New lead bromide chiral perovskites with ultra-broadband white-light emission

Abstract

Herein, we present for the first time on the synthesis of two chiral perovskites with white-light emission and an achiral perovskite featuring a spectral blueshift. Moreover, the luminescence mechanism of these perovskites is investigated. The direct signals of the free excitons (FEs) and self-trapped excitons (STEs) were observed by performing time-resolved nanosecond transient absorption measurements for our perovskites. This directly verifies that the broad emission indeed originates from FE and STEs. The time-resolved transient emission curves manifest that the long-lived component is assigned to STEs transition and short-lived component is ascribed to FE transition. This study promotes the development of multifunctional applications of chiral white-light emissive perovskites.