Tungsten Doped Indium Oxide Thin Films Deposited at Room Temperature by Radio Frequency Magnetron Sputtering

Tungsten doped indium oxide （IWO） thin films were deposited on glass substrate at room temperature by radio frequency reactive magnetron sputtering. Chemical states analysis was carried out, indicating that valence states of element W in the films were W4＋ and W6＋. The effects of sputtering power and film thickness on the surface morphology, optical and electrical properties of IWO thin films were investigated. The IWO thin films had high transmittance in near infrared （NIR） spectral range. The resistivity, carrier mobility and carrier concentration owned their respective optimum values as sputtering power and thickness changed. The asdeposited IWO film with the minimum resistivity of 3.23 × 10^-4 Ω cm was obtained at a sputtering power of 50 W, with carrier mobility of 27.1 cm2 V-1 s-1, carrier concentration of 7.15 × 10^20 cm-3, average transmittance about 80% in visible region and above 75% in NIR region. It may meet the application requirement of high conductivity and transparency in NIR wavelength region.