Enhancement of afterglow in SrAl2O4:Eu2+ long-lasting phosphor with swift heavy ion irradiation

We present a novel approach for improving the afterglow of long-lasting phosphors with swift heavy ion irradiation. The afterglow of famous long-lasting phosphor SrAl2O4:Eu2+ was dramatically enhanced with swift heavy ion irradiation. Furthermore, it was found that the enhancement was dependent on the electronic stopping power as well as the irradiation fluence. Thermoluminescence analyses revealed that the SHI irradiation had no significant influence on the trap depth, but increased the trap density in the phosphor. In addition, the mechanism underlying afterglow enhancement phenomenon was discussed.