PHOTOLUMINESCENCE, THERMOLUMINESCENCE AND OPTICALLY STIMULATED LUMINESCENCE STUDIES IN ZINC-BASED FLUOROPERVOSKITES.

The optically stimulated luminescence, thermoluminescence and photoluminescence in various Cu and Ag doped zinc based fluoropervoskites are studied. In all the samples, photoluminescence of Cu+ and Ag+ is observed which could be attributed to 3d94 s1←→3d10 and 4d95 s1←→5d10 transitions, respectively. The observed emission is double humped and the main emission band shifts to the lower wavelength side with increasing ionic size of the alkali ion. All the studied fluoropervoskites show reasonable OSL sensitivity. Highest sensitivity is observed for Cu doped ZnNaF3 and is 25% compared to commercial Al2O3:C. Weak thermoluminescence is observed in all samples. In all Ag doped samples the TL peak is observed at 200°C whereas for Cu doped samples peak is observed at 150°C, and correlated with the OSL. The samples show good linear dose response in the 10 mGy-1.2 Gy range and show good reusability characteristics. This study will lead to the development of zinc-based fluoropervoskite phosphors for the radiation dosimetry using OSL.