Synthesis and luminescence properties of BaSO4 phosphor activated with Sm

BaSO 4 phosphor activated with Sm are prepared by the high temperature solid state reaction method in air, and its crystal structure, morphology, and luminescence properties are investigated. Broadband PLE spectrum are observed within the range 250–580   nm owing to mainly the 4f–5d transitions of Sm 2+ ions, and PL spectrum consists seven emission bands in the range of 550–780   nm owing to mainly 5 D 0   →   7 F J ( J   =   0, 1, 2, and 3) transitions of Sm 2+ ion and 4 G 5/2   →   6 H J ( J   =   5/2, 7/2, and 9/2) transitions of Sm 3+ ions. Sm 2+ ions can exist steadily in BaSO 4 :Sm phosphor sintered at different temperature and time in air. The optimum Sm 2+/3+ doping concentration, sintering temperature and time are about 2   mol%, 800   °C and 30   min, respectively. The luminous mechanisms are discussed by the schematic energy level diagrams of Sm 3+ and Sm 2+ ions.