Synthesis of high efficient Ca2SiO4:Eu2+ green emitting phosphor by a liquid phase precursor method

Green emitting Eu2+-doped Ca2SiO4 phosphors were synthesized by three different methods (a conventional solid state reaction (SSR) method, a novel liquid phase precursor approach using SiO2 sol (LPP-SiO2(sol)) and water-soluble silicon compound (LPP-WSS)). The obtained phosphors exhibited a broad excitation spectrum ranging from 225 to 450 nm and a strong green emission peak at 502 nm due to the 4f(6)5d(1)-> 4f(7)(S-8(7/2)) transition of Eu2+. The highest luminescent intensity was obtained for the samples fired at 1100 degrees C. The dependence of luminescence properties on Eu2+ concentration for the phosphors synthesized using LPP-WSS method was also examined from 0.1 to 5.0 mol% and the maximum emission intensity was observed at 3.0 mol% Eu2+. A detailed analysis using various characterizations revealed that phosphors produced by the LPP-WSS process exhibited more homogenous phase distribution and higher luminescence intensity than those from the other two processes, which suggested the potential application of Ca2SiO4:Eu2+ in white light-emitting diodes and fluorescence lamps. (C) 2011 Elsevier Inc. All rights reserved.