Defect Passivating Hole Transporting Material for Large-Area and Stable Perovskite Quantum-Dot Light-Emitting Diodes
Xiansheng Li, Hosein Ahangar, Shiyu Yang, Jing Huang, Esmaeil Sheibani, Artem V. Kuklin, Xin Luo, Fatemeh Arami Ghahfarokhi, Changting Wei, Hans Ågren, Glib Baryshnikov, Bo Xu
Abstract
Organic hole-transporting materials (HTMs) with high hole mobility and a defect passivating ability are critical for improving the performance and stability of perovskite optoelectronics, including perovskite quantum dot light-emitting diodes (Pe-QLEDs) and perovskite solar cells. In this study, we designed two small-molecule HTMs, termed X13 and X15, incorporating the methylthio group (SMe) as defect-passivating sites to enhance the interaction between HTMs and the perovskite layer for Pe-QLED applications. Our study highlights that X15, featuring SMe groups at the para-position of the carbazole unit, demonstrates a strong interaction and superior passivation effects with perovskite quantum dots. Consequently, Pe-QLEDs (0.09 cm 2 ) incorporating X15 as the HTM achieve a maximum external quantum efficiency (EQE) of 22.89%. Moreover, employing X15 in large-area Pe-QLEDs (1 cm 2 ) yields an EQE of 21.10% with uniform light emission, surpassing the PTAA-based devices (EQE ∼ 15.03%). Our finding provides crucial insights into the molecular design of defect-passivating small-molecule HTMs for perovskite light-emitting diodes and related optoelectronic devices.