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 4F9/2→4I15/2 and 4S3/2→4I15/2, 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.