Temperature-dependant growth and properties of W-doped ZnO thin films deposited by reactive magnetron sputtering

W-doped ZnO (WZO) thin films for thin film solar cells have been deposited by pulsed direct-current reactive magnetron sputtering. The microstructures, surface morphologies, optical and electrical properties of WZO thin films are investigated at different substrate temperatures. The experimental results indicate that a proper substrate temperature is the key factor for fabricating high-quality WZO thin films. The surface roughness of WZO thin films increases firstly from 15.65 nm to 37.60 nm, and then decreases from 37.60 nm to 11.07 nm with the increase of substrate temperature. Higher Hall mobility deposited at the higher temperatures is attributed to the compact structure and good crystallization quality. The WZO thin film prepared at the temperature of 325 ℃ presents excellent optical and electrical properties with an average transmittance of 85.7% in the wavelength range from 400 nm to 1500 nm, a low resistivity of 9.25× 10-3 Ω·cm, a sheet resistance of 56.24 Ω /sq and a high Hall mobility of 11.8 cm2·V-1·s-1.