Investigation of structural and luminescent properties of Ce3+/Mn2+ ions-doped Ca5(PO4)3F

Ce3+/Mn2+ ions-doped oxyapatite calcium fluorapatite [Ca5(PO4)3F, FAP] has been successfully synthesized by a facile one-step hydrothermal method. The luminescent properties of Ce3+- and Ce3+/Mn2+- activated FAP phosphors were investigated using the photoluminescence (PL) and photoluminescence excitation (PLE) spectra. The emission of Ce3+ was fitted by two Gaussian functions with dashed lines in wavenumber to confirm the Ce3+ ion simultaneously to occupy the 4f and 6h sites in Ca5(PO4)3F host, which was consistent with the calculated results of crystal field based on chemical bond theory. In addition, the existence of Ce3+ (sensitizer) can dramatically enhance the green emission of Mn2+ (activator) in Ce3+/Mn2+ ions co-doped samples due to an efficient energy transfer from Ce3+ to Mn2+. All of these results could help us understand the site assignments and optical properties of the rare earth ions doped in hexagonal Ca5(PO4)3F.