TiO2 Microspheres: Formation and Performance Improvement for Dye-Sensitized Solar Cells

TiO2 microspheres were synthesized by a facile hydrothermal method using TiCl4 and oncentrated hydrochloric acid (36.5%similar to 38% by weight) as raw materials. The structures and morphologies of the obtained samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). In order to improve the performance of DSSC, double-layerd photoanode was fabricated by using TiO2 microshperes as the reflecting layer. The result shows that the TiO2 photoanode made of TiO2 microshperes and TiO2 nanoparticles exhibits an open-circuit photovoltage (V-oc) of 0.74, a short-circuit photovoltage (J(sc)) of 17.64 mA.cm(-2), a fill factor (FF) of 0.63, which lead to an overall energy-conversion efficiency (eta) of 8.33% under the illumination of one sun (AM 1.5, 100 mW.cm(2)). Compared with those electrodes made of TiO2 microspheres, enhanced light harvesting efficiency based DSSC was observed. Dye loading, light scattering property of the photoanodes and electrical impedance spectra of DSSCs were further analysised.