Multi-Dimensional Dynamic Fluorescence of Perovskite Driven by Light/Heat for Anti-Counterfeiting and Encryption in Five-Dimensional Codes

Abstract

Dynamic fluorescence encryption and anticounterfeiting technologies have gained widespread attention in the field of high-security information systems. However, developing dynamic multicolor fluorescence driven by multiple factors remains a significant challenge. In this study, we tuned the optical properties of CsCdCl₃ all-inorganic perovskite crystals by introducing Br^–, which induced reversible lattice distortion under UV light and relaxed to the initial state upon heating, thereby endowing the material with light-driven and heat-driven dynamic fluorescence properties. The fluorescence emission color of Br-doped CsCdCl₃ shifted from orange to white-green under UV irradiation and was restored to orange upon temperature increase. The fluorescence characteristics of the Br-doped CsCdCl₃ exhibited excellent reversibility during multiple cycles of light exposure and temperature variation tests. Based on this, we successfully implemented a multidimensional dynamic fluorescence anticounterfeiting and encryption mode driven by both light and heat. This work expands the scope of advanced anticounterfeiting and encryption strategies based on dynamic fluorescence, realizing reversible dynamic fluorescence driven by multiple factors.