Enhanced long persistence of Sr2SnO4:Sm3+ red phosphor by co-doping with Dy3+

We report the observation of long lasting red phosphorescence in Sr2SnO4:Sm3+ and Sr2SnO4:Sm3+, Dy3+ phosphors. The decay patterns of afterglow curves demonstrate that the afterglow time of Sr2SnO4:Sm3+ could be prolonged by the incorporation of Dy3+. The remarkable changes in the thermoluminescence glow curve exhibited that the first band responsible for the origin of the afterglow becomes the most prominent feature when Dy3+ added. In other words, the enhancement of the red afterglow in Sr2SnO4:Sm3+, Dy3+ compared with Sr2SnO4:Sm3+ could be ascribed to more appropriate traps (the hole-traps V ″ Sr ) created by the incorporation of Dy3+.