Photoluminescence of Eu2+-doped CaMgSi2xO6+2x (1.00⩽x⩽1.20) phosphors in UV-VUV region

Alkaline-earth silicate phosphors CaMgSi2xO6+2x:Eu2+ (1.00⩽x⩽1.20) were prepared by traditional solid-state reaction. The phosphors showed an intense blue emission centered around 453 nm, with both 254 and 147 nm excitations. The host absorption below 200 nm in the excitation spectra consisted of two bands around 160 and 190 nm. The band around 160 nm was ascertained to be associated with the SiO4-tetrahedra and MgO6-polyhedra, and that around 190 nm was due to the CaO8-polyhedra or some impurities. The incorporation of excess Si of less than 15% would not lead to formation of impurities and the results indicated that an appropriate Si excess could improve the Photoluminescence (PL) intensity in both ultraviolet (UV) and vacuum ultraviolet (VUV) regions