Single-layered Cu-In-Ga-Se precursors were fabricated by one-step sputtering of a single quaternary Cu(In,Ga)Se2 (CIGS) chalcogenide target at room temperature, followed by post selenization using Se vapor obtained from elemental Se pellets. The morphological and structural properties of both as-deposited and selenized films were characterized by X-ray diffraction (XRD), Raman spectroscope and scanning electron microscope (SEM). The precursor films exhibited a chalcopyrite structure with a preferential orientation in the (112) direction. The post-selenization process at high-temperature significantly improved the quality of the chalcopyrite CIGS. The CIGS layers after post-selenization were used to fabricate solar cells. The solar cell had an open-circuit voltage Voc of 0.422 V, a short-circuit current density J = 24.75 mA, a fill factor of 53.29%, and an efficiency of 7.95%. Copyright © 2010 John Wiley & Sons, Ltd.