Calcium sulphate phosphors activated with samarium as an impurity with various percentage composition have been prepared and their fluorescence rise and phosphorescence decay behaviours have been studied. The growth curve is investigated to study the density of traps. The process of filling of traps during x-ray excitation is revealed. The decay curves are analysed to study the distribution of traps, the nature of decay and kinetics involved in the luminescence process. The concentration dependence of fluorescence emission of the phosphors is also discussed.

CaSO₄ phosphors activated with Sm³⁺ impurity in varying concentrations have been prepared and their electroluminescence systematically studied. The voltage and frequency dependence of brightness is discussed and conclusions are drawn regarding the possible mechanism involved in the process.