Solution-processed green and blue quantum-dot light-emitting diodes with eliminated charge leakage

• Published in: Nature photonics Vol. 16; no. 7; pp. 505 - 511
• Main Authors: Deng, Yunzhou, Peng, Feng, Lu, Yao, Zhu, Xitong, Jin, Wangxiao, Qiu, Jing, Dong, Jiawei, Hao, Yanlei, Di, Dawei, Gao, Yuan, Sun, Tulai, Zhang, Ming, Liu, Feng, Wang, Linjun, Ying, Lei, Huang, Fei, Jin, Yizheng
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.07.2022; Nature Publishing Group
• Subjects: 119/118; 639/301/1005; 639/301/1019/1020; 639/925/1130; Applied and Technical Physics; Commercialization; Current carriers; Electroluminescence; Electron affinity; Excitons; Interfaces; Leakage; Light emitting diodes; Optics; Physics; Physics and Astronomy; Polymers; Quantum dots; Quantum Physics
• ISSN: 1749-4885; 1749-4893
• DOI: 10.1038/s41566-022-00999-9

Quantum-dot light-emitting diodes (QD-LEDs) promise a new generation of efficient, low-cost, large-area and flexible electroluminescent devices. However, the inferior performance of green and blue QD-LEDs compared with their red counterpart is hindering the commercialization of QD-LEDs in display and solid-state lighting applications. Here we demonstrate green and blue QD-LEDs with ~100% conversion of the injected charge carriers into emissive excitons. The key to success is the elimination of electron leakage at the organic/inorganic interface by using hole-transport polymers with simultaneous low electron affinity and reduced energetic disorder. Our devices exhibit high external quantum efficiencies over a wide range of luminance values (peak external quantum efficiencies of 28.7% for green and 21.9% for blue) and excellent stability (extrapolated T 95 lifetime is 580,000 h for green and 4,400 h for blue QD-LEDs). We expect our work to provide a general strategy for eliminating charge leakage in solution-processed LEDs featuring organic/inorganic interfaces. A new strategy to reduce charge leakage in quantum-dot light-emitting diodes enables high external quantum efficiencies of 28.7% and 21.9% and excellent T 95 lifetimes of 580,000 h and 4,400 h for green and blue devices, respectively.