Mesoporous TiO2 spheres as a photoanodic material in dye-sensitized solar cells

Mesoporous TiO2 films with spherical architectures and promising performance in dye-sensitized solar cells (DSSCs) were prepared. The morphology of the films was investigated by scanning electron microscopy. Transmission electron microscopy analysis of the spheres disclosed the elongated shape of sub-20nm primary particles, while BET analysis revealed their high surface area of 135 m(2)/g. Anatase presence was observed in the films based on X-ray diffractometry, selected-area electron diffraction analysis and Raman spectroscopy analyses. Increased light scattering of the spheres in visible region was observed by UV-VIS-NIR spectroscopy. Photovoltaic performance of the operating N719-sensitized cells was tested using electrochemical impedance spectroscopy and current density-voltage (J-V) curves under simulated AMI. 5 spectrum. The 0.25 cm(2) cells exhibited photo-to-electric power efficiency of 4.9%, which is among noteworthy values for DSSCs with similar photoanodic structures.