Thermoluminescence studies of CaS : Bi nanocrystalline phosphors

The thermoluminescence (TL) studies of CaS : Bi nanocrystalline phosphors prepared by the wet chemical co-precipitation method and exposed to γ-rays have been discussed. The average grain size of the samples was estimated as 35 nm using Scherrer's equation. The samples exhibit a complex TL glow curve with multiple peaks. Sample exposed to γ-rays showed that the TL intensity increases linearly as the radiation doses increased in the 1.012–40.48 mGy range. The trap parameters namely, activation energy ( E ), order of kinetics ( b ) and frequency factor ( s ) of the main peaks of the CaS : Bi(0.08 mole%) sample have been determined using Chen's method. The effect of different dopant concentrations and different heating rates has also been discussed.