds as described in any one of claims 1-6 and / or compositions as described in claim 7 or 8.

10. The organic electroluminescent device according to claim 9, characterized in that, The organic thin film layer includes a light-emitting layer, and the main material of the light-emitting layer includes an indole-carbazole compound as described in any one of claims 1-6; Preferably, the light-emitting layer is a phosphorescent light-emitting layer; Preferably, the organic electroluminescent device is a green organic electroluminescent device.

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