Synthesis of SrLu2O4:Eu2+ red phosphors and their photoluminescence properties

New red-emitting Eu2+-doped SrLu2O4 phosphors were synthesized by a solid state reaction, and the effects of starting material composition, annealing temperature, and Eu2+ doping concentration on the phase formation and photoluminescence (PL) properties were investigated. A single phase SrLu2O4:Eu2+ phosphor was obtained between 1400 and 1500 °C in Sr-rich condition under 5% H2/N2 atmosphere. As-synthesized SrLu2O4:Eu2+ phosphors exhibited a strong red emission centered at 610 nm under the excitation of λex=450 nm. The highest emission intensity was observed in 0.004 mol Eu-substituted composition, which was ~85% compared to that of commercial (Sr,Ca)AlSiN3:Eu2+ phosphor. SrLu2O4:Eu2+ phosphors showed a strong thermal quenching, which suggests a high potential as an optical temperature sensor.