MnO/TeO/sub 2/ thin films as optical gamma radiation sensors

Abstract

This work investigates the effects of /spl gamma/-rays on the optical properties of pure and mixed oxide materials, namely MnO and TeO/sub 2/, for their possible application as thin film optical gamma radiation sensors. The values of the optical band gap E/sub opt/ were obtained in view of the Mott and Davis theory. All samples showed a decrease in E/sub opt/ with an increase in radiation dose to a certain level, which was found to be composition-dependent. Films with 100 wt.% MnO exhibited the highest sensitivity to low doses of radiation, showing a strong decline in the optical band gap value from 0.64 eV before irradiation to 0.54 eV after a dose of 1.14 mSv. It was experimentally confirmed that both the sensitivity and the working dose range of radiation sensors can be controlled by the composition of the materials used.