Resistivity reduction in flexible dye sensitized solar cells by UV irradiation and carbon nanotubes

High efficient flexible dye sensitized solar cells use ITO covered foils as a conductive transparent layer, expensive dyes on Ru-base as the light absorbing material, and Pt or Pd as the catalyst, located on the counter electrode. Cheaper devices replace the Ru complex by natural dyes and apply carbon as the catalyst. The resulting lower efficiency can be partly compensated by an UV-treatment of the nano particulate TiO₂ film and by a reduction of the internal cell resistivity. Carbon nanotubes are capable to replace the pure carbon catalyst layer in the solar cell setup.