Growth, properties and dye-sensitized solar cells (DSSCs) applications of ZnO nanocones and small nanorods

Crystalline ZnO nanocones (NCs) and small nanorods (SNRs) were synthesized via facile aqueous solution process at low-temperature of 80±5 °C. The synthesized ZnO nanostructures were characterized in detail in terms of their morphological, structural, optical and photovoltaic properties. The morphological investigations of as-synthesized nanostructures were performed by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) which confirms the formation of ZnO nanocones and nanorods in large quantity. The structural and compositional properties of as-synthesized ZnO nanostructures were evaluated by X-ray diffraction (XRD) pattern, energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy and Raman-scattering spectroscopy techniques. The studies revealed the well-defined crystalline and pure phase ZnO for as-grown nanostructures. UV-Vis spectroscopy was used to determine the optical properties of as-synthesized ZnO nanostructures. The as-synthesized ZnO NCs and SNRs were used as anode materials for the fabrication of dye-sensitized solar cells (DSSCs). The fabricated DSSCs using ZnO NCs and SNRs exhibited overall light-to-electricity conversion efficiencies of ~0.91% and 0.64%, open-circuit currents (V _OC) of 0.703 V and 0.650 V, short-circuit currents (J _SC) of ~2.29 mA/cm ² and ~1.46 mA/cm ² and fill factors (FF) of 0.55 and 0.67, respectively.