Phosphor-in-glass with time-evolving multicolor luminescence for dynamic anticounterfeiting

Abstract The conventional luminescent materials used in the anticounterfeiting field generally exhibit unicolor output and a single-wavelength excitation mode, resulting in a poor anticounterfeiting effect. Herein, we successfully achieved a new transparent SrAl2O4:Eu2+,Dy3+/CaAlSiN3:Eu2+ phosphor-in-glass (PiG) with dynamic luminescence color variation from red to yellow in hundreds of seconds during the ultraviolet lamp irradiation and green persistent luminescence (PersL) after ceasing excitation. Additionally, the prepared PiG owns excitation wavelength- or doping weight ratio-dependent color-tunable luminescence. As a proof-of-concept experiment, the specially designed SrAl2O4:Eu2+,Dy3+/CaAlSiN3:Eu2+ PiG based flower patterns exhibit dynamic luminescence color variation under a simple ultraviolet lamp, and can be observed for quick discrimination. This work exploits a new perspective for the design of dynamic multicolor anticounterfeiting materials.