Papers by Author: Qing Feng Liu

Abstract: Ba0.5Sr0.5TiO3:Pr powders co-doped with and without Al were synthesized by citrate-nitride combustion process. To investigate the effect and mechanism of Al dopant, samples with various Al3+ and Pr3+ content were prepared. The excitation and emission spectra were detected. Enhanced red emission around 613 nm was obtained by Al addition. Moreover, an emission at 491 nm was observed. Substitute situation of Pr3+ ions in the lattice was discussed. And the mechanism of energy transition was explained by the model of an intermediate charge transfer state.

Abstract: Nano-scale Gd2O3:Eu phosphor powders were synthesized by combustion method. In this process, the grain sizes of nano-scale Gd2O3:Eu were controlled by changing the amount of citric acid. Compared with micro-scale powders obtained from co-precipitation process, XRD revealed that the lattice parameter of nano-scale powders Gd2O3:Eu decreased. Further detailed study show that the luminescent properties were related to the grain size of nano Gd2O3:Eu powders under UV excitation.