Perspective on Metal Halides with Self‐Trapped Exciton toward White Light‐Emitting Diodes

Metal halides with self‐trapped exciton (STE‐MHs) featuring broadband emission have manifested great potential in white light‐emitting diodes (WLEDs) with encouraging progress proceeding at an exhilarating pace. In this Perspective article, the focus is on the key issues and challenges of STE‐MH as the single‐layered emitter in WLEDs after providing a brief introduction for STE and its working mechanism of the relevant white‐light emission. Possible approaches and future research directions for efficient STE‐MH‐based WLEDs are also put forward, aiming at promoting their application in the next‐generation high‐quality solid‐state lighting sources. The key issues and challenges of metal halides with self‐trapped exciton as the single‐layered emitter in white light‐emitting diodes (WLEDs) are discussed thoroughly. These mainly include poor charge mobility and injection, limited understanding of the inner mechanism, nonradiative loss, and photoluminescence quantum yield. Among them, the charge mobility and charge injection are the greatest obstructions in constructing WLEDs.