Optimization of ZnO doped TiO2 nanopillars as photoanode for dye sensitized solar cells

Abstract Recent advances in nanotechnology have contributed to the development of engineered nanoscale materials as innovative prototypes to be used for various applications due to their unique features, including a large surface area, structural and optical properties. The introduction of low-cost, high-efficiency Dye Sensitized Solar Cells (DSSCs) have emerged as a potential alternative to the conventional thin film solar cells. In this work, hierarchical nanopillar layers of ZnO/TiO2 grown on TiO2 seed layer were synthesized successfully using a simple and cost- effective Spin coating and Hydrothermal methods. The synthesized sample was characterized by XRD, HR-SEM, UV-DRS, BET and Photoconductivity analysis. The XRD analysis reveals the structure and crystalline nature of the synthesized samples and the crystallite size was found to be 83 nm. The morphology and the average particle size of the synthesized sample were examined by the HR-SEM analysis from which the value was estimated to be 84 nm. UV-DRS analysis gives the absorbance spectrum of the sample in which the absorbance peak is located at 203 nm. Kubelka-Munk function was used to calculate the optical band gap which was found to be 2.7 eV. BET analysis indicates that the specific surface area of the sample with 25.29 m2/g and the field dependent dark and photoconductivity studies recorded greater conductivity owing to factors such as higher surface area and good optical studies. These results strongly suggest that the synthesized sample would be a promising material for solar cell applications especially as photoanode in DSSCs.