Photoelectrochemical studies of an ion conducting polymer (PEO)/semiconductor (Si) junction

The photoelectrochemical behaviour of a solid electrolyte/semiconductor (Si) junction is reported. The solid electrolyte him used is a recently developed proton conducting polymer electrolyte PEO-complexed with NH4ClO4 or NH4I which was either solution or spin cast. The best photo-conversion efficiency was obtained for PEO:NH4I in which excess iodine was added to give the redox couple I-2/2I(-). The optical micrographic studies of the interface showed a rubbery web-like morphology of the polymer which reduces the effective electrode/polymer electrolyte contact area (and hence leads to a smaller photoconversion efficiency).