Investigation of Deformed TiO2 Aggregates Doped TiO2 Nanoparticles Photoanode Applied for Dye-Sensitized Solar Cells

Deformed TiO2 aggregates (DTA) were synthesized for improving the energy conversion efficiency and used in the photoanode of dye-sensitized solar cells (DSSCs). The mesoporous DTA was composed of primary nanoparticles with a particle size of approximately 13.4 nm and had an overall dimension of about 300-600 nm measured by using transmission electron microscope and field-emission scanning electron microscope. TiO2-P25 film (P25), DTA film and DTA-doped TiO2-P25 film (DMP) were fabricated by using doctor-blade technique. The topographies of the photoanode film were also revealed by using scanning probe microscope to provide evidence for the influence of the roughness on the electrochemical interface. The UV-Vis spectra showed that the absorbance of the DMP film was superior to the P25 and DTA film in the region of whole visible wavelengths. The DMP film represented a low interface impedance and a longer electron lifetime, which were indicated from electrochemical impedance spectroscopy analysis. DSSC based on DMP film showed a photovoltaic conversion efficiency of 5.34% with a working area of 1.0 cm(2) under a standard solar light source of 100 mW/cm(2).