Synthesis and Luminescent Properties of Sr2SiO4 Phosphors

Abstract

Sr2SiO4:Eu2+ phosphors and Sr2SiO4:Eu2+, Dy3+ persistent phosphors were synthesized by solid-state reaction method at 1300°C using SrCO3, SiO2(silica: 3 μ m and fumed silica: 7nm), Eu2O3(0.01 to 0.06 mol% Eu) and Dy2O3(0.005 to 0.02 mol% Dy) powders. The amount of the stable β- Sr2SiO4 phase had decreased and the amount of the α'-Sr2SiO4 increased with the increase of the Eu content. The solid solution of Eu2+ ion stabilized α'-Sr2SiO4 at room temperature. The emission color of the Sr2SiO4:Eu2+ products changed from the turquoise blue to yellow with the increase of the Eu content. The maximum emission peak position changed to the higher wavelength with the increase of the Eu content. The emission peak at 490nm(green color) was from β- Sr2SiO4 phase and that at 560nm(yellow color) was from α'-Sr2SiO4 phase. The change of the phase content in the products affects the color and the emission peak. The emission intensity of the products from fumed silica is stronger than the products from silica. Sr1.98−xSiO4:Eu0.02, Dyx persistent phosphors products showed the persistent emission for a few minutes with the naked eyes. The behavior was observed from all products. The product from fumed silica at x = 0.01 showed the strong emission for tens of seconds.