Investigation of various nano-structural morphologies of zinc oxide for their applications in dye-sensitized solar cells

In the current study, various morphologies of zinc oxide (ZnO) including nanorods, nanoflowers, nanosheets/flakes, nanospherical particles, nanohexagonal sheets, and nanoneedles have been prepared by using single step and two-step hydrothermal processes with optimized parameters such as growth temperature, growth time and compositions of both the seed and growth solutions. Fluorine doped tin oxide (FTO) coated glass was used as the substrate. The prepared morphologies were characterized with the help of scanning electron microscopy (SEM) and the purity of nanostructures was confirmed by elemental analysis (EDX). These nanostructures were used as photo-anode material to fabricate the DSSC using a dye (Rhodamine B) for enhancing the range of solar spectrum that is to be adsorbed. Finally the fabricated solar cells were characterized in terms of their efficiency, gauged by their fill factor. Among different morphologies investigated as photo anode materials; nanosheets/flakes were found to be showing maximum efficiency, with fill factor values around 0.5 due to their larger surface area, better porosity and enhanced capability of light trapping and scattering. (author)