Cuprous oxide (Cu2O) thin films were deposited on Cu and tin oxide coated glass substrates through potentiostatic electrodeposition. The optimum range of deposition parameters was experimentally investigated. X-ray diffraction studies revealed the formation of single-phase cubic Cu2O films in the deposition potential range from -0.355 to -0.555 V versus SCE. Studies revealed that an optimum pH of 9.0 yielded single-phase cubic films with improved crystallinity. The preferential orientation of (200) cubic Cu2O peak was found to increase with bath temperature in the range 30-70 degrees C. The effects of annealing on the preferred orientation, grain size and optical band gap were studied. The energy conversion efficiencies of as-deposited and annealed p-Cu2O films as photocathodes in photoelectrochemical (PEC) solar cells were studied and the results were discussed. (c) 2004 Elsevier B.V. All rights reserved.