CuI has been synthesized at room temperature on Cu-tape/n-CulnS, by using the SILAR technique (successive ionic layer adsorption and reaction). The influence of wet chemical iodine treatment on the Cut has been investigated in more detail. The films were characterized by Xray diffraction (XPD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), elastic recoil detection analysis (ERDA) and surface photovoltage (SPV) techniques. The Cut films contain the gamma-phase of the Zinkblende structure. The crystallites are preferentially oriented in the (111) direction. After wet chemical iodine treatment, the fibrous surface morphology changed to a more dense Cut film with larger crystallites. Oxides could not be detected on the CuI surface. The density of surface states of CIS decreased after the CuI deposition. The importance of the wet chemical iodine treatment for the performance of Cu-tape/n-Cu-InS2/p-CuI solar cells has been demonstrated. (c) 2004 Elsevier B.V. All rights reserved.