Polyacrylonitrile polymer electrolyte based photoelectrochemical cells have been fabricated with ruthenium bipyridyl complex as the sensitizer using porous films of SnO2/ZnO composite and also TiO2 films. The redox component of the electrolyte is XI + I-2, where X+ = Cs+, K+, Na+, Li+, or tetrabutylammonium ion. For both types of cells (SnO2/ZnO and TiO2) highest short-circuit photocurrents and efficiencies are obtained when X = Cs and in all cases these parameters were higher for the cells made from SnOz/ZnO. Results are explained as originating from the dependence of the mobility of I- in the polymer electrolyte on nature of the cation X+ and the necessity of wide separation of photogenerated electron and the resulting dye cation to overcome the diffusion-controlled kinetics of I- transport.