Photovoltaic water electrolysis using the sputter-deposited a-Si/c-Si solar cells

The solar cell which is employed for photovoltaic water electrolysis was fabricated by sputter-depositing a-Si:H on Si wafer. The electrolysis was conducted by connecting the series-connected solar cell externally to the hydrogen and the oxygen evolution electrodes. The conversion efficiency of 3.0% from the solar to hydrogen chemical energy was obtained and can be expected to be improved further by optimizing the system.