US 12,133,401 B2
Light-emitting element and light-emitting device including a light-emitting layer containing quantum dots
Shinichi Handa, Sakai (JP)
Assigned to SHARP KABUSHIKI KAISHA, Sakai (JP)
Appl. No. 17/617,276
Filed by SHARP KABUSHIKI KAISHA, Sakai (JP)
PCT Filed Aug. 20, 2019, PCT No. PCT/JP2019/032410
§ 371(c)(1), (2) Date Dec. 7, 2021,
PCT Pub. No. WO2021/033257, PCT Pub. Date Feb. 25, 2021.
Prior Publication US 2022/0328778 A1, Oct. 13, 2022
Int. Cl. H10K 50/115 (2023.01); H10K 50/15 (2023.01); H10K 102/00 (2023.01)
CPC H10K 50/115 (2023.02) [H10K 50/156 (2023.02); H10K 2102/00 (2023.02)] 16 Claims
OG exemplary drawing
 
1. A light-emitting element comprising:
an anode;
a cathode;
a light-emitting layer disposed between the anode and the cathode, the light-emitting layer containing quantum dots; and
a hole transport layer disposed between the anode and the light-emitting layer, wherein the hole transport layer has
a first region adjacent to the anode, and
a second region closer to the light-emitting layer than the first region is, the second region adjoining to the light-emitting layer,
the first region has an ionization potential larger than an ionization potential of the second region and larger than an ionization potential of the light-emitting layer, and
the hole transport layer has an ionization potential decreasing gradually from near the anode in the first region to near the light-emitting layer in the second region.