LAUSR

Understanding the effect of electron-transfer quenching on the photoluminescence (PL) of phosphors is important but often underestimated. Here we study the PL of two Pr3+-doped phosphors, MgGeO3:Pr and MgSiO3:Pr, which share analogous chemical formulas but exhibit different PL performances. Ultraviolet and red emissions dominate the PL of MgSiO3:Pr at room temperature, while the ultraviolet emission is absent in MgGeO3:Pr. A photoionization experiment, which is based on thermoluminescence excitation spectroscopy, reveals that an impurity-trapped exciton state quenches the 4f5d state of Pr3+ in MgGeO3. We believe that the present experimental approach, as well as the associated physical insight on the electron-transfer quenching, is generally applicable for many existing phosphors.