Balancing Charge Injection via a Tailor-Made Electron-Transporting Material for High Performance Blue Perovskite QLEDs

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 cm2·V–1·s–1, which is almost 20 times higher than the commonly used ETM-TPBi (1.1 × 10–5 cm2·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 Vturn-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.