Effect of NH4F Flux on Structural and Luminescent Properties of Sr2SiO4:Eu2+ Phosphors Prepared by Solid-State Reaction Method

Sr2SiO4:Eu2+ phosphors were prepared by a conventional solid-state reaction method at a relatively low temperature (1100 degrees C) by using NH4F as a flux. The effect of NH4F flux and Eu2+ doping concentrations on the structural and luminescent properties of Sr2SiO4:Eu2+ was investigated in detail. The structural properties were studied by X-ray diffraction and a field-emission-scanning electron microscope. The blueshift of emission peaks with different Eu2+ concentrations was observed and analyzed. The NH4F flux increased the content of monoclinic beta-Sr2SiO4 phase and enhanced the luminescent performance of Sr2SiO4:Eu2+ phosphor significantly, and the NH4F flux is more superior to the NH4Cl and Li2CO3 fluxes. Our investigation indicates that Sr2SiO4:Eu2+ is a good light-conversion phosphor candidate for near-UV chip and that NH4F is a good flux for beta-Sr2SiO4:Eu2+. (C) 2010 The Electrochemical Society. [DOI:10.1149/1.3454723] All rights reserved.