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

Abstract

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.