CuInSe2 (CIS) films have been prepared by one-step electrodeposition technique. The effect of thermal treatment in vacuum and under selenium vapour pressure on the composition and structure of CIS electrodeposited layers has been investigated. The structure and composition of these samples have been investigated by SEM, XRD, EDX and Raman spectroscopy. It was found that recrystallization of CIS thin film occurs with segregation of Cu-Se phases onto the bottom of films and formation of CIS grains different by size and composition. (c) 2007 Elsevier B.V. All rights reserved.