A tetrahydroindolocarbazole compound, a preparation method and application thereof

Abstract

The application provides a tetrahydroindolecarbazole compound and a preparation method and application thereof. The tetrahydroindolecarbazole compound has a structure as shown in formula PHI, and the intermediate is used for preparing the tetrahydroindolecarbazole compound as shown in formula PHI. The tetrahydroindolecarbazole compound provided in the application is suitable for being used as a host material of a light-emitting layer of an organic electroluminescent device, and can improve the current efficiency and the lifetime of the organic electroluminescent device.

Description

Technical Field

[0001] The invention belongs to the technical field of organic electroluminescent materials, and particularly relates to a tetrahydroindolecarbazole compound and a preparation method and application thereof. Background Art

[0002] Organic electroluminescence (EL) refers to the luminescence phenomenon in which organic materials, under the influence of an electric field, directly convert electrical energy into light energy. OLEDs utilize this principle to produce spontaneous light. They feature self-luminescence, vibrant colors, thinness, light weight, fast response, wide viewing angles, low drive voltage, resistance to harsh natural conditions, and the ability to be manufactured into flexible panels. They are gradually becoming the most advantageous technology in the next generation of flat-panel displays.

[0003] The structure of an organic electroluminescent device (OLED) specifically comprises an anode, a cathode, and an organic thin film layer between the two. To improve the efficiency and stability of organic electroluminescent devices, the organic material layer includes multiple layers with different materials, such as a hole injection layer (HIL), a hole transport layer (HTL), a light-emitting layer, an electron transport layer (ETL), an electron injection layer (EIL), an electron blocking layer, etc. In order to improve the performance of organic electroluminescent devices, various new OLED materials have also been developed. However, their various performances still need to be improved, especially in terms of current efficiency and lifespan. In order to meet people's higher requirements for OLED devices, the field urgently needs to develop more types of OLED materials with higher performance. Summary of the Invention

[0004] To address the shortcomings of the prior art, the present invention provides a tetrahydroindolecarbazole compound, a preparation method, and applications thereof. By designing the structure of the tetrahydroindolecarbazole compound, the present invention makes it suitable as a host material for the light-emitting layer of an organic electroluminescent device. The organic electroluminescent device prepared thereby exhibits high current efficiency and a long lifespan.

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

[0006] In a first aspect, the present invention provides a tetrahydroindolecarbazole compound, characterized in that the tetrahydroindolecarbazole compound has a structure as shown in formula PHI:

[0007]

[0008] Among them, Ar 901 、Ar 902 Each is independently selected from C6-C40 aryl or C6-C30 heteroaryl;

[0009] The hydrogen atoms in the tetrahydroindolecarbazole compound represented by formula PHI may be substituted by at least one of a deuterium atom, -F, -CN, a C6-C20 aryl group, a C6-C20 heteroaryl group, a C1-C20 alkyl group, and a C1-C20 alkoxy group;

[0010] The tetrahydroindole and carbazole compounds represented by formula PHI do not include

[0011] In the present invention, the structure of the tetrahydroindolecarbazole compound is designed to make it suitable as the main material of the light-emitting layer of the organic electroluminescent device, and the organic electroluminescent device prepared thereby has high current efficiency and long life.

[0012] In the present invention, Ar 901 、Ar 902 each independently selected from 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;

[0013] The hydrogen atoms in the tetrahydroindolecarbazole compound represented by formula PHI may be substituted by at least one of -D (deuterium atom, the same below), -F, -CN, C6-C20 (for example, C6, C8, C10, C12, C16 or C20, etc.) aryl group, C6-C20 (for example, C6, C8, C10, C12, C16 or C20, etc.) heteroaryl group, C1-C20 (for example, C1, C3, C4, C6, C8, C10, C12, C14, C16, C18 or C20, etc.) alkyl group, and C1-C20 (for example, C1, C3, C4, C6, C8, C10, C12, C14, C16, C18 or C20, etc.) alkoxy group.

[0014] 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.

[0015] As a preferred technical solution of the present invention, the C6-C40 aryl group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthrenyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, naphthofluorenyl, pyrenyl, peryl, spirofluorenyl, triphenylene, fluoranthenyl, hydrogenated benzanthryl, indenofluorenyl, benzoindenofluorenyl, dibenzoindenofluorenyl, naphthofluorenyl or benzonaphthofluorenyl;

[0016] Preferably, the C6-C30 heteroaryl group is selected from any one of dibenzofuranyl, dibenzothiophenyl, benzodibenzofuranyl and benzodibenzothiophenyl.

[0017] As a preferred technical solution of the present invention, the Ar 901 、Ar 902 Each is independently selected from any one of phenyl, biphenyl, 9,9-dimethylfluorenyl, naphthyl, triphenylene, fluoranthenyl, phenanthryl, dibenzofuranyl, dibenzothiophenyl, naphthodibenzofuranyl, and naphthodibenzothiophenyl.

[0018] As a preferred technical solution of the present invention, the hydrogen atoms in the tetrahydroindolecarbazole compound represented by formula PHI may be substituted by at least one of -D, -F, -CN, phenyl, naphthyl, biphenyl, fluorenyl, dibenzofuran, dibenzothiophene, methyl, ethyl, propyl, butyl, cyclohexyl, adamantyl, methoxy, ethoxy, propoxy, and butoxy.

[0019] As a preferred technical solution of the present invention, the tetrahydroindolecarbazole compound is selected from any one of the following compounds:

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026] As a preferred technical solution of the present invention, the tetrahydroindolecarbazole compound is selected from any one of the following compounds:

[0027]

[0028]

[0029] In a second aspect, the present invention provides an intermediate having a structure shown in the following formula M:

[0030]

[0031] Wherein, Ar is Ar 901 or Ar 902 ,Ar 901 、Ar 902 Has the same protection scope as the first aspect

[0032] The intermediate is used to prepare the tetrahydroindolecarbazole compound as described in the first aspect;

[0033] Preferably, the intermediate is selected from any one of the following compounds:

[0034]

[0035] In a third aspect, the present invention provides a method for preparing the tetrahydroindolecarbazole compound according to the first aspect, the preparation method comprising the following steps:

[0036]

[0037] or

[0038] Among them, Ar 901 、Ar 902 It has the same scope of protection as the first aspect;

[0039] X is selected from F, Cl, Br or I.

[0040] In a fourth aspect, the present invention provides an organic electroluminescent device, comprising an anode, a cathode, and an organic thin film layer disposed between the anode and the cathode;

[0041] The organic thin film layer includes the tetrahydroindolecarbazole compound as described in the first aspect.

[0042] Preferably, the organic thin film layer includes a light-emitting layer, and the main material of the light-emitting layer includes the tetrahydroindolecarbazole compound as described in the first aspect.

[0043] As a preferred technical solution of the present invention, the organic electroluminescent device is a phosphorescent organic electroluminescent device.

[0044] Preferably, the organic electroluminescent device is a phosphorescent blue organic electroluminescent device.

[0045] The luminescent layer of the present invention includes a luminescent layer host material and a dopant material, wherein the dopant material is also called a dye or a phosphorescent luminescent material. The luminescent layer host material can be a single compound or a mixture of two or more compounds.

[0046] 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, and a yellow phosphorescent light-emitting layer.

[0047] The volume percentage of the main material in the phosphorescent light-emitting layer is 60% to 99.9% (for example, it can be 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99.9%, etc.), preferably 70% to 99.5%, and more preferably 85% to 95%.

[0048] In the present invention, the doping material for the light-emitting layer may be a phosphorescent material, which is also called a triplet light-emitting material and refers to a substance that emits light from a triplet excited state. The specific choice of phosphorescent material in the present invention is not particularly limited, and any doping material for the light-emitting layer commonly used in the art is applicable, including but not limited to compounds having a structure as shown in Formula PD:

[0049]

[0050] wherein M is selected from Ir, Pt, Pd, Os, Ti, Zr, Hf, Eu, Tb, Tm, Cu, or Au;

[0051] Y1-Y4 are each independently selected from carbon or nitrogen;

[0052] 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;

[0053] Cy1 and Cy2 are each independently selected from phenyl, naphthyl, fluorenyl, spirofluorenyl, indenyl, pyrrolyl, thienyl, furyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, quinolyl, isoquinolyl, benzoquinolyl, quinoxalinyl, quinazolinyl, carbazolyl, benzimidazolyl, benzofuranyl, benzothiophenyl, isobenzothiophenyl, benzimidazolyl, benzoxazolyl, triazolyl, tetrazolyl, oxadiazolyl, triazinyl, dibenzofuranyl, dibenzothiophenyl, N-heterocarbazolyl, N-heterodibenzofuranyl, wherein CY1 and CY2 are optionally linked to each other via a single bond or an organic linking group;

[0054] 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;

[0055] R 91 and R 92Each is independently selected from any one of -H, -D, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazine, hydrazone, carboxylic acid group, carboxylate group, sulfonic acid group, sulfonate group, phosphoric acid group, phosphate group, -SF5, substituted or unsubstituted C1-C60 alkyl, substituted or unsubstituted C2-C60 alkenyl, substituted or unsubstituted C2-C60 alkynyl, substituted or unsubstituted C1-C60 alkoxy, substituted or unsubstituted C1-C10 heterocycloalkyl, substituted or unsubstituted C1-C10 heterocycloalkenyl, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C6-C60 aryloxy, substituted or unsubstituted C6-C60 arylthio, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, and substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group.

[0056] a1 and a2 are each independently an integer selected from 1-5;

[0057] b is an integer selected from 0 to 4;

[0058] a is selected from 1, 2 or 3;

[0059] L1 is a monovalent organic ligand, a divalent organic ligand or a trivalent organic ligand.

[0060] Preferably, the compound represented by formula PD is selected from any one of the following compounds:

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067] 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.

[0068] The hole injection layer material includes a P-type dopant. The P-type dopant coexists with the hole injection layer material in the OLED device and is capable of oxidizing the hole injection layer material, thereby acting as an electron acceptor and promoting the migration of holes from the hole injection layer toward the anode. In the present invention, the difference between the absolute value of the LUMO of the P-type dopant and the absolute value of the HOMO of the hole layer material is greater than -0.2V, preferably greater than -0.1eV, more preferably greater than 0eV, more preferably greater than 0.1eV, and even more preferably greater than 0.2eV.

[0069] The P-type dopant is present in the hole injection layer in a volume percentage of 1-10% (for example, it can be 1%, 2%, 4%, 6%, 8%, or 10%, etc.). In the present application, the type of P-type dopant is not particularly limited, and exemplary compounds can be selected from the compounds represented by D-1 to D-13 disclosed in CN113728453A or the compounds represented by HI-1 to HI-9 as described below:

[0070]

[0071]

[0072] In the present application, the hole layer material (including the hole injection layer, the hole transport layer, and the electron blocking layer) has a structure represented by formula HT-GH4:

[0073]

[0074] wherein L 41 is selected from a single bond, C6-C40 aryl, C6-C20 heteroaryl;

[0075] Ar 41 , Ar 42 are each independently selected from C6-C40 aryl, C6-C20 heteroaryl;

[0076] X is selected from CR 41 R 42 or NR 43 wherein R 41 , R 42 , R 43 is selected from any one of substituted or unsubstituted phenyl (the substituent is selected from C1-C6 alkyl, C1-C6 alkoxy, dibenzofuranyl), naphthyl, triphenylene, fluoranthene, 9,9-dimethylfluorene, biphenyl, substituted or unsubstituted dibenzofuranyl (the substituent is phenyl), substituted or unsubstituted dibenzothiophene (the substituent is phenyl), dibenzofuranyl-substituted thiophene, C1-C6 alkyl, R 41 , R 42 may be connected into a ring by a single bond.

[0077] The compound represented by formula HT-GH4 is selected from any one of the following compounds:

[0078]

[0079]

[0080]

[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) also includes a compound having a structure as shown in formula (I) or a compound having a structure as shown in formula (IA):

[0084]

[0085] Wherein, L is selected from any one of C6-C40 arylene, dibenzofuranyl or dibenzothiophenyl;

[0086] m is selected from an integer between 0 and 4, and n is selected from 0 or 1;

[0087] Ar is selected from any one of triphenylene, fluoranthenyl, dibenzofuranyl or dibenzothiophenyl;

[0088] Ar1 and Ar2 are each selected from any one of a C6-C40 aryl group, a dibenzofuranyl group, or a dibenzothiophenyl group;

[0089] 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.

[0090] R, R1, and R2 are each independently selected from any one of a C1-C20 alkyl group, a C6-C40 aryl group, a dibenzofuranyl group, and a dibenzothiophenyl group;

[0091] H in the compounds represented by formula (I) and 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, phenanthrenyl, anthracenyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, triphenylene, fluoranthenyl, pyrenyl, perylenyl, spirofluorenyl, indenofluorenyl or hydrogenated benzoanthryl.

[0092] Preferably, Ar is fluoranthene, and m+n is greater than 1;

[0093] Preferably, H in the compounds represented by formula (I) and formula (IA) can be replaced by at least one of -F, -CN, -D, C1-C3 alkyl, C1-C3 alkoxy, phenyl, biphenyl, triphenylene, and fluoranthenyl.

[0094] Preferably, each of L, Ar1, Ar2 is independently selected from at least one of phenyl, biphenyl, naphthyl, phenanthryl, anthryl, fluorenyl, benzofluorenyl, dibenzofluorenyl, triphenylenyl, fluoranthenyl, pyrenyl, perylenyl, spirofluorenyl, indenofluorenyl, or hydrogenated benzanthracenyl.

[0095] Preferably, the compound of formula (I) is selected from any one of the following compounds 1-112:

[0096]

[0097] wherein L is phenylene.

[0098] Preferably, the compound of formula (I) is selected from any one of the following compounds 1-112:

[0099]

[0100]

[0101]

[0102]

[0103] In the OLED device provided by the present application, in addition to the compound of formula HT-GH4, the compound of formula (I), and the compound of formula (IA), the hole layer material can also include conventional hole materials in the art, which are not particularly limited. Exemplary hole materials include, but are not limited to, triarylamine compounds or carbazole compounds. Preferably, the triarylamine compounds or carbazole compounds contain 3 or more N atoms, because the HOMO of the triarylamine compounds or carbazole compounds containing 3 or more N atoms is higher (smaller in absolute value), and is more suitable for use as a hole injection layer material. The triarylamine compounds or carbazole compounds containing 2 or 1 N atom can be used as a hole transport layer material. The compounds containing 1 N atom or carbazole compounds can also be used as an electron blocking layer material if they have a high LUMO.

[0104] The triarylamine compounds or carbazole compounds as the hole layer material include the following structure:

[0105]

[0106] wherein Ar 601 ~ Ar 609Each independently selected from any one of a substituted or unsubstituted C6-C40 aryl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted naphthobenzofuranyl group, a substituted or unsubstituted naphthobenzothiophenyl group, a substituted or unsubstituted dinaphthofuranyl group, and a substituted or unsubstituted dinaphthothiophenyl group;

[0107] 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;

[0108] R 701 、R 702 、R 703 is selected from C6-C40 aromatic groups, C6-C20 heteroaryl groups, C1-C6 alkyl groups, and R 701 、R 702 Can connect via one-touch.

[0109] A hole-blocking layer (HBL) can confine holes and / or excitons within the emitting layer (EL) to improve device current efficiency and lifetime. Compared to the EL material closest to the HBL interface, the HBL material has a lower HOMO (larger absolute value) and / or higher triplet energy.

[0110] The electron transport layer (ETL) may include a material capable of transporting electrons. The electron transport layer may be intrinsic (undoped) or doped, and doping may be used to enhance conductivity. In the present invention, there is no particular restriction on the ETL material, and any metal complex or organic compound may be used as long as it can transport electrons. Generally, the electron transport layer material contains the following structural fragments: at least one of a pyridine structure, a pyrimidine structure, a triazine structure, a benzimidazole structure, a benzoxazole structure, a benzothiazole structure, an N-naphthalene structure, an N-heterophthalene structure, an N-heterocarbazole structure, an N-heterodibenzofuran structure, and an N-heterodibenzothiophene structure.

[0111] In the present invention, there is no particular limitation on the electron transport layer materials, which exemplarily include but are not limited to:

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121] In the present invention, the cathode material is a metal with a low work function (e.g., alkaline earth metals, alkali metals, main group metals, or lanthanides (e.g., Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.)), a metal alloy composed of multiple metals (e.g., an alloy composed of an alkali metal or alkaline earth metal and silver, e.g., an alloy composed of magnesium and silver), or a multilayer structure. If the cathode material is a multilayer structure, in addition to the metals mentioned above, other metals with relatively high work functions, such as Ag or Al, may also be used. In this case, combinations of these metals are typically used, such as Ca / Ag, Mg / Ag, or Ba / Ag.

[0122] Alternatively, a thin intermediate layer of a material with a high dielectric constant may be introduced between the metal cathode and the organic semiconductor to form a multilayer structure. The material with a high dielectric constant may also be referred to as an electron injection material, and may be fluorides of alkali metals or alkaline earth metals, and corresponding oxides or carbonates (e.g., LiF, Li2O, BaF2, MgO, NaF, CsF, Cs2CO3, etc.) or lithium quinoline (LiQ).

[0123] Compared with the prior art, the present invention has the following beneficial effects:

[0124] In the present invention, the structure of the tetrahydroindolecarbazole compound is designed to make it suitable as the main material of the light-emitting layer of the organic electroluminescent device, and the organic electroluminescent device prepared thereby has high current efficiency and long service life. DETAILED DESCRIPTION

[0125] For the convenience of understanding the present invention, the present invention is given below with examples. It should be understood by those skilled in the art that the examples are only for the purpose of helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0126] Preparation Example 1

[0127] This preparation example provides an intermediate M1 and its synthesis method, which is as follows:

[0128]

[0129] Under nitrogen protection, 100 mL of dry toluene, 6,6,12,12-tetramethyl-5,6,7,12-tetrahydroindole[2,3-b]carbazole (3.15 g), bromobenzene (1.6 g), Pd(dba)2 (bis(dibenzylideneacetonepalladium, 0.0575 g, 0.0001 mol), a toluene solution containing 10% by mass of tri-tert-butylphosphine (0.4 g, the amount of tri-tert-butylphosphine is 0.0002 mol) and sodium tert-butoxide (1.44 g, 0.015 mol), heated to reflux, reacted for 12 h, cooled to room temperature and separated by adding water, then the organic layer was washed with water until neutral, dried over magnesium sulfate, filtered to remove magnesium sulfate, concentrated to dryness, and separated by silica gel column chromatography, eluted with a solvent of petroleum ether: ethyl acetate = 50:1 (volume ratio) to obtain 2.6 g of intermediate M1.

[0130] The intermediate M1 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 390.21.

[0131] Elemental analysis of intermediate M1 showed calculated values: C, 86.12%; H, 6.71%; N, 7.17%; found values: C, 86.13%; H, 6.68%; N, 7.16%.

[0132] Preparation Example 2-16

[0133] Preparation Examples 2-16 respectively provide an intermediate M2~M17 and a synthesis method thereof. The synthesis methods of the intermediates M2~M17 refer to the synthesis method of the intermediate M1 in Preparation Example 1, with the only difference being that bromobenzene is replaced by other brominated compounds of equal amount (see Table 1 for details), and the intermediates M2~M17 are respectively subjected to mass spectrometry detection, and the measured mass-to-charge ratios (m / z) are shown in Table 1 for details.

[0134] Table 1

[0135]

[0136]

[0137]

[0138] Synthesis Example 1

[0139] This synthesis example provides a tetrahydroindolecarbazole compound P1 and a synthesis method thereof, and the synthesis method is as follows:

[0140]

[0141] Under nitrogen protection, to a 250 mL three-necked flask were added 100 mL of dry toluene, intermediate M1 (3.9 g), bromobenzene (1.6 g), Pd(dba)2 (bis(dibenzylideneacetonepalladium, 0.0575 g, 0.0001 mol), a toluene solution containing 10% tri-tert-butylphosphine by mass (0.4 g, the amount of tri-tert-butylphosphine was 0.0002 mol) and sodium tert-butoxide (1.44 g, 0.015 mol). The mixture was heated to reflux and reacted for 12 h. After cooling to room temperature, water was added to separate the mixture. The organic layer was then washed with water until neutral, dried over magnesium sulfate, filtered to remove the magnesium sulfate, concentrated to dryness, and recrystallized from toluene to obtain 3.9 g of compound P1.

[0142] Compound P1 was detected by mass spectrometry: the mass-to-charge ratio (m / z) was measured to be 466.24.

[0143] The obtained compound P1 was subjected to nuclear magnetic resonance detection, and the data were as follows: 1 H-NMR (Bruker, Switzerland, AvanceⅡ400MHz nuclear magnetic resonance spectrometer, CDCl3), δ7.72 (m, 4H), δ7.61 (m, 2H), δ7.48 (m, 4H), δ7.38 (m, 2H), δ7.16 (m, 2H), δ6.88~6.83 (m, 4H), δ1.73 (s, 6H), δ1.69 (s, 6H).

[0144] Synthesis Example 2-43

[0145] Synthesis Examples 2-43 respectively provide a tetrahydroindole and carbazole compound P2 to P43 and a synthesis method thereof. The synthesis method refers to the synthesis method provided in Synthesis Example 1, with the only difference being that the intermediate M1 is replaced by an equal amount of another intermediate, and bromobenzene is replaced by an equal amount of another bromide (see Table 2 for details). Mass spectrometry detection was performed on the tetrahydroindole and carbazole compounds P2 to P43, and the measured mass-to-charge ratios (m / z) are shown in Table 2 for details.

[0146] Table 2

[0147]

[0148]

[0149]

[0150]

[0151]

[0152]

[0153]

[0154] The synthesis methods of the compounds not listed can refer to the above examples and the common methods in the art.

[0155] The specific structures of several materials used in the device embodiments of the present invention are as follows:

[0156]

[0157] Application Example 1

[0158] This application example provides a green organic electroluminescent device, the structure of which is as follows:

[0159] ITO / HT-1: HI-2[5%](80nm) / HT-1(30nm) / EB-1(20nm) / host material: PGD-1[8%](35nm) / ETL-1(25nm) / LiF(0.5nm) / Al(150nm).

[0160] The preparation method of the green organic electroluminescent device is as follows:

[0161] 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 to prepare OLED devices.

[0162] PGD-1 [8%] refers to the dye doping ratio, meaning the volume ratio of the host material to the dye PGD-1 is 92:8. HT-1:HI-2 [5%] refers to the ratio of the p-type dopants, meaning the volume ratio of the hole-transporting material HT-1 to the p-type dopant HI-2 is 95:5. HT-1 is a hole-transporting material; HT-1:HI-2 [5%] serves as the hole-injection layer, and EB-1 is the electron-blocking layer.

[0163] The main material of the light-emitting layer in this application example is the tetrahydroindolecarbazole compound P1.

[0164] Application Example 2-5

[0165] Application Examples 2-5 each provide a green organic electroluminescent device. The only difference from Application Example 1 is that the main material of the light-emitting layer, the tetrahydroindolecarbazole compound P1, is replaced by other tetrahydroindolecarbazole compounds (see Table 3 for details). The other preparation steps and conditions are the same as those of Application Example 1.

[0166] Comparative Application Examples 1-2

[0167] Comparative Application Example 1-2 provides a green organic electroluminescent device, which differs from Application Example 1 only in that the main material of the light-emitting layer, tetrahydroindole and carbazole compound P1, is replaced by other compounds (see Table 3 for details). The other preparation steps and conditions are the same as those of Application Example 1.

[0168] Performance Testing

[0169] The OLED-1000 multi-channel accelerated aging life and light color performance analysis system produced by Hangzhou Yuanfang was used to test the brightness, driving voltage, current efficiency and LT95 of the organic electroluminescent devices provided above. Among them, 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 50mA / cm 2 The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density is expressed in hours. The specific test results are shown in Table 3:

[0170] Table 3

[0171] Main material <![CDATA[亮度 / (cd / m 2 )]]> Current efficiency / (cd / A) LT95 / (h) Comparative Application Example 1 PHB-1 1000 38.1 322 Comparative Application Example 2 PHB-2 1000 11.4 101 Application Example 1 P1 1000 39.1 319 Application Example 2 P2 1000 50.1 368 Application Example 3 P8 1000 61.1 562 Application Example 4 P11 1000 58.2 559 Application Example 5 P40 1000 61.6 623

[0172] As can be seen from the contents of Table 3, the present invention can improve the current efficiency and service life of the organic electroluminescent device by using a tetrahydroindolecarbazole compound with a specific structure as the host material of the light-emitting layer of the green organic electroluminescent device.

[0173] Application Example 6

[0174] This application example provides a red organic electroluminescent device, the structure of which is as follows:

[0175] ITO / HT-1: HI-2[5%](80nm) / HT-1(30nm) / EB-1(20nm) / host material: PRD-1[8%](35nm) / ETL-1(25nm) / LiF(0.5nm) / Al(150nm).

[0176] The preparation method of the red organic electroluminescent device is as follows:

[0177] 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 to prepare OLED devices.

[0178] PRD-1 [8%] refers to the dye doping ratio, meaning the volume ratio of the host material to the dye PRD-1 is 92:8. HT-1:HI-2 [5%] refers to the ratio of the p-type dopant, meaning the volume ratio of the hole-transporting material HT-1 to the p-type dopant HI-2 is 95:5. HT-1 is a hole-transporting material; HT-1:HI-2 [5%] serves as the hole-injection layer, and EB-1 is an electron-blocking layer.

[0179] The main material of the light-emitting layer in this application example is the tetrahydroindolecarbazole compound P6.

[0180] Application Examples 7-8

[0181] Application Examples 7-8 each provide a red organic electroluminescent device, which differs from Application Example 6 only in that the main material of the light-emitting layer, the tetrahydroindolecarbazole compound P6, is replaced by other tetrahydroindolecarbazole compounds (see Table 4 for details). The other preparation steps and conditions are the same as those of Application Example 6.

[0182] Comparative Application Examples 3-4

[0183] Comparative Application Example 3-4 provides an organic electroluminescent device, which differs from Application Example 6 only in that the main material of the light-emitting layer, tetrahydroindole and carbazole compound P6, is replaced by other compounds (see Table 4 for details). The other preparation steps and conditions are the same as those of Application Example 6.

[0184] Performance Testing

[0185] The specific test method is as described above, and the test results are shown in Table 4:

[0186] Table 4

[0187] Main material <![CDATA[亮度 / (cd / m 2 )]]> Current efficiency / (cd / A) LT95 / (h) Comparative Application Example 3 PHB-1 1000 22.0 198 Comparative Application Example 4 PHB-2 1000 9.1 109 Application Example 6 P6 1000 26.2 222 Application Example 7 P7 1000 28.1 219 Application Example 8 P8 1000 31.2 239

[0188] As can be seen from Table 4, the present invention uses a tetrahydroindolecarbazole compound with a specific structure as the host material of the light-emitting layer of the red organic electroluminescent device, which can improve the current efficiency and service life of the organic electroluminescent device.

[0189] Application Example 9

[0190] This application example provides a blue organic electroluminescent device, the structure of which is as follows:

[0191] ITO / HT-1: HI-2[5%](80nm) / HT-1(30nm) / EB-1(20nm) / host material: PBD-1[5%](35nm) / ETL-1(25nm) / LiF(0.5nm) / Al(150nm).

[0192] The preparation method of the blue organic electroluminescent device is as follows:

[0193] The material is placed in a vacuum chamber, vacuumed to 1x10 -5 ~ 1x10 -6 Pa, and vacuum evaporated onto the cleaned ITO substrate in sequence to prepare an OLED device.

[0194] PBD-1 [5%] refers to the doping ratio of the dye, i.e. the volume ratio of the host material to the dye PBD-1 is 95:5; HT-1:HI-2 [5%] refers to the ratio of the P-type dopant, i.e. the volume ratio of the hole material HT-1 and the P-type dopant HI-2 is 95:5. HT-1 is a hole transport material; HT-1:HI-2 [5%] is used as a hole injection layer, and EB-1 is an electron blocking layer.

[0195] The host material of the light-emitting layer in this application example is a tetrahydroindolocarbazole compound P2.

[0196] Application Examples 10-12

[0197] Application Examples 10-12 each provide a blue organic electroluminescent device, which differs from Application Example 9 only in that the host material of the light-emitting layer is replaced by other tetrahydroindolocarbazole compounds (see Table 5 for details) instead of the tetrahydroindolocarbazole compound P2, and the other preparation steps and conditions are the same as those of Application Example 9.

[0198] Application Examples 13-16

[0199] Application Examples 13-16 each provide a blue organic electroluminescent device, which differs from Application Example 9 only in that the host material of the light-emitting layer is replaced by other tetrahydroindolocarbazole compounds, and the electron blocking layer material EB-1 is replaced by compound EB-2 (see Table 5 for details), and the other preparation steps and conditions are the same as those of Application Example 9.

[0200] Comparative Application Examples 5-6

[0201] Comparative Application Examples 5-6 each provide a blue organic electroluminescent device, which differs from Application Example 9 only in that the host material of the light-emitting layer is replaced by other compounds (see Table 5 for details) instead of the tetrahydroindolocarbazole compound P2, and the other preparation steps and conditions are the same as those of Application Example 9.

[0202] Performance test

[0203] The specific test method is as described above, and the test results are shown in Table 5:

[0204] Table 5

[0205]

[0206] As can be seen from Table 5, the present invention uses a tetrahydroindolecarbazole compound with a specific structure as the main material of the light-emitting layer of the blue organic electroluminescent device, which can be used in combination with different electron blocking layer materials. The organic electroluminescent device prepared has high current efficiency and long service life.

[0207] Comparison of Application Examples 1-5 and Comparative Application Example 1 shows that all of them are green light devices, using the tetrahydroindole and carbazole compounds of the present invention as green light host materials, and the current efficiency is increased from 38.1 cd / m 2 Increased to 39.1~61.6cd / m 2 , the life span can be increased from 322 to 622h.

[0208] Comparison between Application Examples 9-12 and Comparative Application Example 5 shows that all of them are blue light devices, using the tetrahydroindole and carbazole compounds of the present invention as the main blue light material, and the current efficiency is increased from 6 cd / m 2 Increased to 15.1~25.1cd / m 2 The lifespan is increased from 25 hours to 82 to 140 hours. The compounds of the present invention have a more significant improvement on the performance of blue light devices.

[0209] By comparing the data of Application Examples 9-12 and Application Examples 13-16, it can be seen that when the electron blocking layer is selected from EB-2, the prepared organic electroluminescent device has higher current efficiency and longer life.

[0210] Combining the contents of Tables 3 to 5, it can be seen that the tetrahydroindolecarbazole compounds provided by the present invention are applied to blue OLED devices, which significantly improves the current efficiency and life of the blue OLED devices. Therefore, the tetrahydroindolecarbazole compounds provided by the present invention are preferably used for preparing blue OLED devices.

[0211] Application Example 17

[0212] This application example provides a blue organic electroluminescent device, the structure of which is as follows:

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

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

[0215] The material was placed in a vacuum chamber and evacuated to 1×10 -5 ~1×10 -6 Pa was vacuum evaporated onto the cleaned ITO substrate to prepare OLED devices.

[0216] PBD-1[5%] refers to the doping ratio of the dye, that is, the volume ratio of the host material to the dye PBD-1 is 95:5; HT-1 is a hole transport material.

[0217] The main material of the light-emitting layer in this application example is the tetrahydroindolecarbazole compound P5.

[0218] Application Examples 18-30

[0219] Application Examples 18-30 each provide a blue organic electroluminescent device. The only difference from Application Example 17 is that the main material of the light-emitting layer, the tetrahydroindolecarbazole compound P5, is replaced by other tetrahydroindolecarbazole compounds (see Table 5 for details). The other preparation steps and conditions are the same as those of Application Example 17.

[0220] Application Examples 31-32

[0221] Application Examples 31-32 each provide a blue organic electroluminescent device, which differs from Application Example 17 only in that the main material of the light-emitting layer, the tetrahydroindolecarbazole compound P2, is replaced by other tetrahydroindolecarbazole compounds, and the electron transport layer material ETL-1 is replaced by other compounds (see Table 6 for details). The other preparation steps and conditions are the same as those of Application Example 17.

[0222] Performance Testing

[0223] The specific test method is as described above, and the test results are shown in Table 6:

[0224] Table 6

[0225]

[0226]

[0227] As shown in Table 6, the present invention utilizes a tetrahydroindolecarbazole compound with a specific structure as the host material for the light-emitting layer of a blue organic electroluminescent device. This compound can be used in combination with various electron transport layer materials, resulting in organic electroluminescent devices with high current efficiency and long service life. Combining this with the electron transport layer materials ETL-2 or ETL-3 further improves the device's lifespan.

[0228] In summary, the present invention designs the structure of the tetrahydroindolecarbazole compound to make it suitable as the host material of the light-emitting layer of an organic electroluminescent device, and the organic electroluminescent device prepared thereby has high current efficiency and long service life.

[0229] The applicant declares that the present invention uses the above-described embodiments to illustrate the detailed process flow of the present invention, but the present invention is not limited to the above-described detailed process flow, that is, it does not mean that the present invention must rely on the above-described detailed process flow to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacements for various raw materials in the products of the present invention, addition of auxiliary ingredients, and selection of specific methods, etc., are all within the scope of protection and disclosure of the present invention.

Claims

1. A tetrahydroindolecarbazole compound, characterized in that: The tetrahydroindolecarbazole compound has a structure as shown in formula PHI: Among them, Ar 901 、Ar 902 Each is independently selected from any one of phenyl, biphenyl, 9,9-dimethylfluorenyl, naphthyl, triphenylene, fluoranthenyl, phenanthryl, dibenzofuranyl, dibenzothiophenyl, naphthodibenzofuranyl, and naphthodibenzothiophenyl; The hydrogen atoms in the tetrahydroindolecarbazole compound represented by formula PHI are optionally substituted by at least one of a deuterium atom, -F, -CN, a C1-C20 alkyl group, and a C1-C20 alkoxy group; The tetrahydroindole and carbazole compounds represented by formula PHI do not include 2. The tetrahydroindolecarbazole compound according to claim 1, characterized in that The hydrogen atoms in the tetrahydroindolecarbazole compound represented by formula PHI are optionally substituted by at least one of a deuterium atom, -F, -CN, a methyl group, an ethyl group, a propyl group, a butyl group, a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

3. The tetrahydroindolecarbazole compound according to claim 1, characterized in that The tetrahydroindolecarbazole compound is selected from any one of the following compounds:

4. A tetrahydroindolecarbazole compound, characterized in that: The tetrahydroindolecarbazole compound is selected from any one of the following compounds:

5. An intermediate, characterized in that: The intermediate has the structure shown in the following formula M: Wherein, Ar is Ar 901 or Ar 902 ,Ar 901 、Ar 902 The definition as in claim 1.

6. The intermediate according to claim 5, characterized in that The intermediate is selected from any one of the following compounds:

7. A method for preparing a tetrahydroindolecarbazole compound according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: Among them, Ar 901 、Ar 902 The definition of as claimed in claim 1; X is selected from F, Cl, Br or I.

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 tetrahydroindolecarbazole compound according to any one of claims 1 to 4.

9. The organic electroluminescent device according to claim 8, characterized in that: The organic thin film layer includes a light-emitting layer, and a main material of the light-emitting layer includes the tetrahydroindolecarbazole compound according to any one of claims 1 to 4.

10. The organic electroluminescent device according to claim 8, characterized in that: The organic electroluminescent device is a phosphorescent organic electroluminescent device.

11. The organic electroluminescent device according to claim 10, characterized in that: The organic electroluminescent device is a phosphorescent blue organic electroluminescent device.

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