Enhanced luminescent properties and optical absorption of γ-irradiated KI: Ce3+, Tb3+ crystals

This paper reports that KI doped with Ce3+ or double doped with Tb3+ and Ce3+ were prepared by the Bridgman–Stockbarger method and characterized by optical absorption photoluminescence (PL), thermoluminescence (TL), photostimulated emission (PSL) and TL emission. The optical absorption measurement indicates that F and V1, V2 centers are formed in the crystals during the γ irradiation process. It was attempted to incorporate a broad band of Ce3+ activator into the narrow band emission of Tb3+ in the KI host without the reduction of emission intensity. Ce3+-co-doped KI and Tb crystals showed a broad band emission due to the d–f transition of Ce3+ and a reduction in the intensity of emission peaks due to the 5D3–7Fj (j=3,4,5,6) transition of Tb3+, when they were excited at 240 nm.