Synthesis and photoluminescence of new phosphors M2(Mg, Zn)Si2O7:Mn2+ (M = Ca, Sr, Ba)

New phosphors M2(Mg, Zn)Si2O7:Mn2+ (M = Ca, Sr, Ba) were prepared by sol–gel process, and their luminescent properties in ultraviolet and vacuum ultraviolet region were investigated. The results showed that the (Ca, Sr, Ba)2MgSi2O7:Mn2+ samples did not emit any visible light; the Sr2ZnSi2O7:Mn2+ and Ca2ZnSi2O7:Mn2+ samples showed green light. The Ba2ZnSi2O7:Mn2+ sample mainly showed green light under 254 nm excitation and red light under 147 nm excitation. The different emission was due to the Mn2+ ions occupied different sites, which were excited selectively. Among the three phosphors Sr2ZnSi2O7:Mn2+ showed the highest green emission intensity, and its decay time was shorter than that of Zn2SiO4:Mn2+ under 147 nm excitation.