Excitation spectra of a long-persistent phosphor SrAl2O4 : Eu, Dy in vacuum ultraviolet region

This work has been carried out to understand the phosphorescence mechanism of the new-type long-persistent phosphor SrAl2O4 : Eu, Dy. Luminescence and excitation spectra were obtained by using vacuum ultraviolet (VUV) light as an excitation source. It is suggested that the 450 and 520-nm luminescence bands in SrAl2O4 : Eu, Dy excited with the VUV light may be attributed to the host sensitization. Creation spectrum of the long-persistent phosphorescence was firstly obtained in the VUV region by measuring the after-glow luminescence. A prominent peak was observed around 200 nm, namely in the low-energy tail of the fundamental absorption of SrAl2O4, indicating that the phosphorescence mechanism in SrAl2O4 : Eu, Dy may be closely related to the defect formation. (C) 2000 Elsevier Science B.V. All rights reserved.