This paper presents new advances on an atmospheric-based deposition process for Cu(ln,Ga)Se-2 synthesis, consisting of the electrodeposition of a Cu-In-Ga mixed oxide/hydroxide layer from an aqueous solution, at room temperature, followed by a thermochemical reduction and selenization. This process enables the one-step co-deposition of the three elements, from a simple aqueous electrolyte containing nitrate ions as oxygen precursor, with fast growing rates and precise control of composition. The reduction process is carried out thermally in pure hydrogen atmosphere and leads to Cu-In-Ga metallic alloys. After selenization, Cu(ln,Ga)Se2 phase was obtained and completed solar devices reach a 12.4% maximal power conversion efficiency. (C) 2013 Elsevier B.V. All rights reserved.