Preparation and properties of tungsten-doped indium oxide thin films

Tungsten-doped indium oxide (IWO) thin films were deposited on glass substrate by DC reactive magnetron sputtering. The effects of sputtering power and growth temperature on the structure, surface morphology, optical and electrical properties of IWO thin films were investigated. The thickness and surface morphology of the films are both closely dependent on the sputtering power and the substrate temperature. The transparency of the films decreases with the increase of the sputtering power but is not seriously influenced by substrate temperature. All the IWO thin film samples have high transmittance in near-infrared spectral range. With either the sputtering power or the growth temperature increases, the resistivity of the film decreases at the beginning and increases after the optimum parameters. The as-deposited IWO films with minimum resistivity of 6.4×10⁻⁴ Ω·cm were obtained at a growth temperature of 225 °C and sputtering power of 40 W, with carrier mobility of 33.0 cm²·V⁻¹·s⁻¹ and carrier concentration of 2.8×10²⁰ cm⁻¹ and the average transmittance of about 81% in near-infrared region and about 87% in visible region.