KR-102962359-B1 - Organic electroluminescent device and display device

Abstract

An organic electroluminescent device and a display device are provided. The organic electroluminescent device comprises a first electrode, a second electrode, and an organic layer located between the first electrode and the second electrode; wherein the organic layer comprises a light-emitting layer, the light-emitting layer comprises a host material, a thermally activated delayed fluorescent sensitizer, and a fluorescent dye, and the fluorescent dye is selected from a compound represented by Formula (1).

Inventors

• 리, 궈멍
• 장, 웨웨이
• 리, 멍전
• 야오, 춘량
• 류, 빈
• 쉬, 진

Assignees

• 쿤산 고-비젼녹스 옵토-일렉트로닉스 씨오., 엘티디.

Dates

Publication Date

20260511

Application Date

20210830

Priority Date

20201215

Claims (13)

1. It includes a first electrode, a second electrode, and an organic layer located between the first electrode and the second electrode; Here, the organic layer comprises a light-emitting layer, the light-emitting layer comprises a host material, a thermally activated delayed fluorescent sensitizer, and a fluorescent dye, and the fluorescent dye is selected from any one of the following compounds. ; The above host material is selected from any one of the following compounds, and , The above-mentioned thermally activated delayed fluorescent sensitizer is an organic electroluminescent device selected from any one of the following compounds: .
2. An organic electroluminescent device according to claim 1, wherein the mass of the fluorescent dye accounts for 0.1% to 10% of the total mass of the light-emitting layer.
3. A display device comprising an organic electroluminescent element according to claim 1.
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Description

Organic electroluminescent device and display device This application relates to the field of organic electroluminescent technology, and in particular to organic electroluminescent devices and display devices. Thermally activated sensitized fluorescence (TASF) means that when a thermally activated delayed fluorescence (TADF) material is used as a sensitizer, the energy of the host material is transferred to the TADF material, and then its triplet state energy is converted to a singlet state through a reverse intersystem crossing (RISC) process, and further transferred to a doped fluorescent dye to emit light. As a result, since complete energy transfer from the host to the dye molecule can be realized, existing fluorescent doped dyes can also break through the internal quantum efficiency limit of 25%. However, TASF light-emitting devices often have serious problems with dye carrier capture, high driving voltage, severe roll-off of efficiency, and relatively short lifespan. Therefore, in this field, it is urgent to develop new TASF devices that can reduce driving voltage and improve device efficiency and device lifespan. FIG. 1 is a schematic diagram of the structure of an organic electroluminescent device provided in the embodiments and comparative examples of the present application. Figure 2 is a comparison of external quantum efficiency-luminance of the devices of Example 3 and Comparative Example 2. Figure 3 is a luminance attenuation curve of the elements of Example 3 and Comparative Example 2 at a luminance of 1000 cd/ m² . To facilitate a more convenient understanding of the present application, the embodiments listed herein are as follows. It should be obvious to those skilled in the art that the above embodiments are merely for the purpose of aiding understanding of the present application and should not be construed as a specific limitation thereof. Currently, thermally activated delayed fluorescence electroluminescent devices often have serious problems with dye carrier capture, relatively high driving voltages, severe roll-off of efficiency, and relatively short lifespans. According to the inventors' research, one of the main causes of these problems is that the energy gap between the host material and the sensitizer material in the device's emissive layer is larger than the energy gap of the fluorescent material, and consequently, certain carrier capture and quenching problems exist in the fluorescent dye itself. To this end, the present application provides an organic electroluminescent device, wherein the organic electroluminescent device comprises a first electrode, a second electrode, and an organic layer located between the first electrode and the second electrode; Here, the organic layer comprises a light-emitting layer, the light-emitting layer comprises a host material, a thermally activated delayed fluorescent sensitizer, and a fluorescent dye, wherein the fluorescent dye is selected from compounds represented by Formula (1); In Equation (1), Rings A, B, C, D, and E each independently represent an aromatic ring or a heteroaromatic ring, and two adjacent rings can condense with each other to form a pentagonal or hexagonal ring containing X1 or X2 ; X1 and X2 are each independently selected from one of O, S, N, C, or Si; m is 0, 1, or 2, and n is 0, 1, or 2; R1 , R2 , R3 , R4 , and R5 each independently represent a single substitution to a maximally permissible substituent, and each independently is selected from one or at least two combinations of hydrogen, a C1 – C10 chain-type alkyl group, a C3 – C10 cycloalkyl group, a C1 – C10 alkoxy group, a halogen, a cyano group, a nitro group, a hydroxyl group, an ester group, a silyl group, an amino group, a substituted or unsubstituted C6 – C30 arylamino group, a substituted or unsubstituted C3–C30 heteroarylamino group, a substituted or unsubstituted C6 – C30 aryl group, or a substituted or unsubstituted C3 –C30 heteroaryl group, and at least one of R1 , R2 , R3 , R4 , and R5 is of formula (G); In equation (G), Z1 is selected from C or Si; RA , RB, and RC are each independently selected from one of a C1 – C10 chain-type alkyl group, a C3 – C10 cycloalkyl group, a substituted or unsubstituted C6 – C30 aryl group, or a substituted or unsubstituted C3 –C30 heteroaryl group, and at least one of RA , RB , and RC is a substituted or unsubstituted C6 – C30 aryl group or a substituted or unsubstituted C3– C30 heteroaryl group, and at least one is a C1 – C10 chain-type alkyl group or a C3 – C10 cycloalkyl group; If a substituent is present in the above group, the substituent is selected from one or a combination of at least two of a halogen, a cyano group, a carbonyl group, a C1-C12 alkyl group, a C3-C12cycloalkylgroup,aC2-C10 alkenyl group, a C1 -C6 alkoxy group or a thioalkoxy group, a C6- C30 monocyclic aryl group or a condensed aryl group, or a C3 - C30 monocyclic heteroaryl group or a condensed heteroaryl group. In equation (1), if X 1 is selecte