Electrochemical deposition of Fe-S-O thin films

FeSxOy thin films were fabricated by the electrochemical deposition method on indium-tin-oxide (ITO)-coated glass substrates. FeSxOy is an environment-friendly material and is expected to have properties suitable for photovoltaics. The deposition solution contained FeSO4 and Na2S2O3. At 40 °C, a compact black film 0.5 μm in thickness with Fe:S:O composition 1:1:1 was deposited in 5 min on ITO substrate from a solution containing 40 mM FeSO4 and 100 mM Na2S2O3 at a pH 5.6 (inherent). In the photoelectrochemical measurement, the deposited FeSxOy film showed p-type conduction and photoconductivity. A ZnO/FeSxOy heterostructure was fabricated, and rectification properties were confirmed.