Sponge-like ZnO nanostructures by low temperature water vapor-oxidation method as dye-sensitized solar cell photoanodes

In this manuscript a low temperature oxidation process to convert zinc nanostructures into ZnO preserving the nanomorphology is presented. This method involves the exposure of sputtered porous metal films to water vapor flow in ambient atmosphere and near to room temperature. The converted material was investigated by morphologic, stoichiometric and crystallographic characterizations revealing the formation of spongy ZnO nanostructures in wurzite phase. Water vapor-oxidized samples were integrated as dye-sensitized solar cell photoanodes and characterized by I–V electrical and electrochemical impedance spectroscopy and the results compared with thermally treated electrodes. The obtained photovoltaic parameters confirm the highly promising properties of this material as low-temperature processed dye-sensitized solar cell photoanode.