Enhancement on the afterglow properties of Sr2MgSi2O7: Eu2+ by Er3+ codoping

The Sr1.99MgSi2O7: Eu2+0.01, and Sr1.97MgSi2O7: Eu2+0.01, R3+0.02 (R: Dy, Er) are synthesized via high temperature solid-state reaction. The sample without codoping shows the highest luminescent efficiency, leading to the strongest emission intensity. Both Dy3+ and Er3+ enhance the afterglow properties. Compared with Dy3+, sample doped with Er3+ shows a longer afterglow duration because of a deeper trap and it may be the optimum codopant for Sr2MgSi2O7: Eu2+ long afterglow phosphors.