Deposition and Application of Indium-Tin-Oxide Films for Defrosting Windscreens

The plasma-activated reactive evaporation technique was used for the formation of indium-tin-oxide (ITO) films. The ITO films were deposited on a heated (up to 350 °C) glass substrates using various mass ratios of indium and tin. The optical and electrical properties of the deposited ITO films were determined. The influence of the indium-to-tin mass ratio on the optical transmittance, bandgap, resistivity and resistance of ITO films was investigated. The bandgap of ITO films was increased from 3.18 to 3.37 eV, and the MIn/MSn ratio increased from 4.25 to 10.00. The average values of optical transmittance at the visible light wavelengths increased from ~43% to ~64% as tin mass was reduced. We demonstrated that ITO films with low resistivity ranging from 7.4 × 10−3 to 43.7 × 10−3 Ω·cm were obtained, and the MIn/MSn ratio changed from 4.25 to 10.00. The ITO film formed at the 9.25 MIn/MSn ratio demonstrated high transparency, a wide bandgap and optimal resistivity and resistance values. The heating characteristics indicated that the frozen ice on the ITO films was completely removed after 30 s when the applied voltage was 24 V.