Enhanced Persistence Properties through Modifying the Trap Depth and Density in Y3Al2Ga3O12:Ce3+,Yb3+ Phosphor by Co-doping B3+

Long persistence phosphors with high emitting intensity are promising materials for safety signage and energy storage applications. Herein, an improved persistent luminescence of Y3Al2Ga3O12 phosphor by co-doping Ce3+, Yb3+, and B3+ is achieved using conventional solid-state reaction. On one hand, the incorporation of H3BO3 can improve the crystallinity; on the other hand, B3+ can replace Al3+/Ga3+ in tetrahedral sites in the host lattice, causing lattice contraction and modifying the trap depth and density. It is found that adding B3+ forms a much deeper trap with ∼1.10 eV depth. In addition, the density of the electron trap can also be dramatically increased compared to the sample without B3+. The charging process for persistent luminescence is demonstrated by comparing the photoluminescence excitation spectrum with the thermoluminescence excitation spectrum. The persistence luminescence mechanism is given by a visual energy level diagram on the basis of the vacuum referred binding energy scheme of Y3Al2Ga3O12.