Structure and luminescence properties of Ce3+-activated BaLu2Al2Ga2SiO12 persistent phosphors for optical information storage

A novel BaLu 2 Al 2 Ga 2 SiO 12 :Ce 3+ persistent phosphor was designed and synthesized through hetero-valence substituting Ba 2+ -Si 4+ ion pair for Lu 3+ -Al 3+ one in the Lu 3 Al 3 Ga 2 O 12 . XRD and Rietveld refinement results confirm the garnet typed crystal structure. SEM information shows that the constituent elements are uniformly distributed on the irregular particles. Under 360 or 430 nm excitation, the samples exhibit broad emission bands peaking at 510 nm. The luminescence intensity reaches to the maximum at 6 mol% Ce 3+ doping content, and an internal quantum efficiency of 51.2% is achieved. The concentration quenching between Ce 3+ ions is mainly originated from exchange interaction. Moreover, the phosphors exhibit bright cyan afterglow for minutes after removing the blue-light excitation source. The persistent luminescence decay process is studied by thermoluminescence spectra. The persistent luminescence mechanism and optical information writing and reading process are also discussed to explore the application in optical information storage.