The structural, morphological, compositional and photoelectrochemical properties of co-electrodeposited and selenized CIS thin films were characterized using various techniques. As-deposited as well as selenized films exhibited a compact or a granular morphology depending on the composition. The film stoichiometry was improved after selenization at 550 degrees C in a tubular furnace, The film conductivity type, carrier concentration and flat-band potential were determined from the photoelectrochemical studies. The films are formed with a mixed composition of the binary as well as the ternary phases. From the results of these studies, a model is suggested for the superficial as well as the bulk conductivity types of the film.