| In this paper, the white LED phosphors and the Yb2+doped novel long persistentluminescence (LPL) materials are the investigating object. The phosphors based on silicate,sulphide, aluminate matrix were prepared by sol-gel and high temperature solid state reactionmethod. The crystal structures were analyzed. There is a study on the luminescence propertiesby changing the kinds of activator and the doped concentration. At the same time, the longpersistent luminescence properties were characterized by the afterglow decay curves,thermoluminescence (TL) curves etc.. The main contents are given below:(1) A series of CaO-Y2O3-SiO2:(Ce3+, Eu2+,Eu3+) oxyapatite phosphors were prepared viasol-gel technique. The X-ray diffraction spectra of CaO-Y2O3-SiO2:(Ce3+, Eu2+,Eu3+) wereinvestigated, and the results in different host lattice were compared. we have obtainedwhite-light by mixing the Ce3+, Eu2+and Eu3+activated yttrium silicate calcium phosphors ina certain mass ratio.(2) A novel BaS:Yb2+phosphor was synthesized by a solid stated reaction under the H2reduce atmosphere. The influence of the doping concentration on the luminescence wasinvestigated. The optimum concentration of Yb2+is0.1mol%, and we have given theluminescence mechanism of Yb2+in BaS.(3) The luminescence properties of Yb2+in SrS were analyzed, especially the propertiesof SrS:0.5%Yb2+. The result indicated that when excited by465nm, the long persistentluminescence in red (600nm) of Yb2+was observed in SrS:0.5%Yb2+phosphor.(4) The LPL properties of Yb2+based on MAl2O4(M=Sr, Ba) matrix were investigated.The space structure of MAl2O4(M=Sr, Ba) was analyzed by refinement. The data show thatthere are two kinds of metal cation in the cell. The long persistent luminescence of thephosphors was characterized by the afterglow decay curves and thermoluminescence curves.BaAl2O4:0.5%Yb2+has the longer long persistent luminescence time. We also investigated thefeasibility of long persistent luminescence phosphors used for the solar cells. |
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