Triple-Modal Anti-Counterfeiting Based on CsPbBr₃ Perovskite Quantum Dot/CaAl₂O₄:Eu²⁺, Nd³⁺ Composites with Dual Fluorescence Properties

Abstract

Advanced fluorescent anticounterfeiting technology has received widespread attention due to the lack of sufficient security of traditional anti-counterfeiting. Hence, there is a great challenge to continuously develop multi-level anti-counterfeiting technology with higher security. Here, we develop a desired fluorescent anticounterfeiting technology based on CsPbBr3 perovskite quantum dots (PQDs) and CaAl2O4:Eu2+, Nd3+ composites with persistent luminescence properties. CsPbBr3 PQDs can be formed on the surface of the CaAl2O4 host and exhibit an average diameter of around 3.5 nm. The photoluminescence (PL) intensity of CsPbBr3 PQDs/CaAl2O4 composites is greatly enhanced to 125 times compared to that of pure CsPbBr3 PQDs, and the desired narrow FWHM of 19 nm is achieved under near-ultraviolet irradiation. Furthermore, highly stable CsPbBr3 PQDs/CaAl2O4:Eu2+, Nd3+ composites with triple-modal (UV, IR, and thermal) fluorescent anti-counterfeiting characteristics were developed and used in fabricating anti-counterfeiting labels through screen-printing technology. The results open up a pathway to enhance the photoluminescence properties and stability of perovskite quantum dots for the advanced fluorescent anticounterfeiting application.