Sol–gel synthesis and luminescence characteristics of Sr(3−(2x+y))MgSi2O8: (Ce3+,Li+)x, Euy2+ phosphor for solid state lighting

Abstract The Sr(3−(2x+y))MgSi2O8: (Ce3+, Li+)x, Euy2+ phosphors were prepared using urea assisted sol–gel method, calcined under carbon reducing atmosphere. The Ce3+ ion concentration was fixed at 0.01 mol and Li+ ion was used as the charge compensator for Ce3+ ion. The Eu2+ ion concentration was varied as 0.005, 0.01 and 0.02 mol to realize the optimum emission, and it was found that the critical concentration is 0.01 mol. The Sr3MgSi2O8: Ce3+0.01, Li+0.01 phosphor showed the characteristic 4f05d1–4f1 transition of Ce3+ at 414 nm, which could be due to the occupation of Ce3+ at Sr2+ site, whereas Sr3MgSi2O8: Eu2+0.01 phosphor showed the characteristic 4f65d1–4f7 transition of Eu2+ at 470 nm and 570 nm, which were attributed to the occupation of Eu2+ ion at Sr2+ (I) site and Sr2+ (II, III) sites respectively. Codoping of Ce3+ ion with Eu2+ ion enhanced the emission intensity compared to the Ce3+ alone and Eu2+ alone doped Sr3MgSi2O8. It showed both the blue emission of Ce3+ and blue-green to orange emission of Eu2+ with the peak maximum at 460 nm, which could be due to the occupation of Ce3+ and Eu2+ ion in the Sr2+ site respectively. The CIE chromaticity coordinates measured on the Sr3MgSi2O8: Ce3+, Li+, Eu2+ phosphors excited under ultraviolet (365 nm) source showed the values lie in cool white light region could be applied to solid state lighting.