Novel photoluminescence properties of Eu3+ doped chlorapatite phosphor synthesized via sol-gel method

Chlorapatite phosphors having formula Ca(9.97-x)(PO4)(6)Cl-1.94:xEu(3+) (x = 0.05 mol%, 0.1 mol%, 0.3 mol%, 0.5 mol%, 0.7 mol% and I mol%) were synthesized by sol-gel synthesis method. X-ray diffraction (XRD) pattern of the synthesized sample was obtained to ensure the formation of compound. Crystallographic study was done by performing Rietveld refinement analysis. Surface morphology of the compound was examined by obtaining scanning electron microscopy (SEM) images. Photoluminescence (PL) emission spectra show intense emission peak at 574 nm and relatively less intense peaks at 601 nm, 623 nm and 629 nm with 461 nm excitation. Emission peak located at 574 nm is very intense in this compound which is rarely observed for Eu3+ ions doping. PL decay is obtained and site selective transition of Eu3+ ion in apatite host is discussed. Commission International de I'Eclairage (CIE) chromaticity color coordinates of this phosphor were calculated. CIE-chromaticity color coordinates shows yellowish-orange emission of the phosphor.