Studies of the adsorption process of Ru complexes in nanoporous ZnO electrodes

Nanostructured ZnO films consisting of 150-nm sized particles were dye-sens itized with different ruthenium complexes. Incident photon-to-current conve rsion efficiencies (IPCE) were found to be dependent on dye concentration a nd on residence time of the ZnO film in the dye solution. Results obtained using infrared and Raman spectroscopies together with traditional two-elect rode measurements using a sandwich-type cell gave evidence of dye agglomera tion in the nanostructured ZnO film. Possible reasons for the agglomeration process in ZnO films are discussed.