Investigation on Eu3+ doped Sr2MgSi2O7 red-emitting phosphors for white-light-emitting diodes

In this work, we report the high temperature solid-state synthesis of red phosphors Sr2MgSi2O7: Eu3+ with various Eu3+ concentrations. Their luminescent properties at room temperature are investigated. The X-ray diffraction patterns indicate that the red phosphors powder conforms to the tetragonal Sr2MgSi2O7. Impurity structure appears when more than 20% Eu3+ is doped. The samples show a strong emission line at 615 nm and the intensity increases with the increase of Eu3+ concentration until concentration quenching occurs. Charge compensation assists in the reduction of the impurity structure and vacancies; hence the luminescent intensity is enhanced. The decay measurement indicates that the lifetime of Eu3+ emission is about 2–3 ms. Some of the Eu3+ can be reduced to Eu2+; this is also discussed.