The persistent energy transfer of Eu2+ and Mn2+ and the thermoluminescence properties of long-lasting phosphor Sr3MgSi2O8:Eu2+, Mn2+, Dy3+

Eu2+, Mn2+ and Dy3+ co-doped long-lasting phosphors Sr3MgSi2O8 were prepared by a solid-state reaction under a reductive atmosphere. Fluorescence spectra demonstrated that the weak red emission resulting from the forbidden transition of Mn2+ could be enhanced by the energy transfer from Eu2+ to Mn2+. The energy transfer between Eu2+ and Mn2+ was systematically investigated. The phosphorescence spectra revealed that Eu2+ could persistently transfer its energy to Mn2+ after removing the excitation source. The duration of Mn2+ can prolong to more than 2 h. The thermoluminescence spectra were used to characterize the ability of the trap to trapping the carriers. By the analysis of the ionization potentials, the roles of Mn2+ and Dy3+ in the afterglow process were discussed. A possible afterglow mechanism was presented and discussed.

► Through the energy transfer from Eu2+ to Mn2+, the duration of Mn2+ can prolong to more than 2 h.
► The electron trap plays a dominate role for the long-persistence phosphorescence.
► The Sr3MgSi2O8:Eu2+, Mn2+, Dy3+ can be a promising candidate for the red-light long-lasting phosphor.