Transparent conductive AI-doped zinc oxide (AZO) thin films were prepared by a sol-gel method and their structural, electrical and optical properties were systematically investigated. A minimum resistivity of 4.2 x 10(-3) ohm cm was obtained for the 650 degrees C-annealed films doped with 1.0 at.% Al. All films had the preferential c-axis oriented texture according to the X-ray diffraction (XRD) results. Optical transmittance spectra of the films showed a high transmittance of over 85% in the visible region and the optical band gap of the AZO films broadened with increasing doping concentration. (C) 2008 Elsevier B.V. All rights reserved.