Optical anti-counterfeiting and encryption have become a hotspot in information security. However, the advanced optical anti-counterfeiting technology still suffers from low security by single-luminescent mode. Herein, we present a novel multi-mode anti-counterfeiting strategy based on K3LuSi2O7: Tb3+/Bi3+ (KLSO: Tb3+/Bi3+) phosphors for the first time. KLSO not only provides various lattice sites for Bi3+ ions occupying to achieve tunable luminescence but can also be non-equivalently substituted by Tb3+ ions to produce persistent or thermo-luminescence. Furthermore, in the pattern "8888" constructed by the mixture of polyacrylic acid (PAA) with KLSO: Tb3+/Bi3+ phosphors, we selectively trigger the three luminescent modes of Bi3+ and Tb3+ ions to realize the design of differential display in the fields of thermal response, time resolution, and luminescence color for optical anti-counterfeiting. The differentiated display can only be presented under specific multi-stimuli response, which further improves the security of information. Our work provides a new insight for designing advanced materials and can be expected to inspire future studies to explore optical anti-counterfeiting technology.
Keywords: Anti-counterfeiting; Persistent luminescence; Thermo-luminescence; Tunable luminescence.
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