Multicolor Mechanoluminescence in Sr₂Ga₂GeO₇: Pr³⁺ for Stress Sensing and Anticounterfeiting

Abstract Mechanical luminescence (ML) is the conversion of mechanical energy into light energy when a material is subjected to a force. It is challenging to develop ML materials with tunable luminescent properties by single ion doping, which have broad application prospects in the fields of stress sensing and dynamic signature anticounterfeiting. In this study, a Pr³⁺ doped Sr₂Ga₂GeO₇ tunable ML material is reported. Due to the traps resulting from unequal substitution of Pr³⁺–Sr²⁺ in [SrO₆] heptahedra, the deep/shallow traps redistribution occurs towards a multicolor ML from red to green. In addition, even after continuous friction sliding force (15 N), the ML intensities can be recovered after ultraviolet pre‐irradiation, indicating that Sr₂Ga₂GeO₇: Pr³⁺ has excellent ML emission stability. Based on thermoluminescence analysis, potential PersL and ML mechanisms are further elaborated by a lattice engineering (trap regulation) strategy. In all, the development of single‐ion doped multicolor ML materials may have crucial research value and show a variety of potential applications in the fields of anticounterfeiting and information encryption.