Transparent conducting oxides (TCOs) have a wide range of applications in several optoelectronic devices but beyond the conventional characteristics of transparency and conductivity different characteristics are required by each different technology. This constitutes a promising stimulation of the present research of TCO films. In order to investigate the possible application of antimony doped tin oxide (ATO) thin films as a TCO electrode for new concepts in solar cells and other optoelectronic devices, ATO thin films with adequate properties in terms of light transparency and conductivity were obtained using room temperature processes by oxygen-reactive DC magnetron sputtering, then the films were annealed in nitrogen atmosphere at a temperature of 350 degrees C. The effect of O-2/(Ar+O-2) ratio in the sputter flow gas mixture has been studied. Results regarding to optical and electrical properties, microstructure and composition measurements are reported. (C) 2009 Elsevier B.V. All rights reserved