The photoelectrochemical properties of Copper Oxide thin film, prepared by spray pyrolysis on conducting glass (SnO2: F-coated glass) substrate were investigated as a function of film deposition temperature and spray time. The variation in the deposition temperature affected the film morphology. The film deposited at substrate temperature 350degreesC exhibited better photoresponse than the films prepared at 300degreesC and 400degreesC. Creation of large number of dislocations and kink sites at 300degreesC and 400degreesC, which act as a recombination center for photogenerated electron has been held as a possible cause for poor photoresponse observed. The rise in photocurrent density with increase in spray time has been attributed to the increase in film thickness, which is probably allowing the film to absorb photons more efficiently. X-ray diffraction patterns of films confirm the presence of cupric oxide (CuO) phase. The films of CuO were found of n-type, apparently suggesting the existence of oxygen vacancies in the structure, on account of incomplete oxidation taking place at a relatively low temperatures (300-400degreesC). (C) 2003 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.