Effects of doping ions on afterglow properties of Y2O2S:Eu phosphors

In this paper, Y2O2S:Eu phosphors doped with Mg2+, Ca2+, Sr2+, Ba2+, Ti4+ were studied by photoluminescent spectra, afterglow spectra, XRD, decay curve, relative brightness and thermoluminescent spectra. The results show that those dopants do not change crystal structure of the host, but influence afterglow properties and relative brightness. Decay curve comprised of a fast and a slow part was found well exponential. It is considered that presence of shallow trap levels induced by interstitial oxygen atoms is responsible for the fast decay process while the deeper traps control the slow decay behavior.