The deposition of Cu(In,Ga)Se-2 (CIGS) thin films has been performed by one-step RF sputtering using a single quaternary target and followed by sulfurization to incorporate S into CIGS films. The effect of sulfurization temperature and time on the properties of the films was studied. The sulfurized Cu(In,Ga)(Se,S)(2) (CIGSeS) films show that the chalcopyrite peaks shifted to high diffraction angles and the CuS and InS second phases could be formed at low sulfurization temperature. These indicate possible incorporation of S into the films. The formation and disappearance of these second phases depended on the sulfurization temperature and time. The band gap increased with increasing sulfurization temperature and time because of the shift of the absorption edge due to the increase of S/(S+ Se) ratio. It was revealed that the resistivity of the as-deposited CIGS film increased after sulfurization while the carrier concentration and mobility decreased. It is believed that the sulfurization process of CIGS films can be utilized as a method to control the properties of the films. (C) 2014 Elsevier B. V. All rights reserved.