Luminescence properties of Ca5Y3Na2(PO4)5(SiO4)F2:Eu phosphors

A novel Ca5Y3Na2(PO4)5(SiO4)F2 compound with apatite structure was synthesized by solid state reaction method. The crystal structure was characterized by X-ray diffraction and refined with Rietveld refinements. The luminescence properties of Ca5Y3Na2(PO4)5(SiO4)F2:Eu phosphors were also investigated. The results indicated that the Ca5Y3Na2(PO4)5(SiO4)F2:Eu phosphors prepared in reducing atmosphere contained both Eu2+ and Eu3+ ions, which could be identified from their characteristic emissions. Upon UV light excitation, the emission spectrum including an asymmetric broad band of Eu2+ and several peaks of Eu3+ covered blue and red light regions, matched well with the spectrum required for plant growth. Thermal stability property was also investigated, and the results showed that Ca5Y3Na2(PO4)5(SiO4)F2:Eu exhibited good thermal stability. The luminescence spectra and time-resolved emission spectra indicated that there was no energy transfer between Eu2+ and Eu3+.