US 12,295,198 B2
Organic electroluminescent device and display apparatus
Xiaojin Zhang, Beijing (CN); Huiyun Yang, Beijing (CN); Yong Wu, Beijing (CN); and Dan Wang, Beijing (CN)
Assigned to BOE Technology Group Co., Ltd., Beijing (CN)
Appl. No. 17/635,705
Filed by BOE Technology Group Co., Ltd., Beijing (CN)
PCT Filed Apr. 16, 2021, PCT No. PCT/CN2021/087868
§ 371(c)(1), (2) Date Feb. 16, 2022,
PCT Pub. No. WO2022/217600, PCT Pub. Date Oct. 20, 2022.
Prior Publication US 2023/0345752 A1, Oct. 26, 2023
Int. Cl. H01L 51/50 (2006.01); H10K 50/12 (2023.01); H10K 85/30 (2023.01); H10K 85/60 (2023.01); H10K 101/00 (2023.01); H10K 101/25 (2023.01); H10K 101/30 (2023.01); H10K 102/00 (2023.01)
CPC H10K 50/121 (2023.02) [H10K 85/311 (2023.02); H10K 85/6572 (2023.02); H10K 2101/25 (2023.02); H10K 2101/30 (2023.02); H10K 2101/90 (2023.02); H10K 2102/351 (2023.02)] 20 Claims
OG exemplary drawing
 
1. An organic electroluminescent device, comprising an anode, a cathode, an emitting layer arranged between the anode and the cathode, and an assistant luminescent layer located on one side, facing the anode, of the emitting layer, wherein
the assistant luminescent layer comprises a first host material and a first fluorescent guest material;
the emitting layer comprises a second host material, a TADF material, and a second fluorescent guest material; and
the first host material and the first fluorescent guest material satisfy:
S1(B)−T1(B)>0.2 eV;
S1(B)>S1(C);
T1(B)>T1(C);
∥HOMO(B)−LUMO(C)|−S1(C)|≤0.2 eV, wherein
the lowest singlet state energy of the first host material is S1(B), and the lowest triplet state energy is T1(B);
the lowest singlet state energy of the first fluorescent guest material is S1(C), and the lowest triplet state energy is T1(C); and
the highest occupied molecular orbital energy level of the first host material is HOMO (B); and the lowest occupied molecular orbital energy level of the first fluorescent guest material is LUMO (C).