Conversion of light to electrical energy by CdS PEC cells

In the present conversion processes of the photoelectrochemical (PEC) CdS/electrolyte/Pt cells have been studied. Polycrystalline CdS anodes were prepared by pyrolytic spraying and chemical deposition. A "white light" conversion efficiency of 0, 4 % during a few days of operation was obtained with K3Fe(CN)6/K4Fe(CN)6 redox system, but for a more stable cell in a Na2S/S electrolyte an efficiency of 0, 01 % was found. The less efficient (0, 05 %) PEC cell with Q/H2Q redox couple showed the unchanged conversion properties for longer periods of time.The changes of U_oc with redox electrolyte Fermi levels were measured and discussed. The value of the flat band potential was determined from the analyses of the photocurrent vs. potential characteristics.