Eu3+ red long afterglow in Y2O2S:Ti, Eu phosphor through afterglow energy transfer

Eu,Ti co-doped Y2O2S:0.03Ti,0.03Eu phosphors and single Eu or Ti doped Y2O2S phosphors were prepared and their luminescent properties were investigated in detail by photoluminescence (PL) spectra, long afterglow spectra and thermoluminescence spectra measurements. The results showed that Y2O2S:Ti,Eu phosphors possess orange-red afterglow color with afterglow time above 5 h. The reddish afterglow color, which corresponds to a set of linear Eu3+ emissions at low-energy range (540-630 nm), was demonstrated to come from the energy transfer process from yellow Ti afterglow emissions, the proposed energy transfer mechanism may well explain the Eu3+ afterglow emission.