ZnO Nanosheet-Nanowire morphology tuning for Dye-sensitized solar cell applications

Highlights: • Low temperature hydrothermal growth of several ZnO nanostructures. • ZnO nanosheet-nanowire morphology tuning by simply changing the NaOH concentration. • Dye-sensitized solar cells (DSSCs) were fabricated using nanowires and nanosheets. • Nanosheet based DSSCs showed improved J-V characteristics and charge dynamics. In this work, ZnO nanosheet-nanowire morphology tuning could be achieved by simply changing the NaOH concentration in a low-temperature chemical bath. Our method produces nano/microstructures ranging from nanorods/nanowires with a wide range of diameters (~20 nm-4 µm) and aspect ratios (~1–20) to nanosheets with different dimensions. Photoluminescence spectra were dominated by violet emission attributed to Zn interstitial related defects forming during the growth. Focusing on the specific surface area of the final product, 30–40 nm-thick nanosheets showed the best J-V performance and transport dynamics when implemented in dye-sensitized solar cells.