Dual emission of Ce3+ ,Mn2+ -coactivated Ca3 YNa(PO4 )3 F via energy transfer: a single component white/yellow-emitting phosphor.

A series of Ce3+ ,Mn2+ -coactivated Ca3 YNa(PO4 )3 F phosphors were synthesized via a traditional solid-state reaction under a reductive atmosphere. X-Ray powder diffraction was used to confirm that the crystal structure and diffraction peaks of Ce3+ /Mn2+ -doped samples matched well with the standard data. A spectral overlap between the emission band of Ce3+ and the excitation band of Mn2+ suggested the occurrence of energy transfer from Ce3+ to Mn2+ . With increasing Mn2+ content, the emission intensities and lifetime values of the Ce3+ emission for Ca3 YNa(PO4 )3 F:Ce3+ ,Mn2+ phosphors linearly decrease, whereas the energy transfer efficiencies gradually increase to 89.35%. By adjusting the relative concentrations of Ce3+ and Mn2+ , the emission hues are tuned from blue to white and eventually to yellow. These results suggest that Ca3 YNa(PO4 )3 F:Ce3+ ,Mn2+ phosphors have promising application as white-emitting phosphors for near-ultraviolet light-emitting diodes.