Enhanced photoluminescence of Eu3+-activated calcium molybdate system by co-doping Li+ and Si4+ ions

A novel red-emitting phosphor LixCa1-2xEuxSiyMo1-yO4 (0.22 <= x <= 0.32, 0 <= y <= 0.08) was synthesized by solid state reaction at 750 degrees C. The phosphors were characterized by X-ray powder diffraction (XRD) and photoluminescence spectra. The LixCa1-2xEuxSiyMo1-yO4 phosphors can be efficiently excited by 395 nm near ultraviolet and 465 nm blue light. The emission spectra exhibit intense red emission with the main emission peak at 617 nm and the chromaticity coordinates locate in the range of x = 0.667-0.668, y = 0.331-0.332 approaching the National Television System Committee (NTSC) standard values (x = 0.67, y = 0.33). The photoluminescence spectra showed that simultaneously co-doping Li+ and Si4+ ions in Eu3+-activated CaMoO4 system enhanced luminescence intensity compared with that of CaMoO4:Eu3+. (C) 2012 Elsevier B.V. All rights reserved.