Self-trapped exciton engineering for white-light emission in colloidal lead-free double perovskite nanocrystals

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2020,（13）
• 页码范围: 1078-1084
• 页数: 7页
• 语种: 英文

摘要

Intrinsic broadband photoluminescence (PL) of self-trapped excitons (STEs) are systematically studied in lead-free double perovskite nanocrystals (NCs).It is clarified that bandgap (direct/indirect) has important influence on the PL properties of STEs:indirect bandgap NCs exhibit strong exciton-phonon coupling which results in non-radiative STEs,while direct bandgap NCs exhibit moderate exciton-phonon coupling,inducing bright STE PL.Furthermore,by alloying K+ and Li+ ions in Cs2AgInCl6 NCs,the NCs exhibit broadband white-light emission.Charge-carrier dynamics study indicates that the efficient white-light emission originates from the further suppressed non-radiative processes of the STEs in the direct bandgap structure.This work may deepen the understanding of STEs and guide the design of high-performance lead-free perovskites.