Balancing Charge Injection via a Tailor-Made Electron-Transporting Material for High Performance Blue Perovskite QLEDs
Shichen Yuan, Tao Fang, Jing Huang, Jing Huang, Xiansheng Li, Changting Wei, Yihui Zhou, Yan Li, Xin Zheng, Jinhai Huang, Jinhai Huang, Jianhua Su, Glib Baryshnikov, Wallace C. H. Choy, Haibo Zeng, Bo Xu
Abstract
One of the great challenges in perovskite quantum dot light-emitting diodes (Pe-QLEDs) is the unbalanced charge injection that significantly hinders the device performance and stability. Herein, we tailor-made a high mobility electron-transporting material (ETM), named B2, to balance the carrier injection in blue Pe-QLEDs. B2 with a tailored asymmetric anthracenyl structure exhibits a promising electron mobility of 2.7 × 10 –4 cm 2 ·V –1 ·s –1, which is almost 20 times higher than the commonly used ETM- TPBi (1.1 × 10 –5 cm 2 ·V –1 ·s –1 ). Subsequently, sky blue (490 nm) Pe-QLED with B2 as the ETM presented a remarkably high external quantum efficiency (EQE) of 13.17% and a low turn-on voltage of 2.2 V, which is much better than that of the TPBi -based device (EQE of 8.31% and V turn-on of 3.2 V). In addition, B2 also demonstrated a universal application in green and deep blue Pe-QLEDs. This work provides an important guidance to rational design of high electron mobility ETMs for high-performance LEDs.