Effect of rf-power density on the resistivity of Ga-doped ZnO film deposited by rf-magnetron sputter deposition technique

Gallium-doped zinc oxide (GZO) films were studied using rf-magnetron sputter deposition technique for the use of transparent conducting oxide film. The effects of deposition parameters such as pressure, rf-power, and film thickness on electrical and optical characteristics of GZO films were evaluated to obtain transparent conducting film with high transmittance and low resistivity for a-Si:H thin film solar cells. The resistivity and the structural properties of GZO film strongly depended on rf-power density and film thickness. The 1200 nm-thick GZO film deposited at 15 mTorr and 150 °C with rf-power density of 4.46 W/cm2 showed the resistivity as low as 6.2 × 10−4 Ω cm and the average transmittance of 86.5% in visible light wavelength region of 400–800 nm.