Effect of exposure to optical radiation and temperature on the electrical and optical properties of In$_2$O$_3$ films produced by autowave oxidation

Indium-oxide films are synthesized by the autowave-oxidation reaction. It is shown that, upon exposure to optical radiation, the resistance of the films sharply decreases and the maximal relative change in the resistance is 52% at room temperature. Two resistance relaxation rates after termination of the irradiation, 15 $\Omega$ s$^{-1}$ during the first 30 s and 7 $\Omega$ s$^{-1}$ over the remaining time, are determined. The data of infrared spectroscopy of the films show that exposure to optical radiation induces a 2.4% decrease in the transmittance at a wavelength of 6.3 $\mu$m. It is found that, after termination of the irradiation, the transmittance gradually increases with a rate of 0.006% s$^{-1}$. It is suggested that photoreduction is the dominant mechanism responsible for changes in the electrical and optical properties of the In$_2$O$_3$ films.