Luminescent properties and energy transfer of thermal stable Ca10Na (PO4)7:Ce3+, Mn2+ red phosphor under UV excitation

A new red phosphor Ca10Na(PO4)7:Ce3+, Mn2+ was synthesized by a solid-state reaction method. Its luminescent properties were investigated by excitation/emission spectra and decay curves. Ca10Na(PO4)7:Ce3+ exhibits strong violet emission under UV excitation. For Ce3+, Mn2+ co-doped Ca10Na(PO4)7, the Mn2+ red emission is enhanced dramatically with the optimum Ce3+ co-doping. The energy transfer from Ce3+ to Mn2+ was proposed to be of resonance-type via an electric dipole-dipole mechanism, and the energy transfer efficiency was also calculated by decay data. The relationship between occupied sites and emission peak shift of Mn2+ ion in the Ca10Na(PO4)7 lattice was identified and discussed. Ca10Na(PO4)7:Ce3+, Mn2+ exhibits strong sensitized Mn2+ red emission and excellent thermal stability, which can serve as a good candidate for UV-excited red emitting phosphor.