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 x 10(-4) Wa 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 CuInSc2 semiconductor films were prepared by electrodeposition over SnO2 conducting-coated glass substrates. The best result to avoid CuInSc2 degradation and to have photoelectrochemical response was obtained with the 40-mu-thick ruthenium films. The photocurrent response was obtained in a 0.5 M sulfuric acid solution at 291 K.