Thermoluminescence and kinetic analysis of Gamma irradiated Bi doped SrS nanocrystalline phosphors

Thermoluminescence (TL) of Bi doped SrS nanocrystalline phosphors exposed to Cs137 gamma (γ) radiations has been investigated. The TL glow curve of γ-irradiated SrS:Bi nanocrystallites consists of a glow maxima at 454 K with small shoulders around 375 K and 558 K. The effects of different dopant concentrations, heating rates and dose dependence on the TL glow curve have also been investigated. We have observed that the TL intensity increases with gamma dose, which may be explained on the basis of a high surface to volume ratio for the nanoparticles. These studies reveal that the 0.05 mol% of Bi3+ concentration is optimum for the maximum TL output. Further, the trapping parameters namely, activation energy (E), order of kinetics (b) and frequency factor (s) for SrS:Bi (0.05 mol%) have been determined using glow curve deconvolution (GCD) functions.