Characterization and dye sensitized solar cell performance of TiO2 / ZnO nanocomposi̇te structures synthesi̇zed at different temparatures

In this thesis, TiO2 nanotube / ZnO nanoparticle nanocomposite (TZN) photoanodes were synthesized, characterized and combined as dye-sensitized solar cells (DSSC) at optimum conditions to increase photovoltaic efficiency. TiO2 nanotube arrays (TNA) were grown on titanium foil by anodic oxidation method and were used as a substrate in ZnO decoration process by hydrothermal method. Hydrothermal temperature values have been changed to determine the optimum ZnO decoration density in order to achieve higher photo-conversion activity. Surface morphology, elemental composition, and characterization of TiO2 nanotube / ZnO nanoscale hybrid nanocomposite (TZN) structures were performed by using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectric spectroscopy (XPS). While the efficiency of DSSCs produced with TiO2 nanotubes was measured as 0.81%, the highest DSSC efficiency based on TZN photoanode reaches as 1.67% at 130 C with a temperature higher than two times. This increase in BDGP efficiency is due to the reduction of the recombination rate and the reduction in charge transfer resistance due to the synergistic effect between the TiO2 nanotubes and the ZnO nanoparticles.