Using a highly conductive ZnO(ZnAl2O4) ceramic target, c-axis-oriented transparent conductive ZnO:Al2O3 (ZAO) thin films were prepared on glass sheet substrates. by direct current planar magnetron sputtering. The structural, electrical and optical properties of the films (deposited at different temperatures and annealed at 400degreesC in vacuum) were characterized with several techniques. The experimental results show that the electrical resistivity of films deposited at 320degreesC is 2.67 x 10(-4) Omega cm and can be further reduced to as low as 1.5 x 10(-4) Omega cm by annealing at 400degreesC for 2 h in a vacuum pressure of 10(-5) Torr. ZAO thin films deposited at room temperature have flaky crystallites with an average grain size of similar to 100 nm; however those deposited at 320degreesC have tetrahedron grains with an average grain size of 150 nm. By increasing the deposition temperature or the post-deposition vacuum annealing, the carrier concentration of ZAO thin films increases, and the absorption edge in the transmission spectra shifts toward the shorter wavelength side (blue shift). (C) 2002 Elsevier Science B.V. All rights reserved.