Tunable Photoluminescence of LiTaO3: Tb3+, Sm3+ For Dynamic Multimode Optical Anti‐counterfeiting

Currently, static fluorescent anti‐counterfeiting technology struggles to cope with the increasingly sophisticated counterfeiting techniques, making the dynamic multimode regulation scheme an urgent necessity. Herein, Sm3+ mono‐/co‐doped LiTaO3 (LTO) phosphors are prepared by high temperature solid state method. Under 254 nm excitation, the emission chromaticity of LTO: Tb3+, Sm3+ is modulated from green to yellow by increasing Sm3+ content due to Tb3+ → Sm3+ energy transfer. The diverging luminescence thermal stability of LTO: Tb3+ and LTO: Sm3+ is uncovered, which is governed by their distinct vacuum‐referenced binding energy (VRBE) levels and charge compensation mechanisms. Based on the time‐domain difference between the trap‐assisted afterglow of Tb3+ and the photoluminescence of Sm3+, a dynamic anti‐counterfeiting pattern that changes from green to orange over time is designed. This work provides a novel material design strategy for time‐resolved color signatures and multi‐modal dynamic optical encryption.