Luminescence of SrY2O4:Eu3+ associated with defects

SrY2O4:Eu3+ phosphors were synthesized by both the solid-state reaction method and the sol-gel method, and their photoluminescence in vacuum ultraviolet (VUV) and the ultraviolet (UV) region were evaluated. The excitation spectra of SrY2O4:Eu3+ phosphors prepared by solid-state reaction show another excitation band centered at 324 nm except for the charge-transfer bands (CTB) of Eu3+ when monitored at 610 nm, and a blue emission band around 406 nm is observed when excited at 324 nm, which could be associated with defects. Both the excitation and emission bands mentioned above disappear when the samples were prepared by the sol-gel method. SrY1.98O4:0.02Eu(3+) phosphors synthesized by the sol-gel method exhibit a higher emission intensity under 147 nm excitation compared with solid-state reaction technology. The main reason could be that the samples prepared by the solution-based route have more regular and uniform morphologies.