The Synthesis And Study Of Red Long Afterglow Phosphors

With the development of SrAl2O4 Eu2+, Dy3+ yellow-green long afterglow phosphor, the preparation and characteristic of red long afterglow were paid more attention. Not only the luminescence characteristic of the traditional red long afterglow phosphor CaS: Eu3+ could not be compare with SrAl2O4 Eu2+, Dy3+ long afterglow phosphor, but also it had instable characteristic in the exposure of moisture and sunlight. The above deficiency limited its application. The preparation and characteristic of two new kinds of stable red long afterglow phosphor CaTiO3:Pr3+and Y2O2S:Eu3+, Mg2+,Ti4+ were studied. The sintering method was applied in the preparation of phosphors, and the co-precipitation method was used in the preparation of the precursor Y2O3:Eu3+ of Y2O2S:Eu3+,Mg2+,Ti4+ phosphor. The spectrum, thermoluminescence glow curves, and the effect of activator and co-activator on the characteristic of phosphors were studied. The effect of Pr3+ molar ratio on the characteristic of CaTiO3.-Pr3+ red phosphor was studied. With the increase of Pr3+ molar, the concentration quenching effect of CaTiO3: Pr3+ red phosphor was obvious; The effect of Eu3+ molar ratio on the spectra character of Y2O2S: Eu3+, Mg2+, Ti4+ red phosphor were studied, with the increase of Eu3+ molar ratio, the transfer from the high activated states 5Dj(J=l,2,3) deteriorated gradually, co-activator Mg2+,Ti4+ had great effect on the afterglow character of Y2O2S:Eu3+, Mg2+,Ti4+phosphors. The dopant Ti4+ contributed to the formation of deep energy trap, while Mg2+ acted as the charge compensator of Ti4+. The preparation of Y2O2S: Eu3+, Mg2+, Ti4+ phosphor by co-precipitation method and its characteristic were also studied, this method was beneficial to the dopant of activator Eu3+.This article broadened the acknowledge of CaTi03:Pr3+ and Y2O2S:Eu3+. Mg2+, Ti4+ red long afterglow phosphors, and was beneficial to the application of these kinds of phosphors.