Titanium oxide hollow structure layer for dye sensitized solar cell by liquid phase deposition

Abstract

In this study, polystyrene (PS) microspheres templates having different coating densities were prepared by drop casting PS microspheres with the diameter of 800\xa0nm on indium tin oxide (ITO) glass substrate. TiO2 film was deposited on the PS microsphere template via liquid phase deposition (LPD) using a solution of ammonium hexafluoro-titanate [(NH4)2TiF6] and boric acid (H3BO3). A LPD-TiO2 hollow layer was prepared by removing PS microspheres via high-temperature sintering; this hollow layer acts as a barrier between the ITO and electrolyte interface in the working electrode structure of a dye-sensitized solar cell (DSSC). Because hollow layer has a large specific surface area, it increases dye adsorption and acts as a barrier layer to inhibit direct contact between ITO and electrolyte interface. Thus, the charge recombination rate between ITO and electrolyte interface is reduced and the electron transmission efficiency between the ITO and the working electrode is improved. Hollow layer (0.1\xa0wt% PS, 50\xa0nm) in the DSSC exhibited the optimum short-circuit current density (Jsc) of 12.75\xa0mA/cm2, open-circuit voltage (Voc) of 0.71\xa0V, fill factor of 62.19%, and photoelectric conversion efficiency (η) of 5.67%.