A tandem photovoltaic cell using a thin-film polymer electrolyte

A tandem photovoltaic cell has been fabricated using a thin-film plastic electrolyte to connect in optical and electrical series an n-type CdS thin-film and a p-type CdTe single crystal. The electrolyte was a thin film of poly(ethylene oxide) with a polysulfide redox couple. An open circuit voltage of 625 mV and a short-circuit current of 35 μA/cm2 were obtained under illumination of 100 mW/cm2 with a xenon lamp. The cell output in the present configuration is limited by the series resistance and insufficient band bending in the semiconductor electrodes due to unfavorable resistance matching of the components.