Thermoluminescence and dosimetric properties of bismuth doped CaS nanocrystalline phosphor

The irradiation effect on bismuth doped CaS nanocrystalline phosphors and their possible applications to solid state dosimetry have been studied. The wet chemical co-precipitation method has been used for preparation of nanocrystallites. In UV exposed CaS nanocrystallites, the thermoluminescence glow curve consists of two peaks at 439 and 561 K. The effect of different concentrations, dose dependence, fading and reusability in CaS:Bi nanocrystallites have been investigated. The high temperature peak (dosimetric peak) intensity is nearly linear in a wide range of UV exposure. A blue shift has been observed in photoluminescence spectra, which may be attributed to quantum size effect.