Synthesis of SrAl 2O 4Eu 2+,Dy 3+ phosphors by the coupling route of microemulsion with coprecipitation method

Abstract

Nano-sized SrAl 2O 4:Eu 2+,Dy 3+ phosphors with good monodispersity and narrow size distribution were synthesized by the coupling of water-in-oil (W/O) microemulsion with coprecipitation method. The phase composition, morphology, crystallinity, excitation spectra, emission spectra, and afterglow decay of SrAl 2O 4:Eu 2+,Dy 3+ nanophosphors were measured. It was found that the amount of surfactant that was used had an important effect on the shape and average size of the phosphor particles. SrAl 2O 4 phase of the phosphors showed an increase with the increase in calcination temperature. When the calcination temperature reached 1150°C, the fine crystal of SrAl 2O 4 was formed and the long afterglow luminescence could be obviously observed. In comparison with the samples prepared by the high-temperature solid-state method, the calcination temperature showed an obvious decrease and a clear blue shift occurred in the excitation and emission spectra of the sample. The afterglow time could be more than 8 h.