Investigation of structural, optical, surface, electrochemical and corrosion properties of ZnO and AZO nanorod arrays for dye absorption applications

In dye-sensitized solar cells (DSSC), photoanodes have special importance in the processes of dye support, photon absorption and electron transport. ZnO nanorod arrays are promising photoanode materials, but their properties need to be improved by innovative fabrication approaches to improve the performance of ZnO-based DSSCs. In this study, pure and Al-doped ZnO (AZO) nanorod arrays were grown by hydrothermal method onto ZnO seed layers produced by sol-gel spin coating. As far as we know, for the first time in the literature, HMTA-HMDA ligand mixture was used instead of HMTA in the preparation of hydrothermal precursor solutions. To investigate the potential use of ZnO and AZO nanostructured films as photoanodes in DSSCs; their surface, structural and optical properties were examined. Additionally, charge transfer kinetics, corrosion resistance and dye loading capacities were determined by advanced analyzes such as electrochemical impedance spectroscopy, potentiodynamic polarization and adsorption-desorption methods. The supporting HMDA ligand and Al impurity used in the preparation of hydrothermal precursor solutions led potential usages as photoanode of ZnO nanorod arrays to increase by improving their structural, optical, surface, and electrochemical properties, corrosion resistance and dye loading capacities.