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CN-122010955-A - Indole (3, 2, 1-JK) carbazole derivative and organic electroluminescent device thereof

CN122010955ACN 122010955 ACN122010955 ACN 122010955ACN-122010955-A

Abstract

The invention discloses an indole (3, 2, 1-JK) carbazole derivative and an organic electroluminescent device thereof, belonging to the technical field of organic luminescent materials and semiconductors, wherein the indole (3, 2, 1-JK) carbazole derivative takes indole (3, 2, 1-JK) carbazole as a donor group, the aromatic condensed ring is pi-bridge connected to the receptor group, and the steric TADF facing the receptor unit is designed, and the compound combines the characteristics of indole and carbazole, and has excellent hole transport performance, high HOMO energy level and good thermal stability. In addition, the compound is used as a luminescent layer material, has the advantages of low starting voltage, high luminous efficiency, high brightness and the like, and is suitable for preparing OLED devices with high color purity. The high-stability Organic Light Emitting Diode (OLED) has good thermal stability and film forming property, so that the OLED has good application prospect in rigid and flexible OLED devices, and has the advantages of saving cost, improving processing precision and the like. The material has wide development potential in future display technology.

Inventors

  • REN YINGGE
  • LI YU
  • Guo Suilin
  • GUO HONGMEI
  • MENG BEIBEI

Assignees

  • 西安欧得光电材料有限公司

Dates

Publication Date
20260512
Application Date
20260324

Claims (10)

  1. 1. The indole (3, 2, 1-JK) carbazole derivative is characterized in that the structural formula of the indole (3, 2, 1-JK) carbazole derivative is shown as a general formula 1: wherein " "Is a carbon chain containing 2-3 carbon atoms, Respectively connected with Ar2 in' "At both ends, ar1 is selected from substituted or unsubstituted aryl of C 6 ~C 30 , ar2 is selected from substituted or unsubstituted heteroaryl of C 6 ~C 30 , R 1 and R 2 are independently selected from H, D, or straight chain alkyl, alkoxy having 1 to 10C atoms, or branched or cyclic alkyl, alkoxy, or silyl having 3 to 10C atoms.
  2. 2. The indole (3, 2, 1-JK) carbazole derivative according to claim 1, wherein Ar1 is one of the following groups Y1 to Y6: wherein " "Means Ar1 and the main structure Represents a bondable site to Ar2, and Y2, Y3, Y5 and Y6 are respectively bonded to Ar1 through one bonding site, wherein R 3 and R 4 are respectively and independently hydrogen and substituted or unsubstituted C 1 ~C 10 alkyl.
  3. 3. An indole (3, 2, 1-JK) carbazole derivative according to claim 1, wherein R 1 and R 2 are each independently selected from hydrogen, methyl or tert-butyl.
  4. 4. The indole (3, 2, 1-JK) carbazole derivative according to claim 1, wherein Ar2 is one of the following groups G1 to G15: Wherein, is the bonding site of Ar2 and Ar1, wherein, R 5 and R 6 are respectively and independently selected from hydrogen, cyano and trifluoromethyl.
  5. 5. The indole (3, 2, 1-JK) carbazole derivative according to claim 1, wherein the indole (3, 2, 1-JK) carbazole derivative is selected from one of the following compounds 1 to 211: 。
  6. 6. An organic electroluminescent device is characterized by comprising a cathode, an anode and an organic layer positioned between the cathode and the anode, wherein the organic layer comprises a hole injection layer, a hole transport layer, an electron blocking layer, a luminescent layer, a hole blocking layer, an electron transport layer and an electron injection layer which are sequentially stacked, the components of the luminescent layer comprise a host luminescent material and a guest luminescent material, the host luminescent material comprises a first luminescent body and a second luminescent body, and the second luminescent body material is the indole (3, 2, 1-JK) carbazole derivative according to any one of claims 1-5.
  7. 7. The organic electroluminescent device according to claim 6, wherein the mass ratio of the first light-emitting host to the second light-emitting host to the guest light-emitting material in the light-emitting layer is (30-70): (0.5-5).
  8. 8. The device of claim 6, wherein the first light-emitting host material in the light-emitting layer is ; The guest luminescent material is preferably 。
  9. 9. An organic electroluminescent device as claimed in claim 6, wherein, The hole injection layer is ; The hole transport layer is HT-1 or HT-2, and the structural formula is as follows: ; the electron blocking layer is EB-1 or EB-2, and the structural formula is as follows: ; the hole blocking layer is HB-1 or HB-2, and the structural formula is: ; the electron transport layer is ET-1 or ET-2, and the structural formula is: ; The material of the electron injection layer is LiF.
  10. 10. The organic electroluminescent device according to claim 6, wherein the anode is one or more of indium tin oxide, indium zinc oxide, tin dioxide, and zinc oxide, and the cathode is magnesium, silver, aluminum-lithium alloy, calcium, magnesium-indium alloy, or magnesium-aluminum alloy.

Description

Indole (3, 2, 1-JK) carbazole derivative and organic electroluminescent device thereof Technical Field The invention belongs to the technical field of organic luminescent materials and semiconductors, and relates to an indole (3, 2, 1-JK) carbazole derivative and an organic electroluminescent device thereof. Background Organic electroluminescent devices (OLEDs) are regarded as a central development direction of next-generation solid-state lighting and full-color display technologies due to their self-luminescence, high contrast, wide viewing angle, flexibility, and the like. The luminescence mechanism is mainly based on the electroluminescent principle, electrons injected from a cathode and holes injected from an anode are combined in an organic functional layer to form excitons under the drive of an external electric field, the energy of the excitons is transferred to luminescent material molecules to enable the luminescent material molecules to transit from a ground state to an excited state, and photons are released when the excited state molecules return to the ground state through radiation transition, so that luminescence is realized. While the performance (e.g., efficiency, lifetime) of OLED devices has been significantly improved by optimizing the luminescent material system, further improvements in luminous efficiency remain a central challenge of current research. While conventional fluorescent materials can only utilize 25% of singlet excitons, phosphorescent materials can achieve 100% of internal quantum efficiency by triplet excitons, but rely on noble metal (e.g., iridium, platinum) complexes, which are costly and have insufficient blue light material stability. In recent years, thermally activated delayed fluorescence materials (TADF) have become a research hotspot because they theoretically allow 100% exciton utilization without the need for noble metals. However, the conventional TADF materials still have the problems of 1. Efficiency roll-off due to exciton annihilation at high current density, 2. Color purity deficiency due to the strong charge transfer characteristic of the donor-acceptor (D-A) to widen the emission spectrum, and 3. Molecular stacking defect due to pi-pi stacking to induce concentration quenching to reduce the film luminous efficiency. In order to break through the limitations, the sterically hindered Thermal Activation Delayed Fluorescence (TADF) material has the remarkable advantages that firstly, exciton quenching is effectively inhibited, the steric effect can reduce the intermolecular aggregation degree so as to weaken the non-radiative transition process, secondly, the accurate regulation of energy level is realized, smaller singlet-triplet energy level difference can be constructed through a space separation strategy of a donor (D) -acceptor (A) unit, corresponding delta E ST is smaller than 0.05 eV, thirdly, color purity is remarkably improved, and a rigid molecular skeleton can effectively inhibit spectrum broadening phenomenon, in particular to full width half maximum FWHM is smaller than 50 nm. However, the currently reported sterically hindered TADF materials still have key problems of complex synthesis route, unbalanced carrier transmission performance, shorter service life of blue light devices and the like. Disclosure of Invention The invention aims to overcome the defects of the prior art, and provides an indole (3, 2, 1-JK) carbazole derivative and an organic electroluminescent device thereof, so as to solve the key problems of unbalanced carrier transmission performance, shorter service life of a blue light device and the like of a TADF material in the prior art, and improve the luminous efficiency and the service life of the electroluminescent device. In order to achieve the purpose, the invention is realized by adopting the following technical scheme: An indole (3, 2, 1-JK) carbazole derivative is shown in a general formula 1: wherein " "Is a carbon chain containing 2-3 carbon atoms,Respectively connected with Ar2 in'"At both ends, ar1 is selected from substituted or unsubstituted aryl of C 6~C30, ar2 is selected from substituted or unsubstituted heteroaryl of C 6~C30, R 1 and R 2 are independently selected from H, D, or straight chain alkyl, alkoxy having 1 to 10C atoms, or branched or cyclic alkyl, alkoxy, or silyl having 3 to 10C atoms. The invention further improves that: Preferably, ar1 is one of the following groups Y1 to Y6: wherein " "Means Ar1 and the main structureRepresents a bondable site to Ar2, and Y2, Y3, Y5 and Y6 are respectively bonded to Ar1 through one bonding site, wherein R 3 and R 4 are respectively and independently hydrogen and substituted or unsubstituted C 1~C10 alkyl. Preferably, R 1 and R 2 are each independently selected from hydrogen, methyl or tert-butyl. Preferably, ar2 is one of the following groups G1 to G15: Wherein, is the bonding site of Ar2 and Ar1, wherein, R 5 and R 6 are respectively and independently selected