Preparation and Study of Bright Orange-Yellow Long Persistent Luminescent Ca2LuScGa2Ge2O12:Pr3+ Phosphor

Long persistent phosphors are widely used in many fields, such as LED, bioimaging, urgent lighting, temperature sensors, etc. Although green and blue long persistent phosphors are well developed, efficient orange-yellow long persistent phosphors are still relatively rare. In this work, a novel orange-yellow long-persistent phosphors Ca2LuScGa2Ge2O12:xPr3+ (CLSGGO:xPr3+, x = 0.003, 0.005, 0.01, 0.02, 0.03, 0.04, 0.05) are prepared and systematically investigated through its crystal structural information, photoluminescence, and persistent luminescence properties. Under ultraviolet light excitation, these phosphors exhibit orange-yellow emission stemming from the 3P0 and 1D2 multiple electron transitions in the 4f level of Pr3+ ion. In addition, the material exhibits bright persistent luminescence. The complex garnet matrix structure of Ca2LuScGa2Ge2O12 provides excellent conditions for the formation of traps. Through the testing of thermoluminescence curve and function fitting, the density and depth of traps are studied; also, the storage and release process of carriers in the material are calculated in detail. A reasonable persistent luminescence mechanism is proposed for CLSGGO:0.01Pr3+. This work enriches the research content of photoluminescence and long persistent luminescence of Pr3+-doped garnet-based phosphors and paves the way for the future research of long persistent luminescent materials doped with rare earth ions.