Controllable synthesis of hierarchical SnO2 microspheres for dye-sensitized solar cells

Three-dimensional hierarchical SnO2 microspheres were successfully synthesized through a rapid sonochemical reaction followed by a facile solvothermal process. The resultant samples were characterized in detail by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM). It was observed that the hierarchical SnO2 microspheres (similar to 2.2 mu m) consist of nanoparticles (similar to 23-30 nm). These samples are used to fabricate photoelectrodes for dye-sensitized solar cells (DSSCs). The effects of different samples on the photovoltaic performance were studied based on photocurrent-voltage (J-V), intensity-modulated photocurrent spectroscopy (IMPS) and intensity-modulated voltage spectroscopy (IMVS). It is found that the highest power conversion efficiency of 6.25% has been achieved based on the hierarchical SnO2 microspheres film photoanode with thickness of similar to 13.5 mu m, and the corresponding photovoltaic parameters are 14.11 mA cm(-2) in short-circuit current density, 803 mV in open-circuit voltage and 0.55 in fill factor, respectively. (C) 2015 Elsevier B.V. All rights reserved.