Photoluminescence properties of Eu2+-activated Ca2Y2Si2O9 phosphor

Eu2+-activated Ca2Y2Si2O9 phosphors with different Eu2+ concentrations have been prepared by a solid-state reaction method at high temperature and their photoluminescence (PL) properties were investigated. Photoluminescence results show that Eu2+-doped Ca2Y2Si2O9 can be efficiently excited by UV–visible light from 300 to 425 nm. Ca2Y2Si2O9: Eu2+ exhibits broad band emission in the wavelength range of 425–700 nm, due to the 4f65d1 → 4f75d0 transition of the Eu2+ ions located at two different sites ((Ca/Y)1 and (Ca/Y)2) in Ca2Y2Si2O9. The effect of the Eu2+ concentration in Ca2Y2Si2O9 on the PL properties was investigated in detail. The results showed that the relative PL intensity reaches a maximum at 1 mol% of Eu2+, and a red-shift of the emission bands from these two different sites was observed with increasing Eu2+ concentration. Also there exists energy transfer between these two Eu2+ sites. The potential applications of Ca2Y2Si2O9: Eu2+ have been pointed out.