Photoluminescence properties of SrAl2O4 and CaAl2O4 long-phosphorescentphosphors synthesized by an oxalate coprecipitation method

Abstract

Long phosphorescent oxide phosphors have been synthesized through an oxalate coprecipitation method. For stoichiometry, the precipitates of hydroxyoxalates including metal ions were obtained at pH 10. Phosphorescent phosphors, “SrAl2O4:Eu, Dy” and “CaAl2O4:Eu, Nd”, were prepared by an oxalate co-precipitation method under a reducing atmosphere, showed the peaks of crystalline phases in XRD patterns. The photoluminescence spectra of the long phosphorescent phosphors were analyzed. For the excitation wavelength of 365 nm and 254 nm, the phosphors, SrAl2O4:Eu, Dy and CaAl2O4:Eu, Nd exhibited emission spectra around 514 nm and 476 nm, which are caused by the 5d-4f transition of the Eu2+ ions, respectively.