The photoluminescence properties of Eu 3+,Bi 3+ co-doped yttrium oxysulfide phosphor under vacuum ultraviolet excitation

Abstract

Y 2O 2S co-doped with Bi 3+,Eu 3+ phosphors were prepared and their luminescence properties under vacuum ultraviolet (VUV) excitation were investigated. Much stronger red emission for Y 2O 2S:Eu 3+,Bi 3+ were observed under 147 nm excitation than that for Y 2O 2S:Eu 3+. Investigation on photoluminescence and calculation of electronic structure of Y 2O 2S:Eu 3+,Bi 3+ revealed that the Bi 3+ acts as a medium in energy transfer process and the great VUV luminescence enhancement of Y 2O 2S:Eu 3+ by doping Bi 3+ is due to effective energy transfer process: charge transfer (CT) transition of Y 3+–O 2− → Bi 3+ → Eu 3+. The Y 2O 2S:Eu 3+,Bi 3+ showed excellent optical properties when compared with the commercial (Y,Gd)BO 3:Eu 3+. Thus, the Y 2O 2S:Eu 3+,Bi 3+ would be a promising VUV-excited red phosphor.