Protective rhutenium thin films on CuInSe₂ for hydrogen evolution in acidic media

Ruthenium thin films were prepared by metal organic chemical vapor deposition (MOCVD) on the surface of copper indium diselenide (CuInSe₂) semiconductor at a total pressure of 1.33 × 10^-4 MPa and temperatures as low as 448 K using ruthenium dodecarbonyl as precursor. In our knowledge the lowest temperature reported for the deposition of this element. This permitted to protect the surface of the CuInSe₂ semiconductor with crystalline, uniform and smooth ruthenium films. The CuInSe₂ semiconductor films were prepared by electrodeposition over SnO₂ conducting-coated glass substrates. The best result to avoid CuInSe₂ degradation and to have photoelectrochemical response was obtained with the 40-nm-thick ruthenium films. The photocurrent response was obtained in a 0.5 M sulfuric acid solution at 291 K.