CN-121426686-B - Organic electroluminescent material and organic electroluminescent device

Abstract

The invention provides an organic electroluminescent material and an organic electroluminescent device, which belong to the field of organic electroluminescent materials, wherein the organic electroluminescent material has a structure shown in a formula I, and the organic electroluminescent material has a low refractive index, is used as a luminescent auxiliary material, is applied to a thicker layer in a double-layer luminescent auxiliary material, so that light emitted from the inside of the device passes through a film layer with the low refractive index in the formula I, and is matched with the luminescent auxiliary material with the high refractive index to prepare the organic electroluminescent device, thereby better playing a role in condensing light, emitting light with a specific wavelength in the light emitted from the inside of the device, narrowing an emission spectrum, enhancing the luminous intensity of the light with the specific wavelength, reducing light loss, improving the luminous efficiency of the device, and simultaneously ensuring lower driving voltage and longer service life of the device.

Inventors

• WANG KANG
• REN WEIHUA
• ZHANG XUE
• WANG SHIKAI
• SUN XIANGNAN
• LIU GENG
• WANG YONGZHUANG
• LIU DONGSHENG

Assignees

• 吉林奥来德光电材料股份有限公司

Dates

Publication Date

20260512

Application Date

20251229

Claims (8)

1. 1. The organic electroluminescent material is characterized by having a structure shown in a formula I: ; wherein D is deuterium; n is an integer selected from 0,1,2,3,4, 5; R is selected from methyl, ethyl, propyl and tert-butyl which are substituted or unsubstituted by deuterium; L 1 is selected from a bond or phenyl; l 2 is selected from the group consisting of phenyl, methylphenyl, naphthyl, biphenyl, terphenyl, substituted or unsubstituted with deuterium; L 3 is selected from the group consisting of phenyl, methylphenyl, naphthyl, biphenyl, substituted or unsubstituted with deuterium; R 1 is selected from deuterium substituted or unsubstituted adamantyl, cyclohexyl, tert-butyl, tert-amyl; Ar 1 is independently selected from hydrogen, phenyl, naphthyl, biphenyl, adamantyl, cyclohexyl, methyl, ethyl, t-butyl, t-amyl, 9-dimethylfluorenyl, which are substituted or unsubstituted with deuterium; m is an integer selected from 1,2,3,4, 5; Ar 2 is selected from phenyl substituted or unsubstituted with deuterium.
2. 2. The organic electroluminescent material according to claim 1, wherein the organic electroluminescent material has any one of the structures of formula I-1 to formula I-12: ; l 1 is selected from the group consisting of a linkage; n is selected from 0 or 5; L 2 is selected from the group consisting of phenyl, naphthyl, biphenyl, terphenyl, substituted or unsubstituted with deuterium; L 3 is selected from the group consisting of phenyl, naphthyl, biphenyl, substituted or unsubstituted with deuterium; Ar 1 is selected from hydrogen, phenyl, naphthyl, biphenyl, 9-dimethylfluorenyl, tert-butyl, methyl, which are substituted or unsubstituted with deuterium.
3. 3. The organic electroluminescent material as claimed in claim 1, wherein, Selected from the following groups: ; ; ; Wherein the wavy line represents the attachment site of the group.
4. 4. An organic electroluminescent material, characterized in that the organic electroluminescent material is any one of the following compounds: 。
5. 5. An organic electroluminescent device, characterized in that the organic electroluminescent device comprises an anode, a cathode, and an organic layer interposed between the anode and the cathode, the organic layer comprising a light-emitting auxiliary layer comprising the organic electroluminescent material as claimed in any one of claims 1 to 4.
6. 6. The organic electroluminescent device of claim 5, wherein the light-emitting auxiliary layer comprises a plurality of light-emitting auxiliary layers.
7. 7. The organic electroluminescent device according to claim 5, wherein the organic layer comprises a hole transport layer and a light-emitting auxiliary layer, the light-emitting auxiliary layer comprising a first light-emitting auxiliary layer and a second light-emitting auxiliary layer, the first light-emitting auxiliary layer comprising the organic electroluminescent material of any one of claims 1 to 4, the first light-emitting auxiliary layer being located between the hole transport layer and the second light-emitting auxiliary layer.
8. 8. The organic electroluminescent device of claim 7, further comprising at least one of a hole injection layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

Description

Organic electroluminescent material and organic electroluminescent device Technical Field The invention belongs to the technical field of organic electroluminescent materials, and particularly relates to an organic electroluminescent material and an organic electroluminescent device. Background Organic electroluminescence is a phenomenon of converting electrical energy into light energy by using an organic substance, and OLED (organic electroluminescent device) technology has been widely and deeply applied to various fields such as smart phones, televisions, displays, and lighting by virtue of a series of remarkable advantages such as self-luminescence characteristics, high contrast, wide viewing angle, and rapid response speed. An organic light emitting element utilizing an organic light emitting phenomenon generally has a structure including an anode and a cathode and an organic layer therebetween. In order to solve the lifetime and efficiency problems, a light-emitting auxiliary layer (multi-layer hole transport layer) is generally added between the hole transport layer and the light-emitting layer. The light-emitting auxiliary layer can enable holes transferred from the anode to smoothly move to the light-emitting layer, and can block electrons transferred from the cathode so as to limit the electrons in the light-emitting layer, reduce potential barriers between the hole-transporting layer and the light-emitting layer, reduce driving voltage of the organic electroluminescent device, further increase utilization rate of the holes, and improve luminous efficiency and service life of the device. The existing materials capable of forming the light-emitting auxiliary layer with excellent device performance are few, particularly the service life and the driving voltage of the OLED are not obviously improved, the performance of the materials often needs to be subjected to a great amount of debugging and structural improvement to enable the device performance to reach an ideal state, the device performance is the result of the comprehensive effect of various performances, such as device structure, material refractive index, HOMO, LUMO, triplet state energy level, evaporation form, free radical activity, carrier balance, evaporation temperature, mobility, capacitance, color cast, testing conditions (temperature, brightness, current density) and the like, and the device is influenced. The material manufacturer can achieve the purpose of improving the performance of the organic electroluminescent device by improving part of performance indexes. At present, materials which can be used for constructing a light-emitting auxiliary layer and can endow a device with excellent performance are very limited, and particularly, the effect is not obvious in the aspects of prolonging the service life and improving the light-emitting efficiency of an OLED. Along with the continuous improvement of the requirements of panel manufacturing enterprises on the material performance, the development of high-performance organic functional materials is particularly urgent. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide an organic electroluminescent material and an organic electroluminescent device. The compound of the invention takes 9-phenyl-9 methylfluorene substituted by Ar 2 as a core (Ar 2 is selected from phenyl, naphthyl and biphenyl which are substituted by deuterium or not), and is connected with arylamine, wherein one of the arylamine side chains contains one of adamantane, cyclohexyl and C1-C6 alkyl (especially tertiary butyl and tertiary amyl), and the obtained compound of the formula I has low refractive index. The compound with low refractive index in the invention is used as a luminescence auxiliary material, and is applied to a thicker layer in a double-layer luminescence auxiliary material, so that the organic electroluminescent device prepared by matching the light emitted from the device with the luminescence auxiliary material with high refractive index through the film with low refractive index in the formula I can better play a role in condensing light, emit light with specific wavelength in the light emitted from the device, narrow an emission spectrum, enhance the luminous intensity of the light with specific wavelength, reduce light loss, improve the luminous efficiency of the device, and simultaneously ensure lower driving voltage and longer service life of the device. In order to achieve the aim of the invention, the invention adopts the following technical scheme: in one aspect, the present invention provides an organic electroluminescent material having a structure represented by formula I: wherein D is deuterium; n is an integer selected from 0,1,2,3,4, 5; R is selected from methyl, ethyl, propyl and tert-butyl which are substituted or unsubstituted by deuterium; L 1,L2 is each independently selected from the group consisting of a bond, a substituted or unsubst