Mechanoluminescence from Lead‐Free Perovskites Cs2HfCl6: Te4+

Abstract Mechanoluminescence (ML) has always attracted much attention due to the broad prospects in various fields. However, the types of ML materials are still limited. Here, the traps are introduced by means of X‐ray irradiation, and finally a high brightness ML visible to the naked eye during daytime and a 20 s ML afterglow is obtained in Cs 2 HfCl 6 : Te 4+ Inorganic Lead‐free halide perovskites (ILFHPs). This work will promote the further development of ML and provide a way of thinking for the exploration of new materials.