US 11,895,857 B2
Organic light emitting element
Bora Lee, Hwaseong-si (KR); and Hyomin Ko, Suwon-si (KR)
Assigned to SAMSUNG DISPLAY CO., LTD., Yongin-si (KR)
Filed by Samsung Display Co., Ltd., Yongin-si (KR)
Filed on Mar. 25, 2021, as Appl. No. 17/212,529.
Claims priority of application No. 10-2020-0090885 (KR), filed on Jul. 22, 2020.
Prior Publication US 2022/0029122 A1, Jan. 27, 2022
Int. Cl. H10K 50/15 (2023.01); H10K 85/60 (2023.01); H10K 50/11 (2023.01); H10K 50/16 (2023.01); H10K 50/18 (2023.01)
CPC H10K 50/156 (2023.02) [H10K 85/624 (2023.02); H10K 85/633 (2023.02); H10K 85/6572 (2023.02); H10K 50/11 (2023.02); H10K 50/16 (2023.02); H10K 50/18 (2023.02)] 20 Claims
OG exemplary drawing
 
1. An organic light emitting element comprising:
a first electrode;
a hole transport region disposed on the first electrode;
an emission layer disposed on the hole transport region;
an electron transport region disposed on the emission layer, the electron transport region including an electron transport layer; and
a second electrode disposed on the electron transport region, wherein
the hole transport region comprises:
a first hole transport layer having a first refractive index;
a second hole transport layer disposed above the first hole transport layer, the second hole transport layer having a second refractive index less than the first refractive index; and
a third hole transport layer disposed below the first hole transport layer, the third hole transport layer having a third refractive index less than the first refractive index,
a difference between the first refractive index and the second refractive index is in a range of about 0.1 to about 1.0, and
a difference between the first refractive index and the third refractive index is in a range of about 0.1 to about 1.0.