Enhanced Photoluminescent Properties and Crystalline Morphology of LiBaPO4:Tm3+ Phosphor through Microwave Sintering Method

An investigation of the photoluminescent properties and crystalline morphology of blue emitting LiBa1−xPO4:xTm3+ phosphors with various concentrations (x = 0.005–0.030) of Tm3+ ions were synthesized by microwave sintering. For comparison, the LiBa1−xPO4:xTm3+ powders sintered at the same sintering condition but in a conventional furnace were also investigated. LiBaPO4 without second phase was formed no matter which furnace was used. More uniform grain size distributions are obtained by microwave sintering. When the concentration of Tm3+ ion was x = 0.015, the luminescence intensity reached a maximum value, and then decreased with the increases of the Tm3+ concentration due to concentration quenching effect. The microwave sintering significantly enhanced the emission intensity of LiBa1−xPO4:xTm3+ phosphors. Additionally, the d-d interaction is the key mechanism of concentration quenching for LiBaPO4:Tm3+. The chromaticity (x, y) for all LiBa1−xPO4:xTm3+ phosphors are located at (0.16, 0.05), which will be classified as a blue region.