Optical anti-counterfeiting based on Cu+ and Sb3+ co-doped Cs2ZnCl4 single crystals

The transmission and protection of confidential information play an extremely important role in the field of information security. In the military field, optical anti-counterfeiting technology is widely used in aviation equipment, military communication, military reconnaissance, and so on. At present, simple optical anti-counterfeiting no longer meets current anti-counterfeiting needs. Therefore, it's necessary to develop multimodal, stable and low toxicity luminescent materials to meet higher levels of anti-counterfeiting needs. In this paper, Cu⁺ and Sb³⁺ were co-doped to Cs2ZnCl4 single crystals, which exhibited white and red emission under 254- and 365-nm UV excitation, respectively. Based on the multi exciton emission characteristics of Cu⁺ and Sb³⁺ co-doped Cs₂ZnCl₄ single crystals, a digital encrypted information transmission system was designed, achieving dual anti-counterfeiting. This provides a feasible solution for the development of new metal halides for optical anti-counterfeiting applications