Advanced Optoelectronic Properties of Sb(III) based Metal Halides: Opportunities and Challenges

Abstract Sb ³ ⁺‐activated metal halides (A _x B _m X _n, A = alkali metal ion or organic cation, B = Sb or other metal ion with a valence state of +2 to +4) have attracted great attention in recent years due to their unique electronic structure, diverse crystal structures, efficient self‐trapped exciton emission, and widely tunable broadband luminescence. Many Sb ³ ⁺‐activated metal halides can exhibit efficient and varied emission colors from blue to near‐infrared due to their varied composition, their coordination number, and local symmetry. These materials exhibit excellent optical properties, including highly efficient photoluminescence with near‐unity quantum yield, radioluminescence, afterglow, and circularly polarized luminescence. This review summarizes recent progress on Sb ³ ⁺‐based metal halides, focusing on the relationships among their local structures, electronic states, highly efficient luminescence processes, and rich applications. The potential and challenges of these materials in optoelectronic devices are addressed.