The industrialization of quantum dot light-emitting diodes (QLEDs) requires the use of less hazardous cadmium-free quantum dots, among which ZnSe-based blue and InP-based green and red quantum dots have received considerable attention. In comparison, the development of InP-based green QLEDs is lagging behind. Here, we prepare green InP/ZnSe/ZnS quantum dots with a diameter of 8.6 nm. We then modify the InP quantum dot emitting layer by passivation with various alky l diamines and zinc halides, which decreases electron mobility and enhances hole transport. This, together with optimizing the electron transport layer, leads to green 545 nm InP QLEDs with a maximum quantum efficiency (EQE) of 16.3% and a current efficiency 57.5 cd/A. EQE approaches the theoretical limit of InP quantum dots, with an emission quantum yield of 86%.
- Department of Chemistry, National Taiwan University, 10617, Taipei, Taiwan
Wei-Chih Chao, Tzu-Hsuan Chiang, Yi-Chun Liu, Zhi-Xuan Huang, Chih-Hsing Wang & Pi-Tai Chou
- Unique Materials Co., Ltd, Taipei, Taiwan
Chia-Chun Liao, Chen-Hsien Chu & Huan-Wei Tseng
- Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, 20224, Keelung, Taiwan