Investigation of the effect of reaction parameters on the microwave-assisted hydrothermal synthesis of hierarchical jasmine-flower-like ZnO nanostructures for dye-sensitized solar cells

Abstract

A facile, energy-efficient microwave assisted hydrothermal (MW-HT) method has been demonstrated to synthesize hierarchical jasmine-flower-like ZnO nanostructures. The obtained product was characterized using structural, morphological and optical studies by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Raman spectroscopy, photoluminescence spectroscopy (PL) and UV-visible spectroscopy. The obtained results revealed that nanostructured ZnO possesses good crystalline properties and enhanced scattering ability. The nucleation and crystal growth mechanism for the synthesized ZnO has been investigated by changing the reaction parameters such as microwave power, reaction time and temperature. A systematic investigation has also been carried out on the influence of the reaction parameters upon the photovoltaic performance of fabricated ZnO-based dye sensitized solar cells (DSSCs). It has been observed that ZnO nanostructures prepared in the microwave assisted power mode (300 W at 10 min) exhibited a maximum power conversion efficiency (PCE) of 4.12%, which is significantly higher than that of commercially purchased ZnO with a PCE of 1.08%. This could be attributed to the unique hierarchical jasmine-flower-like morphological features of the ZnO nanostructures prepared using a rapid MW-HT method.