US 12,408,506 B2
Organic light emitting device and display apparatus
Guanyin Wen, Beijing (CN); Yansong Li, Beijing (CN); and Xiaobo Du, Beijing (CN)
Assigned to BOE Technology Group Co., Ltd., Beijing (CN)
Appl. No. 17/608,749
Filed by BOE Technology Group Co., Ltd., Beijing (CN)
PCT Filed Jan. 22, 2021, PCT No. PCT/CN2021/073306
§ 371(c)(1), (2) Date Nov. 3, 2021,
PCT Pub. No. WO2022/155893, PCT Pub. Date Jul. 28, 2022.
Prior Publication US 2023/0255045 A1, Aug. 10, 2023
Int. Cl. H10K 50/11 (2023.01); H10K 50/12 (2023.01); H10K 50/13 (2023.01); H10K 50/18 (2023.01); H10K 59/12 (2023.01); H10K 101/10 (2023.01); H10K 101/40 (2023.01); H10K 102/00 (2023.01)
CPC H10K 50/13 (2023.02) [H10K 50/121 (2023.02); H10K 50/181 (2023.02); H10K 59/12 (2023.02); H10K 2101/10 (2023.02); H10K 2101/40 (2023.02); H10K 2102/351 (2023.02)] 16 Claims
OG exemplary drawing
 
1. An organic light emitting device, comprising: a first electrode, a second electrode, and a first emitting layer and a second emitting layer that are disposed between the first electrode and the second electrode, wherein the first emitting layer is located on a side of the second emitting layer close to the first electrode; and an electron block layer is disposed between the first emitting layer and the first electrode;
the first emitting layer comprises a first host material and a first dopant material, the second emitting layer comprises a second host material and a second dopant material, and the first host material is different from the second host material;
the electron block layer, the first emitting layer and the second emitting layer satisfy:
|HOMOEBL|<|HOMOEML1|<|HOMOEML2|,
|HOMOEML1−HOMOEBL|=0.2 eV to 0.4 eV,
where HOMOEBL is a Highest Occupied Molecular Orbit (HOMO) energy level of the electron block layer, HOMOEML1 is a HOMO energy level of the first emitting layer, and HOMOEML2 is a HOMO energy level of the second emitting layer;
and, the electron block layer, the first emitting layer and the second emitting layer satisfy:
T1EBL>T1H1>T1H2,
T1D1>T1H1,
T1D2>T1H1,
T1D1=T1D2,
T1EBL>T1D1,
where T1EBL is a lowest triplet energy level of the electron block layer, T1H1 is a lowest triplet energy level of the first host material of the first emitting layer, T1H2 is a lowest triplet energy level of the second host material of the second emitting layer, and T1D1 is a lowest triplet energy level of the first dopant material of the first emitting layer, and T1D2 is a lowest triplet energy level of the second dopant material of the second emitting layer;
wherein an exciton recombination region is located in the first emitting layer and a Triplet-Triplet Annihilation (TTA) effect occurrence region is located in the second emitting layer;
wherein both the first emitting layer and the second emitting layer are blue emitting layers;
the first dopant material and the second dopant material are blue fluorescent materials;
a ratio of a thickness of the first emitting layer to that of the second emitting layer is about 0.1 to 0.6.