Effect of deposition time on the properties of Al doped ZnO films prepared by DC magnetron sputtering

Aluminum-doped zinc oxide (AZO) thin films were successfully prepared on glass substrates at room temperature by DC magnetron sputtering. The sputtering time varied from 5 minute to 30 minute, while the power was kept at 230W for all depositions. The structural and optical properties of AZO films were investigated by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Raman Spectroscopy, Photoluminescence, and UV–visible spectrophotometer. Polycrystalline AZO thin films with hexagonal wurtzite structure were recorded by XRD analysis. The crystallinity and surface morphologies of the films are strongly dependent on the growth time, which in turn exerts a great effect on structural and optical properties of the AZO films. The transmittance for all the AZO films was above 92% in the visible region, and the largest band gap achieved as compare to intrinsic ZnO (3.3 eV). The defect distribution was analyzed by PL analysis.