Transparent conducting aluminum-doped zinc oxide (AZO) films have been prepared on glass substrates by radio frequency magnetron sputtering using a hydrogen-argon gas mixture at room temperature. The effect of hydrogen partial pressure on the optical and electrical properties of AZO films is investigated. The hydrogen partial pressure was varied from 0 to 1.25 x 10(-3) Pa during film growth. Polycrystalline Al-doped ZnO films having a preferred orientation with the c-axis perpendicular to the substrate were obtained with a root mean square roughness of similar to 2 nm. At an optimal condition, the AZO films with a resistivity of 5.1 x 10(-4) Q cm and an optical transparency of over 83% in the visible wavelength region are achieved. The AZO films with desired properties were used as an anode contact in polymeric electroluminescent devices and the electroluminescence performance of these OLEDs was studied. (c) 2005 Elsevier B.V. All rights reserved.