The effects of 200-MeV Ag^{ +15} ion irradiation on the optical properties of TiO_{ 2} and SnO_{ 2} thin films prepared by using the RF magnetron sputtering technique were investigated. These films were characterized by using UV-vis spectroscopy, and with increasing irradiation fluence, the transmittance for the TiO_{ 2} films was observed to increase systematically while that for SnO_{ 2} was observed to decrease. Absorption spectra of the irradiated samples showed minor changes in the indirect bandgap from 3.44 to 3.59 eV with increasing irradiation fluence for TiO_{ 2} while significant changes in the direct bandgap from 3.92 to 3.6 eV were observed for SnO_{ 2}. The observed modifications in the optical properties of both the TiO_{ 2} and the SnO_{ 2} systems with irradiation can be attributed to controlled structural disorder/defects in the system.
Categories: cond-mat.mtrl-sci physics.acc-ph