Afterglow phenomenon in erbium and titanium codoped GD2O2S phosphors

A series of new long-lasting phosphor Gd2O2S:XEr,Ti are prepared by the conventional high-temperature solid-state method and their luminescent properties are systematically investigated in this paper. The characteristic afterglow emission of Er, which is due to the transition of F-4(9/2) -> I-4(15/2) and S-4(3/2) -> I-4(15/2), is reported for the first time. XRD, photoluminescence, long-lasting phosphorescence and decay curves are used to characterize the synthesized phosphors. The possible energy transfer mechanism of Gd2O2S:xEr,Ti is also investigated. (c) 2005 Elsevier B.V. All rights reserved.