Alkalis-doping of mixed tin-lead perovskites for efficient near-infrared light-emitting diodes

• 作者: Huanqin Yu Wenjing Chen Zhibin Fang Liming Ding Bingqiang Cao Zhengguo Xiao
• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2022,（1）
• 所属期刊栏目: Physical Sciences
• 页码范围: 54-60
• 页数: 7页
• 语种: 英文

摘要

Substitution of lead (Pb) with tin (Sn) is a very important way to reduce the bandgap of metal halide per-ovskite for applications in solar cells,and near infrared (NIR) light-emitting diodes (LEDs),etc.However,mixed Pb/Sn perovskite becomes very disordered with high trap density when the Sn molar ratio is less than 20％.This limits the applications of mixed Pb/Sn perovskites in optoelectronic devices such as wave-length tunable NIR perovskite LEDs (PeLEDs).In this work,we demonstrate that alkali cations doping can release the microstrain and passivate the traps in mixed Pb/Sn perovskites with Sn molar ratios of less than 20％,leading to higher carrier lifetime and photoluminescence quantum yield (PLQY).The external quantum efficiency (EQE) of Sn0.2Pb0.8-based NIR PeLEDs is dramatically enhanced from 0.1％ to a record value of 9.6％ (emission wavelength:868 nm).This work provides a way of making high quality mixed Pb/Sn optoelectronic devices with small Sn molar ratios.