Dual emission of Ce 3 + ,Mn 2 + -coactivated Ca 3 YNa(PO 4 ) 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.