Effect of europium doping levels on photoluminescence and thermoluminescence of strontium yttrium oxide phosphor

Abstract

The present paper deals with the effect of europium (Eu3+) doping concentration (0.1–2.5mol%) on photoluminescence (PL) and thermoluminescence (TL) of strontium yttrium oxide (SrY2O4) phosphor. The sample was prepared by the modified solid state reaction method, which is the most suitable method for large-scale production. The prepared phosphor sample was characterized by using X-ray Diffraction (XRD), field emission gun scanning electron microscopy, fourier transform infrared spectroscopy, high resolution transmission electron microscopy, photoluminescence, thermoluminescence and commission internationale de I׳Eclairage techniques. The PL emission was observed in the range of 410–630nm for the SrY2O4 phosphor doped with Eu3+. Excitation spectrum was found at 254 and 325nm, sharp peaks were found around 593, 615 and 625nm with high intensity. From the XRD data, using Scherrer׳s formula, calculated average crystallite size of Eu3+ doped SrY2O4 phosphor is around 32nm. Thermoluminescence study was carried out for the phosphor with UV and gamma irradiation. The TL response of SrY2O4:Eu3+ phosphor for two different radiations was compared and studied in detail. The present phosphor can act as a single host for white light emission in display devices. The detailed process and possible mechanisms for PL and TL are studied and discussed. For the variable concentration of Eu3+ on PL studies the PL intensity increases with increasing the concentration of dopant and the concentration quenching found after 2mol% of Eu3+ the optimized concentration was 2mol%, which is suitable for the display device application. In TL glow curve the optimized concentration was 1mol% for the UV irradiated sample and 0.2mol% of Eu3+ for the gamma irradiated sample and beta irradiated sample for 10 Gy dose. The kinetic parameters were calculated by the computerized glow curve deconvolution (CGCD) technique.