Highly Ordered Nanotube Arrays as Photo-Anodes for Dye-Sensitized Solar Cells by Electrochemical Method

Symmetrically packed TiO2 nanotubes (TNTs) were fabricated in fluorine free perchloric acid medium by electrochemical anodization method. During anodization interconnected pores developed by forming amorphous/ hydroxides of titanium film. On increasing anodization, thickness of film increased and pores tend to become aligned providing surface layer of nanotubes on the electrode material. The 1-D charge carrier transport property of the tubular geometry have attracted scientists attention in using TNTs for TiO2 photovoltaic and photo catalysis applications. By controlling the anodization process, the length, diameter and wall thickness of TNTs can be tailored. The iron and chromium doped highly ordered 1-D TNTs obtained during anodization are superior photoanodes for dye-sensitized solar cells because of its reduced inter tube connections, vertical electron transport, suppressed electron recombination and enhanced current density, efficiency in power conversion and light scattering. The morphological characteristics and microstructure of TNTs were investigated by SEM and X-ray diffraction analysis. Diffusion electron spectroscopy has been used to analyze the amount absorption of the dye on the surface of the various TNT, which acknowledges the direct co relation between the dye absorption and morphology of the sample.