FeS and FeS2 nanosheet films were selectively synthesized on iron substrates through one-step hydrothermal treatment of iron foil and sulfur powder in the presence or absence of hydrazine. The resulting FeSx (x = 1, 2) nanosheet films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) and used as novel photocathodes in tandem solar cells with dyesensitized TiO2 nanorod films as the corresponding photoanode. The photovoltaic properties of the tandem dye-sensitized solar cells were carefully studied. We found that the per...
