Growth of ZnO nanorods on TiO2 nanoparticles films and their application to the electrode of dye-sensitized solar cells

A ZnO nanorods (NRs)/TiO2 nanoparticles (NPs) film has been prepared by electrochemical deposition of ZnO NRs growth on P25 TiO2 NPs film surfaces. It was found that ZnO NRs/TiO2 NPs could significantly improve the efficiency of dye-sensitized solar cells owing to its relatively enhanced light-scattering capability and efficient charge transport efficiency. The overall energy-conversion efficiency (η) of 3.48 % was achieved by the formation of ZnO NRs/TiO2 NPs film, which is 33 % higher than that formed by TiO2 NPs alone (η = 2.62 %). The charge recombination behavior of cells was investigated by electrochemical impedance spectra, and the results showed that ZnO NRs/TiO2 NPs film has the longer electron lifetime than TiO2 NPs alone, which could facilitate the reduction of recombination processes and thus would promote the photocatalysis and solar cell performance.