Photoluminescence of Singlet/Triplet Self‐Trapped Excitons in Sb3+‐Based Metal Halides

Abstract Emerging lead‐free metal halides with low toxicity and unparalleled optoelectronic properties have attracted growing research interests, also demonstrating extensive application potentials. Among these, Sb 3+ ‐based all‐inorganic/organic–inorganic hybrid metal halides become a vital group due to the special energy level distribution along with diverse optical properties. However, there remains a gap in understanding the relationship between the crystal structure and the radiation process of involved Sb 3+ emission. Herein, the existing reports about Sb 3+ ‐based luminescent metal halides are revisited and their structure–luminescence–application relationship is explored, and it is further established that the triplet self‐trapped excitons (STEs) emission of Sb 3+ varies in different crystallographic environments and endows tunable luminescent performance. This work aims to provide constructive strategies in the further exploitation of Sb 3+ ‐based metal halides, and also guides the structural design and photoluminescence tuning of doped metal halide materials.