Luminescent characteristics and microstructures of Sr2CeO4 phosphors prepared via sol–gel and solid-state reaction routes

Abstract

Blue-light-emitting Sr2CeO4 phosphors were synthesized via a sol–gel process and the conventional solid-state method in this study. The developed sol–gel process lowered the synthesis temperature of monophasic Sr2CeO4 to as low as 900 °C. In comparison with the solid-state derived powders, the sol–gel derived powders had more uniform morphology and smaller particle sizes. In addition, sol–gel derived Sr2CeO4 displayed higher luminescent intensity than that prepared via the solid-state route under the same heating conditions. This is attributed to the improved compositional homogeneity and crystallinity in the sol–gel process. During the heating processes, Sr2CeO4 tended to thermally decompose at elevated temperatures. This decomposition reaction resulted in the formation of an impurity phase- SrCeO3 and thereby a decrease in the luminescent intensity. For obtaining Sr2CeO4 phosphors with high luminescent intensity, the heating conditions in both processes need to be well modulated.