Characterization of a very low-cost silicon cathode-zinc electrolyte solar cell

This work presents implementation and characterization of a very low cost photo-electro-chemical (PEC) solar cell consisting of a p-type silicon photo-cathode and a zinc counter electrode immersed in a zinc (II) electrolyte. The cell operates based on the semiconductor-electrolyte junction eliminating the need for PN junction formation, hence providing a very low cost alternative for solar power generation. While photo corrosion is a serious issue for n-type silicon electrodes operating as photo-anodes, using p-type silicon acting as photo-cathode helps significantly reduce electrode corrosion and improve the electrode stability and lifetime. Output currents as high as 108 mA, voltages as high as 0.8V, and maximum power of 45.5mW have been measured for the p-Si/Zn photocell with 10cm² silicon electrode area (4.54% conversion efficiency). After running the cell for 180 hours under 1 sun illumination, only minimal electrode corrosion in isolated spots on the surface was observed.