Gamma radiation dosimetry using tellurium dioxide thin film structures

Thin films of tellurium dioxide (TeO₂) were investigated for γ-radiation dosimetry purposes. Samples were fabricated using thin film vapour deposition technique. Thin films of TeO₂ were exposed to a ⁶⁰Co γ-radiation source at a dose rate of 6 Gy/min at room temperature. Absorption spectra for TeO₂ films were recorded and the values of the optical band gap and energies of the localized states for as-deposited and γ-irradiated samples were calculated. It was found that the optical band gap values were decreased as the radiation dose was increased. Samples with electrical contacts having a planar structure showed a linear increase in current values with the increase in radiation dose up to a certain dose level. The observed changes in both the optical and the electrical properties suggest that TeO₂ thin film may be considered as an effective material for room temperature real time γ-radiation dosimetry.