Microwave Sintering and Optical Properties of Sm3+-Activated KSrPO4 Phosphors

The microwave sintering and photoluminescence properties of KSr1−xPO4:xSm3+ phosphors have been investigated. KSrPO4 phosphates activated by various concentrations of Sm3+ ions (x = 0.007, 0.009, 0.01, 0.03) were microwave sintered at 1200°C for 3 h under air atmosphere. x-Ray diffraction patterns showed that all phosphor samples exhibited a single phase without any extraneous phases. Scanning electron microscopy images showed that the particle size increased with the Sm3+ concentration and that the particle morphology was fine and uniform. The photoluminescence results showed that a concentration quenching effect occurred when the concentration of Sm3+ ions reached x = 0.01. Decay time measurement results showed that the lifetime decreased gradually from 3.12 ms to 2.34 ms as the Sm3+ concentration increased. All the chromaticity (x, y) values of the microwave-sintered KSrPO4:Sm3+ phosphors were located in the red region (0.57, 0.41).