CN-116347914-B - Organic electroluminescent device and display device

CN116347914BCN 116347914 BCN116347914 BCN 116347914BCN-116347914-B

Abstract

The present disclosure relates to an organic electroluminescent device and a display apparatus. The organic electroluminescent device comprises a first electrode, a second electrode facing the first electrode, and an interlayer between the first electrode and the second electrode and comprising a light-emitting layer, wherein the interlayer comprises a hole transport layer between the first electrode and the light-emitting layer, and a light-emitting auxiliary layer between the hole transport layer and the light-emitting layer, wherein the light-emitting auxiliary layer comprises a triplet spin density distributed segment and a hole transport material with H of an alkyl part replaced by D. By introducing deuterium on the segment aggregated by triplet spin density, molecular vibration is reduced, and stability of the material is further improved, so that service life of the device is prolonged. In addition, the introduction of deuterated alkyl in the material of the light-emitting auxiliary layer reduces the voltage to a certain extent, the introduction of the alkyl also protects the original active site, reduces the aggregation degree of molecules and prolongs the service life of the device to a certain extent.

Inventors

ZHANG DONGXU
GAO RONGRONG
CHEN LEI
SUN YUQIAN

Assignees

京东方科技集团股份有限公司

Dates

Publication Date: 20260508
Application Date: 20230420

Claims (12)

1. An organic electroluminescent device comprising: The first electrode is arranged to be electrically connected to the first electrode, A second electrode facing the first electrode, and An interlayer between the first electrode and the second electrode and comprising a light emitting layer, The interlayer includes a hole transport layer between the first electrode and the light emitting layer, and a light emitting auxiliary layer between the hole transport layer and the light emitting layer, Wherein the hole transport material of the light-emitting auxiliary layer comprises a compound of formula I: (I) Wherein, the One of Ar1 to Ar4 is The remaining three of Ar1 through Ar4 are each independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, and at least one is other than H; one of Ar5 to Ar8 is The remaining three of Ar5 through Ar8 are each independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, and at least one is other than H; L1 and L2 are each independently selected from a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroarylene group having 1 to 20 carbon atoms, a substituted or unsubstituted heterocyclylene group having 3 to 20 ring atoms, a substituted or unsubstituted aralkylene group having 7 to 30 carbon atoms, a substituted or unsubstituted alkyleneoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aralkylene group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilylene group having 3 to 20 carbon atoms, a substituted or unsubstituted arylene silyl group having 6 to 20 carbon atoms, a substituted or unsubstituted arylene group having 0 to 20 carbon atoms, and combinations thereof; At least one of R1 to R4 is selected from the following groups: 、、 Each of the others is independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carboxyl, ester, cyano, isocyano, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof; R7, R8 and R9 represent one or more substituents each independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0to 20 carbon atoms, acyl, carboxyl, ester, cyano, mercapto, sulfonyl and combinations thereof; x, Y are each independently a direct bond, CR5R6, NR6, O or S, provided that X, Y is not both a direct bond; R5 and R6 are each independently at each occurrence selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carboxyl, ester, cyano, isocyano, mercapto, sulfinyl, phosphono, and combinations thereof, Wherein the segments of the triplet spin density profile in the structure of formula I and the H of the alkyl moiety are all substituted by D.
2. The organic electroluminescent device of claim 1, wherein in formula I, L1 and L2 are direct bonds.
3. The organic electroluminescent device as claimed in claim 1, wherein in formula I, ar1 to Ar8 are other than And One of the remaining six is a perdeuterated alkyl group having 1-10 carbon atoms and the others are each independently selected from hydrogen and deuterium.
4. The organic electroluminescent device of claim 1, wherein one of X, Y is a direct bond and the other is O or S.
5. The organic electroluminescent device of claim 1, wherein one or two of R1 to R4 are selected from the group consisting of: 、、 the remainder each being independently selected from the group consisting of hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1-10 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, and combinations thereof; r7, R8 and R9 represent one or more substituents each independently selected from the group consisting of hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, and combinations thereof.
6. The organic electroluminescent device as claimed in claim 1, wherein, One or two of R1 to R4 are selected from 、、、 The remainder being selected from phenyl, biphenyl, pentadeuterated phenyl.
7. The organic electroluminescent device as claimed in any one of claims 1 to 6, wherein the compound of formula I is selected from structures represented by the following formula I-1: (I-1) Wherein, the One of Ar1 to Ar4 is The remaining three of Ar1 through Ar4 are each independently selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1-10 carbon atoms, and at least one is other than H; one of Ar5 to Ar8 is The remaining three of Ar5 through Ar8 are each independently selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1-10 carbon atoms, and at least one is other than H; R1 to R4 are as defined in the appended claims; x is O or S.
8. The organic electroluminescent device of claim 1, wherein the compound of formula I is selected from the following structures:
9. the organic electroluminescent device of claim 1, wherein the light-emitting layer comprises a dopant comprising a structure represented by formula II: (II) wherein, represent and link with metal M here, metal M is Ir or Pt; Each of A 1 and A 2 is independently selected from aryl groups having 5 to 24 ring carbon atoms, or heteroaryl groups having 5 to 24 ring atoms; Y4 is C, Y1 is N, and Y2 and Y3 are each independently selected from C and N; R 10 and R 11 each independently represent 1 to 2 substituents each independently selected from hydrogen, alkyl groups having 1 to 20 carbon atoms, each of which is substituted with deuterium, or One R 10 and one R 11 adjacent to a 1 and a 2 are joined together to form an alkylene group having 1 to 4 carbon atoms in which hydrogen is substituted entirely by deuterium.
10. The organic electroluminescent device of claim 1, wherein the light-emitting layer comprises a dopant selected from the group consisting of compounds represented by formula II-1: (II-1) Wherein M is Ir or Pt; R 101 、R 112 and R 121 are each independently selected from hydrogen and alkyl groups having 1 to 10 carbon atoms, the hydrogen being all substituted by deuterium; R 102 and R 111 are each independently selected from hydrogen and alkyl having 1 to 10 carbon atoms, all of which are substituted with deuterium, or R 102 and R 111 are taken together to form alkylene having 1 to 4 carbon atoms, all of which are substituted with deuterium; R 131 and R 132 are each independently selected from hydrogen and alkyl having 1 to 10 carbon atoms, all of which are replaced by deuterium, or R 131 and R 132 together with the benzene ring to which they are attached form Wherein X 2 is O or S, X 3 is C or N, R 141 is selected from hydrogen and alkyl groups having 1 to 10 carbon atoms, the hydrogen being all substituted by deuterium, Wherein at least one of R 101 、R 112 、R 121 and R 141 is not hydrogen.
11. The organic electroluminescent device of claim 1, wherein the light emitting layer comprises a dopant selected from the group consisting of:
12. A display device comprising the organic electroluminescent device according to any one of claims 1 to 11.

Description

Organic electroluminescent device and display device Technical Field The disclosure belongs to the technical field of organic electroluminescent devices, and in particular relates to an organic electroluminescent device and a display device. Background In recent years, organic electroluminescent display devices (OLEDs) have been receiving more attention as a new type of flat panel display. The display device has the characteristics of active light emission, high light emission brightness, high resolution, wide viewing angle, high response speed, low energy consumption, flexibility and the like, and becomes a hot mainstream display product in the market at present. With the continuous development of products, the resolution of customers for the products is higher and the power consumption requirement value is lower. There is a need to develop devices with high efficiency, low voltage, and long lifetime. Disclosure of Invention The organic electroluminescent display device may generally include an anode, a cathode, and one or more layers selected from a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer (including host and guest doping), a hole blocking layer, an electron transport layer, an electron injection layer, and the like. A light-emitting auxiliary layer (sometimes also referred to as an electron blocking layer or Prime layer) is typically added between the hole transport layer and the light-emitting layer, whereby the hole transport layer and the light-emitting auxiliary layer together form a multi-layer hole transport layer to improve device lifetime and efficiency. The light-emitting auxiliary layer mainly plays a role of assisting the hole transport layer, can play a role of reducing potential barrier between the hole transport layer and the light-emitting layer, reduces driving voltage of the organic electroluminescent device, and further increases utilization rate of holes, so that luminous efficiency and service life of the device are improved. Phosphorescent organic electroluminescent display devices have characteristics of luminescence using triplet excitons, and longer lifetimes of triplet excitons greatly increase the possibility of exciton accumulation, resulting in serious triplet-triplet quenching (TTA) and triplet-polaron quenching (TPQ) processes, which are very unfavorable for maintaining the stability of the device. Two T1 excitons may form a Tn or Sn exciton, which are high in energy, and easily lead to degradation of the light emitting layer material. In addition, since the exciton recombination region is close to the hole transport side, it is necessary to enhance the stability of the material to improve the lifetime of the device, both in the light emitting region and in the hole transport region close to the light emitting region. The inventor finds that the bond energy between part of H atoms and the connecting part in the OLED material is low, and the triplet spin density is inevitably localized on a fixed segment of the material structure due to the existence of triplet excitons, so that the material is decomposed due to the local concentration of energy. Deuterium is taken as an isotope of hydrogen, and one more neutron can inhibit molecular vibration, reduce bond length, improve bond energy and further greatly prolong the service life of the device. The inventors have also found that for an open shell system, the Alpha electron density distribution and Beta electron density distribution are different, and the spin density can be used to examine the distribution of unpaired electrons in three dimensions (spin density = Alpha electron density-Beta electron density). In the region of the triplet spin density distribution, energy aggregation is prone to material breakdown. Therefore, by replacing H in the region with D, vibration is inhibited, bond dissociation energy is further improved, and the service life of the device can be prolonged. In some embodiments, the disclosure addresses the problem that light emitting auxiliary layer materials are susceptible to decomposition of the material due to local concentration of triplet exciton energy, and molecular vibration is reduced by introducing deuterium on the fragments aggregated by triplet spin density, thereby improving the stability of the material. In some embodiments, the present disclosure coordinates light emitting layer compounds having deuterated alkyl substitution by introducing deuterated alkyl groups at the active sites of the light emitting auxiliary layer material. The introduction of alkyl groups can reduce conjugation of materials, reduce molecular accumulation, and simultaneously narrow the spectrum to reduce the evaporation temperature. The use of deuterium substituted alkyl groups can improve efficiency and stability. The device has the advantages that the device is ensured to have high efficiency and simultaneously has higher service life integrally by matching