Influence on the long afterglow properties by the environmental temperature

Sr2MgSi2O7:Eu2+, Dy3+ (SMED) and Ba2MgSi2O7:Eu2+, Dy3+ (BMED) were synthesized with the solid-state reaction. The SMED shows long afterglow while the afterglow of BMED is not visible at room temperature. When the environmental temperature is 150 °C, the afterglow of SMED is not obvious while the BMED shows the long afterglow. The decay curves measured at different temperatures conform to this phenomenon. It ascribes to the different trap depths of different samples. The thermoluminescence (TL) curves of SMED peaks at 80 °C. BMED has two TL peaks peaking at about 80 and 175 °C respectively. The low temperature peak is weak and its density is small. The high-temperature peak reveals that one trap of BMED is deeper than the one of SMED. The afterglows of the phosphors strongly depend on the environmental temperature since the lifetime of the trapping carriers is temperature-dependence. BMED is a potential optimum long afterglow phosphor for the purpose of high-temperature application.