Photostimulated Ultraviolet Luminescence for Anti‐Counterfeiting in Daylight Conditions

Abstract Photostimulated luminescence in the ultraviolet (PSL‐UV) holds promise for high‐security anti‐counterfeiting applications, especially in brightly lit environments. Despite its potential, research on PSL‐UV is relatively limited. Here, the PSL‐UV properties of a NaYF 4 :Gd 3+ fluoride‐based phosphor is explored, demonstrating its suitability for advanced anti‐counterfeiting purposes. This phosphor effectively captures excitation energy from X‐rays and subsequently emits UV light at 311 nm when stimulated by visible ambient light. Remarkably, the material exhibits exceptional reliability and durability, maintaining effectual PSL‐UV output even after enduring exposure to 100 cycles of ambient light and subsequent decay. Furthermore, ultraviolet imaging experiments highlight the practicality of PSL‐UV for real‐world implementation, presenting a fresh and robust strategy for enhancing security and authentication processes.