[Luminescence spectra of Sm3+ doped Sr2CeO4 synthesized through co-precipitation process]

The precursor powders of Sn3+ doped Sr2CeO4 were obtained by the application of (NH4)2C2O4 as a precipitant. After calcinations, the precursor powders became a white emitting fluorescent material. The XRD and emission spectra manifest that the optimum temperature and Sm3+ concentration for synthesizing Sr2CeO4:Sm are 1 050 degrees C and 1 mol%, respectively. The better the phosphor powders crystallize, the higher their emission intensities are. The excitation spectrum implies that the transition emissions of Sm3+ at 608 and 654 nm originate from the Ce4+ -O(2-) charge transfer (MLCT) resulting from the interaction of Ce4+ and the neighboring O2-. Therefore, it can be concluded that the host Sr2 CeO4 acts as a sensitizer, which transfers the energy to Sm3+. The emission intensity of the phosphor synthesized through co-precipitation is much higher than that of phosphor prepared using conventional solid state reactions.