Defect Passivating Hole Transporting Material for Large-Area and Stable Perovskite Quantum-Dot Light-Emitting Diodes.

Li, Xiansheng; Ahangar, Hosein; Yang, Shiyu; Huang, Jing; Sheibani, Esmaeil; Kuklin, Artem V; Luo, Xin; Ghahfarokhi, Fatemeh Arami et al. · ACS Nano · 2025

basic_science · Level V

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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 <b>X13</b> and <b>X15</b>, 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 <b>X15</b>, 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<sup>2</sup>) incorporating <b>X15</b> as the HTM achieve a maximum external quantum efficiency (EQE) of 22.89%. Moreover, employing <b>X15</b> in large-area Pe-QLEDs (1 cm<sup>2</sup>) 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.