Fabrication of Ce3+-Cr3+ co-doped yttrium aluminium gallium garnet transparent ceramic phosphors with super long persistent luminescence

YAGG:Ce3+-Cr3+ transparent ceramics (TCs) with different thicknesses were fabricated by solid state reaction and vacuum sintering. Compared with an opaque YAGG:Ce3+-Cr3+ ceramic phosphor of the same composition, the corresponding TC phosphors exhibited brighter persistent luminescence after ceasing blue excitation (460 nm) due to a typical “volume effect” of transparent materials. The duration that the persistent luminescence intensity reaches 2 mcd/m2 of the YAGG:Ce3+-Cr3+ TC was nearly twice of that of the compacted pellet made of SrAl2O4:Eu2+-Dy3+ commercial powder.