Color-tunable Eu 2+ activated oxysilicate phosphors with oxyapatite structure

Color-tunable Eu 2+ activated oxysilicate phosphors with a general formula M 3.85 La 6 (SiO 4 ) 6 O:Eu 2+ 0.15 (M = Mg, Ca, Sr, Ba) were synthesized for the first time by solid-state reaction at high temperature under reducing atmosphere. The influence of alkaline earth metal ions on the crystal structure and photoluminescence characteristics have been investigated by the measurement of XRD and photoluminescence characteristics. The results have indicated that all the phosphors were oxyapatite structure belonging to P63/m space group and cell parameters increase in order of Mg < Ca < Sr < Ba. According to the photoluminescence spectra, the peak wavelength and FWHM of emission bands have been changed by varying M ions in the host lattices, result in the emission color have been changed. The detailed explanations have been well suggested by crystal structure and covalent effect.