ZnO:AI thin films were deposited on glass substrates by RF magnetron sputtering from a powder compacted ceramic target. Structural, electrical and optical properties of the films with different thickness were characterized. The damp heat stability of ZnO:Al thin film was investigated for its application in thin-film solar cells. After the 1000 h damp heat treatment in harsh conditions of 85% relative humidity at 85 degrees C for all samples, a degradation of electrical properties was observed, while the transmissions of the films were almost unchanged. Thick films with a relative large grain size could form compact structure to resist the corrosion by oxygen and water molecules. (c) 2007 Elsevier B.V. All rights reserved.