Solution-processed quantum-dot light-emitting diodes combining ultrahigh operational stability, shelf stability, and luminance
Zi Ye, Mengyu Chen, Xingtong Chen, Wenchen Ma, Xiaojuan Sun, Longjia Wu, Xiongfeng Lin, Yu Chen, Song Chen
Abstract
Abstract The shelf-stability issue, originating from the ZnO-induced positive aging effect, poses a significant challenge to industrializing the display technology based on solution-processed quantum-dot light-emitting diodes (QLEDs). Currently, none of the proposed solutions can simultaneously inhibit exciton quenching caused by the ZnO-based electron-transporting layer (ETL) and retain other advantages of ZnO. Here in this work, we propose a bilayer design of ETL in which a buffer layer assembled of SnO 2 nanoparticles (NPs) suppresses the QD-ETL exciton quenching and tunes charge balance while ZnO NPs provide high electron conductivity. As a result, the bottom-emitting QLED combining capped ZnO and SnO 2 buffer exhibit a maximum luminance over 100,000 cd m −2 and a T 95 operational lifetime averaging 6200 h at 1000 cd m −2 on the premise of entirely inhibiting positive aging.