Photovoltaic activity in a ZnSe/PEO–chitosan blend electrolyte junction

Thin films of ZnSe and PEO–chitosan blend polymer doped with NH₄I and iodine crystals were prepared to form the two sides of a semiconductor electrolyte junction. ZnSe was electrodeposited on indium tin oxide (ITO) conducting glass. The polymer is a blend of 50 wt% chitosan and 50 wt% polyethylene oxide. The polymer blend was complexed with ammonium iodide (NH₄I), and some iodine crystals were added to the polymer–NH₄I solution to provide the I⁻/I³⁻redox couple. The room temperature ionic conductivity of the polymer electrolyte is 4.32 × 10⁻⁶ S/cm. The polymer film was sandwiched between the ZnSe semiconductor and an ITO glass to form a ZnSe/polymer electrolyte/ITO photovoltaic cell. The open circuit voltage (V _oc) of the fabricated cells ranges between 200 to 400 mV and the short circuit current between 7 to 10 μA.