CuO/CuWO4 p-n junction thin films were prepared by using electrodeposited Cu films with an acidic cupric lactate system (pH <= 5). The photoelectrochemical properties of CuO and CuWO4-CuO films were studied by photoresponse and current-potential characteristics under 1 sun illumination. The photocurrent of CuO films prepared by annealing Cu films electrodeposited at pH 5 is about 0.6 mA/cm(2) at -0.6 V vs Ag/AgCl. Both p-type and n-type behaviors occurred on CuO-CuWO4 film in the potential range from 0.8 V to -0.6 V vs Ag/AgCl. The photoelectrochemical photocurrent switching (PEPS) effect was observed in the case of p-CuO/n-CuWO4 heterojunction and the photocurrent switching potential is +0.33 V vs Ag/AgCl. (C) 2012 Elsevier Ltd. All rights reserved.