Time-dependent dynamic photoluminescence of Eu3+-activated MgGa2O4 for advanced luminescence anticounterfeiting

In the modern society, luminescence anticounterfeiting plays a key part in information transmission. Nevertheless, most of the present luminescence anticounterfeiting logos are based on static photoluminescence (PL), which is easily counterfeited by substitutes. In this work, a time-dependent dynamic PL material, MgGa2O4:Eu3+, was successfully prepared. Under a portable 254 nm ultraviolet (UV) lamp irradiation, the PL color of the materials dynamically changes from red to pink to blue. After ceasing the UV irradiation, the blue persistent luminescence (PersL) with different afterglow time and bright was observed. The investigation reveals that the dynamic PL derives from the diverse time-dependent intensities of the MgGa2O4 trap-related emission and the Eu3+ 4f-4f transitions, and the Eu3+ dopant can introduce more traps into the host and consequently manipulate the dynamic PL and the PersL performances. The dynamic luminescent anticounterfeiting properties of the prepared material MgGa2O4:Eu3+ was investigated by a powder filling method, demonstrating the potential for applications in advanced anticounterfeiting.