Crystal structure, photoluminescence properties and energy transfer of Ce3+, Mn2+ co-activated Ca8NaGd(PO4)6F2 phosphor

Ca(8−y)MnyNaGd(1−x)Cex(PO4)6F2 (CNGF: xCe3+, yMn2+) (0 ≤ x ≤ 0.05, 0 ≤ y ≤ 0.16) phosphors were synthesized by solid state reaction. The crystal structure was determined to be apatite-type by XRD refinement. The PLE and PL spectra showed that the energy transfer occurs between Gd3+ to Mn2+ and Ce3+ to Mn2+. And the energy transfer efficiency from Gd3+ to Mn2+ and Ce3+ to Mn2+ in CNGF had been analyzed. The research result revealed that the electric dipole–quadrupole interaction predominates in energy transfer mechanism from Ce3+ to Mn2+ in CNGF. The corresponding CIE coordinates revealed that CNGF: 0.02Ce3+, yMn2+ could be a good yellow phosphor.