Highly transparent Ce3+,Cr3+ co-doped GYAGG single crystals with enhanced persistent luminescence

Despite significant interest in persistent luminescence materials, the focus of all recent works remains on the exploitation of materials in powder form. Here, a new point of view based on persistent luminescence in single crystals is presented. The garnet crystals [(Gd0.67Y0.33)3-xCex)](Al2-yCry)Ga3O12 and [(Gd0.33Y0.67)3-xCex](Al2-yCry)Ga3O12 (GYAGG) codoped with Ce3+ and different concentrations of Cr3+ have been elaborated and their persistent luminescence properties are fully characterized within this work. The persistent luminescence of Ce3+, Cr3+-codoped GYAGG single crystals is optimized due to their high optical quality, very good crystallinity and a volume effect where the whole material can be excited and charged by the excitation light. Furthermore, thanks to their transparency, robustness and homogeneity; in-depth optical spectroscopy characterization is possible, shedding light on the mechanism responsible for the afterglow.