In inorganic semiconductor (such as CdS)-sensitized solar cells, isolated nanoparticles (including quantum dots) or Porous semiconducting layers are particularly efficient and effective in extracting charge carriers generated by solar energy, without a serious recombination among sensitizers. In this study. porously structured CdS was formed by spray pyrolysis deposition (SPD) using an excess cadmium chloride and thiourea aqueous mixture solution onto an mp-TiO2 substrate pre-heated to 450 degrees C in an air atmosphere and subsequent washing of the excess cadmium chloride using deionized water. As expected, the power conversion efficiency of a photoelectrochemical solar cell fabricated with the porous CdS was greatly improved, to 1.71%, the highest efficiency ever reported for CdS-sensitized solar cells employing polysulfide as an electrolyte. This improvement in performance is attributed to the efficient transport of the charge carriers generated in CdS. (C) 2010 Elsevier Ltd. All rights reserved.