Thermal Analysis and Luminescence Properties of the Europium doped Sr2SiO4 Phosphor

Abstract

The thermal analysis for Sr2SiO4 phosphor during solid state diffusion method is investigated using an isothermal method. The starting materials Strontium carbonate SrCO3 and silicate SrCO3 are used to prepare Sr2SiO4 Phosphor TG/DTA and XRD analysis suggest a direct reaction between SrCO3 and SrCO2 powders. The conversion ratios of the Sr2SiO4 starting materials are calculated from the weight loss. Based on the reaction kinetic isothermal analysis, Sr2SiO4 formation is corroborated as controlled by the Brounshtein-Ginstling’s diffusion-controlled model. The purpose of this study is to elucidate the reaction mechanism and reaction kinetics of formation of Sr2SiO4 in a solid-state diffusion. The precursors were examined using thermal and X-ray diffraction analysis to determine the optimum reaction range. The isothermal analysis was adopted to understand the reaction mechanism and kinetics. Using the microstructural observations accompanied by the kinetics, a reaction model for the formation of Sr2SiO4 via the solid-state reaction is proposed. The emission spectra shows broad band peaking at 612 nm for the excitation wavelength 254 nm. Color co-ordinates of Sr2SiO4: 1.0% Eu3+ are x = 0.67 and y = 0.32, it is in red color region. Sr2SiO4: 1.0% Eu3+ phosphor is very appropriate red emitting phosphor for white-emitting diodes.