Ce[sup 3+],Dy[sup 3+] Co-Doped White-Light Long-Lasting Phosphor: Sr[sub 2]Al[sub 2]SiO[sub 7] Through Energy Transfer

White-light long-lasting phosphor Sr 2 Al 2 SiO 7 : Ce 3 + , Dy 3 + was prepared by a high temperature solid-state reaction. The energy transfer between Ce 3 + and Dy 3 + was systematically investigated. Through co-doped Ce 3 + and Dy 3 + , the duration of the persistent luminescence of Sr 1.975 Al 2 SiO 7 : Ce 0.005 , Dy 0.03 reached nearly 50 min. The decay curves and thermoluminescence spectra were used to characterize what kind of trap existed in the sample. A possible afterglow mechanism was presented and discussed. This work provides a promising approach for the development of white-light long-lasting phosphor.