Robust Stability of Optical and Electronic Properties of Gallium-Doped Zinc Oxide Thin Films to Gamma Ray Irradiation

Through combined measurements of broadband optical spectroscopy (10 meV to 6 eV), electrical resistivity, and Hall effect, the effects of gamma ray irradiation on electronic and optical properties of gallium-doped ZnO (GZO) thin films, deposited by ion plating direct-current arc discharge, are investigated. A significant number of films, deposited at various discharge currents (I _D = 100–200 A) and oxygen gas flow rates (OFR = 0–25 sccm), exposed to doses of 15 and 30 kGy of gamma rays, are studied. The results indicate strong resilience of films to irradiation: visible range transparency is reduced by 10–12% and the optical bandgap shifts to lower energies by less than 3%, while electrical resistivity, carrier concentration, and electron mobility remain nearly unchanged.