Thermoluminescence characteristics of CaS doped with rare earth ions Ce and Sm

CaS:Ce, Sm nanophosphors have been synthesized using solid state diffusion method with an aim to study the thermoluminescence characteristics of CaS:Ce,Sm system with varying concentrations of cerium and smarium in CaS host. The structural characterization of nanophosphors was done using XRD and TEM spectroscopy. We have investigated the effect of different concentrations of cerium and smarium in CaS host on the TL intensity. TL intensity is found to be maximum for CaS:Ce0.4Sm0.6. The effect of different heating rates on the TL glow curves recorded after a UV exposure of 560 mJ/cm2 has been investigated. Peak of the TL glow curve shifts toward higher temperature as the heating rate increases and the TL intensity decreases. Effect of different doses of UV on the TL glow curve of CaS:Ce0.4Sm0.6 at a heating rate of 10 K/s has been studied and all the glow curves show a single peak around 440 K. With increasing dose the TL intensity increases linearly upto 560 mJ/cm2 of the dose and afterward saturation region is obtained upto 13.5 J/cm2. Beyond it a fall is recorded upto 80 J/cm2 of the exposure. Analysis of the TL glow curve and calculation of the trapping parameters has been done with the help of Glow curve deconvolution software.