Influence of total absorbed dose of gamma radiation on optical bandgap and structural properties of Mg-doped zinc oxide

High energy photon of gamma radiation interacts with matter and alter physical properties of materials. Optoelectronic and photonic devices, which are placed at space satellite and near radiation source like a nuclear reactor, can be exposed to gamma radiation. Effect of gamma radiation must be investigated before applying a material in a high radiation environment. In this paper, a potential material for optoelectronics and photonic devices, Mg-doped ZnO thin film of 200 nm was fabricated on a glass slide by sol-gel spin-coating method and irradiated with 579.96 Giga gamma photons per second per centimeter square surface area by Co-60 gamma source. Effect of absorbed dose on Mg-doped ZnO thin film was investigated for the first time. Variation of surface morphology, optical properties, and lattice parameters, caused by gamma radiation absorption doses in the range of 0 kGy-100 kGy, was assessed. It is observed that surface morphology is changed significantly with absorbed dose. With non-linear and monotonic fashion, dislocation density and lattice strain tend to increase, whereas crystallite size and bandgap tend to decrease with absorbed dose. Transmittance and absorbance spectra are changed considerably as well.