Violet blue emission and thermoluminescence glow curve analysis of Gd2SiO5:Ce3+ phosphor

Abstract

This paper reports synthesis of Ce3+ ions-doped Gd2SiO5 phosphor powders prepared by modified solid state reaction method, which is most suitable method for large-scale production. Starting materials used for sample preparation were Gd2O3, SiO2 and CeO2 with variable concentration of cerium (0.1mol% to 2.5mol%) with fixed amount of boric acid (0.05mol%) as flux. PL excitation spectra was found at 260nm while the emission spectra was found at 365, 378, 555, 602, 607 and 627nm for lower Ce3+ doping concentration which are attributed to the Gd3+ ion transitions. For higher concentration of Ce3+ we get broad emission spectra from 350 to 550nm which is characteristics of Ce3+ ion transition. Commission Internationale de l’Eclairage co-ordinate (CIE) of this phosphor is x=0.170, y=0.029, in the violet region for 2.5mol% of cerium. TL glow curves were recorded for different doses of UV exposure and gamma ray dose at a heating rate of 5°Cs−1. The kinetic parameters such as activation energy “E”, the order of kinetics “b”, and the frequency factor “s” of Gd2SiO5:Ce3+ have been calculated by using peak shape method. Sample shows general order kinetics for most of the peaks. The effect of Ce3+ concentration on TL intensity was also studied and found that the intensity is maximum for 0.1mol% and then decreases with increasing concentration of Ce3+. The present phosphor can acts as a single host for violet-blue emission (2.5mol%) for display devices as well as may be used for thermoluminescence dosimetric material under UV & gamma dose.