Clean and time-effective synthesis of anatase TiO₂ nanocrystalline by microwave-assisted solvothermal method for dye-sensitized solar cells

In this article, we report a clean and time-effective solvothermal synthesis route using microwave-assisted heating method to prepare nanocrystalline anatase TiO₂ with its application for dye-sensitized solar cells. With this proposed method, pure anatase TiO₂ nanoparticles with size about 20 nm are successfully obtained at 220 C for 30 min. Our method of microwave-assisted organic solvothermal route significantly reduces the elaborating process of washing and solvent exchange for the subsequent paste formation. The as-synthesized TiO₂ colloidal solution is ready for particle dispersion that markedly simplified the preparation procedures. Material characterizations of the anatase TiO ₂ nanoparticles are performed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), respectively. The photovoltaic performances of the dye-sensitized solar cells assembled with the as-synthesized TiO ₂ nanocrystallines as photoanodes in various film thicknesses are examined. An excellent energy conversion efficiency of 7.8% is achieved which is comparable to the previously reported dye-sensitized solar cells made of hydrothermal microwave-synthesized TiO₂.