Low-temperature growth and dye-sensitized solar cells applications of flower-shaped ZnO hexagonal nanorods.

Flower-shaped ZnO structures composed of hexagonal nanorods were grown in a large-quantity via simple aqueous solution process by using zinc nitrate as a source of zinc ions at low-temperature of approximately 85 degrees C. The as-grown flower-shaped ZnO structures composed of hexagonal nanorods were characterized in terms of their structural, optical and photovoltaic properties by using X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) pattern, FTIR, UV-Vis and Raman-scattering spectroscopy. The detailed structural investigations confirmed that the as-synthesized products are well-crystalline and possessing wurtzite hexagonal phase. For the application point of view, the as-grown flower-shaped ZnO structures composed of hexagonal nanorods were used as photo-anode materials to fabricate the dye sensitized solar cells (DSSCs). An overall light to electricity conversion efficiency of 1.1% with a short-circuit current of 4.34 mA/cm2, open-circuit voltage of 0.554 V and fill factor of 0.45, were achieved for the fabricated solar cell based on flower-shaped ZnO structures composed of hexagonal nanorods.