A combined TiO2 structure with nanotubes and nanoparticles for improving photoconversion efficiency in dye-sensitized solar cells

A novel combined structure with a mixture of TiO2 nanotubes and nanoparticles was fabricated by anodization of Ti, followed by a controlled annealing post-treatment. The TiO2 nanoparticles with the average diameter of 40 nm were uniformly dispersed on the surface of TiO2 nanotubes with the diameter of 110-130 nm and the length of 15 mu m. The photoelectric behavior of the as-prepared photoanode in dye-sensitized solar cells was analyzed by the measurements of I-V and EIS. It was found that the energy conversion efficiency of the solar cell with composite photoanode was 5.75%, enhanced up to 25.8% compared to that of the photoanode of pure TiO2 nanotube structure in the same condition. (C) 2012 Elsevier Ltd. All rights reserved.