Synthesis of Long Afterglow SrAl2O4: Eu2+, Dy3+ Phosphors Through Microwave Route

A novel and fast microwave route is used for the synthesis of SrAl₂O₄: Eu²⁺, Dy³⁺ powder phosphors. Based on the XRD peaks, the powder phosphors were identified as SrAl₂O₄ phase, which is monoclinic (a = 8.4424Å, b = 8.822 Å, c = 5.1607Å, = 93.415°). Compared with those synthesized by solid-state reaction process, the phosphors show a smaller grain size (about 4.8 m). It exhibited broadband peaks in both the excitation and emission spectra. A clear blue shift occurs in the excitation and emission spectra of these phosphors compared to those synthesized by solid-state reaction process. The excitation peaks lied between 300 nm and 450 nm, and the main emission peaks lied around 507 nm. The afterglow curve shows that the initial luminescent intensity of the phosphors synthesized through microwave route decreases greatly.