Papers by Author: Li Mei Cao

Abstract: The luminescent properties of SrAl2O4 based materials were studied systematically, which emit long persisting phosphorescence with high brightness and show greater chemical stability than the traditional ZnS:Cu,Co phosphor. In order to obtain the better dispersed powders, SrAl2O4:Eu2+, Dy3+ was synthesized by a dipping process. The as-received samples are yellow-green in color and display better dispersion than those synthesized by the co-deposition method. The optimized conditions of this dipping process were explored. The luminescent properties and the crystal structure were studied in detail.

Abstract: Zn2SiO4:Mn2+ was synthesized via a dipping method. Stoichiometric high pure SiO2 was put into the solution of zinc nitrate and manganese nitrate. The mixture was milled while being heated until the water was vaporized completely. The as-received mixture was added into the ethanol, and dispersed well, then the mixture was milled and heated to remove the ethanol thoroughly by evaporation. The precursor were dried for several hours at 60°C, and annealed in a reducing atmosphere of active carbon at 1000°C for 4 h. As-prepared powders of Zn2SiO4:Mn2+ was tested by XRD and SEM. Its luminescent properties were characterized by excitation and emission spectra. The results are compared with those of Zn2SiO4:Mn2+ prepared by a general solid state reaction.