Influence of the size-controlled TiO2 nanotubes fabricated by low-temperature chemical synthesis on the dye-sensitized solar cell properties

Abstract

Titanium dioxide nanotubes (TiO2 NTs) with various sizes have been prepared by low-temperature chemical synthesis using commercial anatase TiO2 particles with different crystallite size in NaOH solution and used as a photoelectrode in a dye-sensitized solar cell (DSSC). The relationship between the physicochemical properties of electrode materials and photovoltaic performance was investigated. The electrodes made from modified TiO2 NTs showed a strong dependency on their specific surface area and resultant amount of dye adsorption; the surface area decreased with increase in the diameter of the NT from 9.8 to 23.6 nm. The conversion efficiency of the cell made from TiO2 NT, 12.9 nm in diameter, was enhanced by 12% compared to that of the smallest NT. These results suggested that the photovoltaic performance improved by the suppression of photogenerated charge recombination in spite of a 25.3% reduction in the specific surface area. In addition, larger TiO2 NTs could be utilized as a scattering layer on the top of the TiO2 nanoparticulate working electrode. It was observed that this controlled TiO2 photoelectrode architecture exhibited enhanced conversion efficiency without TiCl4 treatment. ©Springer Science+Business Media, LLC 2010.