Characterization and dye sensitized solar cell performance of TiO2/ZnO nanocomposite structures synthesized at different concentrations

In this thesis, TiO2 nanotube/ZnO nanorod hybrid nanocomposite (ZTN) photoanodes were synthesized characterized. Also, dye-sensitized solar cells (DSSCs) performances of ZTN photoanodes were investigated. The self-organized and high ordered TiO2 nanotube arrays were growth by anodic oxidation on titanium foil. Then, TiO2 nanotube arrays were decorated by ZnO nanorods by hydrothermal method. ZTN photoanodes were characterized using by FESEM, XRD, AFM and XPS measurements. The characterization results showed that the crystal structure, morphology, elemental composition and density of ZnO nanorods on the surface of TiO2 nanotubes are very sensitive to ZnO precursor concentrations. The effect of ZnO precursor concentration on the photovoltaic performance of DSSC based on ZTN photoanodes was investigated by J-V and EIS measurements. It is concluded that, the highest DSSC efficiency of ZTN photoanode was measured 1.8% for precursor concentration of 60 mM which was more than double compared to DSSC based on bare-TiO2 nanotubes (0.8%). The improvement of DSSC efficiency originates from suppressing the recombination rate and decreasing the charge transfer resistance due to synergetic effect between TiO2 nanotubes and ZnO nanorods.