Synthesis and luminescence properties of BaSO4 phosphor activated with Sm

BaSO4 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 Sm2+ ions, and PL spectrum consists seven emission bands in the range of 550–780 nm owing to mainly 5D0 → 7FJ (J = 0, 1, 2, and 3) transitions of Sm2+ ion and 4G5/2 → 6HJ (J = 5/2, 7/2, and 9/2) transitions of Sm3+ ions. Sm2+ ions can exist steadily in BaSO4:Sm phosphor sintered at different temperature and time in air. The optimum Sm2+/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 Sm3+ and Sm2+ ions.