Highly conductive transparent Al-doped zinc oxide （AZO） films with highly （002）-preferred orientation were successfully deposited on glass substrates at room temperature by RF magnetron sputtering. Optimization of deposition parameters was based on sputtering RF power and Ar pressure in the vacuum chamber. AZO films of 180nm with an electrical resistivity as low as 2.68 × 10^-3 Ω· cm and an average optical transmission of 90% in the visible range were obtained at RF power of 250W and Ar pressure of 1.2Pa. The effect of chemisorption of oxygen on the grain boundary would capture electrons from conduction band and lead the formation of potential barriers among the crystallites,which will influence the electric property of the AZO thin films. The films have satisfactory properties of low resistance and high transmittance for application as transparent conductive electrodes in light emitting diodes （LEDs） and solar cells.
