Nanostructured Titania Photoanodes for Dye Solar Cells

Dye-sensitized solar cells (DSSCs) have attracted intensive attention for their low cost and environmentally friendly comparing to the cells based on silicon. Acting as photoanodes, the nanostructured TiO2 affects the overall performance of DSSCs, that provides direct pathways for photogenerated electrons and enhance electron transport rate, significantly improve the charge collection efficiency. In this work, nanostructured Titania (such as arrays and flowers) were fabricated on metallic Ti foils via a soft solution approach. It was found that by adding hexamethylenetetramine and nitric acid into reaction solution, titania nano arrays changed from nanorods to nanoflowers. Both films were employed to construct back-side illuminated dye-sensitized solar cells (DSSCs). The charge transport properties were investigated by the current to voltage curves and the electrochemical impedance spectroscopy (EIS). The photoelectric conversion efficiency of nanorod-derived DSSCs is about more than 150% higher than that of nanoflower-derived ones.