Preparation and characterization of long afterglow M2MgSi2O7-based (M: Ca, Sr, Ba) photoluminescent phosphors

M2MgSi2O7:Eu, Dy (M: Ca, Sr, Ba) phosphors were prepared via sintering at 1300 °C for 3 h in a weak reductive atmosphere of flowing 5% H2–95% N2 gas. The emission spectra of these phosphors showed that the main emissions are peaking at 537.5, 475.6 and 500.3 nm due to 4f → 5d transitions of Eu2+. The decay curves indicated that all of these phosphors have long afterglow feature, especially Sr2MgSi2O7:Eu, Dy phosphor. It is the Dy3+ trap levels that resulted in the long afterglow in M2MgSi2O7 hosts.