Stable and efficient pure blue quantum-dot LEDs enabled by inserting an anti-oxidation layer
Wenjing Zhang, Bo Li, Chun Chang, Fei Chen, Qin Zhang, Qingli Lin, Lei Wang, Jinhang Yan, Fangfang Wang, Yihua Chong, Zuliang Du, Fengjia Fan, Huaibin Shen
Abstract
Abstract The efficiency and stability of red and green quantum-dot light-emitting diodes have already met the requirements for commercialization in displays. However, the poor stability of the blue ones, particularly pure blue color, is hindering the commercialization of full-color quantum-dot light-emitting diode technology. Severe hole accumulation at the blue quantum-dot/hole-transport layer interface makes the hole-transport layer prone to oxidation, limiting the device operational lifetime. Here, we propose inserting an anti-oxidation layer (poly(p-phenylene benzobisoxazole)) between this interface to take in some holes from the hole-transport layer, which mitigates the oxidation-induced device degradation, enabling a T 50 (time for the luminance decreasing by 50%) of more than 41,000 h with an initial brightness of 100 cd m −2 in pure blue devices. Meanwhile, the inserted transition layer facilitates hole injection and helps reduce electron leakage, leading to a peak external quantum efficiency of 23%.