Preparation and photoelectrical property of the TiO2-ZnO nanorod-nanosheet hierarchical structure.

A new hierarchical structure of TiO₂-ZnO nanorod-nanosheet was prepared by two-step hydrothermal method without any seed layers. A spin-coating assisted successive ionic layer reaction method (SC-SILR) was used to deposit the CdS nanocrystals into the TiO₂ nanorod array and the TiO₂-ZnO hierarchical nanostructure to form the CdS/TiO₂ and CdS/TiO₂-ZnO nanocomposite films. Different analysis methods, such as SEM, TEM, XRD, UV-Vis and transient photocurrent, were utilized to characterize the morphologies, structures of the samples and investigate the light absorption properties, the photoelectric conversion performance of the electrodes. The results indicated that the transient photocurrent of the TiO₂-ZnO hierarchical nanostructure film was apparently superior to the TiO₂ nanorod array film after depositing the photosensitive layer of CdS and showed an evident enhancement at wavelength of 500 nm. Hybrid solar cells were assembled using P3HT as p- type polymer materials. Photovoltaic measurement results indicated that the energy conversion efficiency of the hybrid solar cell based on the hierarchical structure of P3HT/CdS/TiO₂-ZnO composite film could reach 0.65%, which revealed an increasing of 58% compared with that of the hybrid solar cell based on the P3HT/CdS/ TiO₂ composite film. [ABSTRACT FROM AUTHOR]