Color-Tunable CsCdCl3 Perovskite for Low-Temperature Anticounterfeiting and Information Storage Applications

Low-temperature anticounterfeiting technologies play a crucial role in ensuring the authenticity and integrity of temperature-sensitive products such as vaccines, pharmaceuticals, and food items. In this work, a low-temperature anticounterfeiting route based on the differentiated photoluminescence (PL), PersL, and thermally stimulated luminescence (TSL) behaviors of metal halide perovskite, pure CsCdCl₃, and CsCdCl₃:10% Te⁴⁺ is proposed. The CsCdCl₃ host exhibits pronounced color shifts, encompassing PL, PersL, and TSL behaviors, ranging from blue to yellow and orange as the temperature rises from 100 K to room temperature. This color change is attributed to a change in the luminous center (from the D_3d octahedron to the C_3v octahedron). Conversely, the addition of Te⁴⁺ as the luminescence center inhibits the matrix emission, maintains the characteristic orange emission of Te⁴⁺, and regulates the trap distribution of the matrix at low temperature and the TL luminescence intensity. This work highlights the significant promise of CsCdCl₃:10% Te⁴⁺ and CsCdCl₃ phosphors as innovative low-temperature anticounterfeiting technologies, especially for cold-chain vaccine safety monitoring.