High temperature persistent luminescence in Tb3+ doped CaSr2Al2O6 phosphor

A novel green-emitting long persistent luminescence (LPL) phosphor CaSr2Al2O6:Tb3+ (CSA:Tb3+) has been developed by traditional solid-state reaction. The crystal structure, luminescence properties, decay curves and TL curves of CSA: Tb3+ are studied in this paper. The distribution of Ca, Sr, Al, O and Tb in phosphors was shown by elemental mapping and photoluminescence under fluorescence microscope. CSA: 0.05Tb shows the strongest luminescence, while CSA: 0.0075Tb exhibits the best LPL of 57 min. In order to study the mechanism of afterglow, the trap depth and distribution was analyzed by measuring the TL curves. By measuring the afterglow at high temperature, it is found that the afterglow also presents a high intensity at 464 K, indicating that CSA: 0.0075Tb3+ can be potentially applied above the room temperature.