Dye-sensitized solar cells made from BaTiO3-coated TiO2 nanoporous electrodes

We reported on the preparation of a thin BaTiO3-coated layer (∼2.27 nm) on the surface of TiO2 and its further application in the dye-sensitized solar cells (DSCs). The as-prepared BaTiO3–TiO2 films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscope (TEM). The performances of the DSCs with and without BaTiO3 coating were analyzed by cyclic voltammograms (CVs), electrochemical impedance spectroscopy (EIS), and current–voltage measurements. It was found that the BaTiO3–TiO2 films with about 12 μm thickness increased the dye adsorption, resulting in increased Jsc. In the meantime, the BaTiO3 modification on the TiO2 surface is beneficial to the formation of an energy barrier against the electron transfer from TiO2 to I3−, providing the increase of Voc due to the increased electron density in the TiO2 that is caused by the increased electron lifetime.