Nanostructured Porous Film of Doped TiO2-Anatase Semiconductor for Dye Sensitized Solar Cells (DSSCs)

Some results dealing with the synthesis, characterization and functional properties, as DSSC photo-anode active material, of solid solutions of nanostructured oxide materials hierarchically organized will be presented. The host lattice is TiO2-anatase and solute is a metal cation aliovalent with respect to Ti (IV). The scope of this work is to modify usefully the band structure of anatase with respect to the electronic levels of the light harvesting dye and to improve its electronic conductivity due to the creation of donor or acceptor levels. The final objective is to increase the DSSC conversion yield through searching for the better electronic coupling TiO2-anatase/dye since this is one of the necks that influence the whole efficiency of a DSSC. Another cause of the lack of efficiency is the electron-hole recombination in the TiO2-anatase film and we obtained satisfactory results [1] by TiO2-anatase/MWCNT nanocomposites that behave as Schottky junctions being multi walled carbon nanotubes (MWCNT) electronic conductors. In this way, the probability of recombination is reduced since electron paths shorter than the electron diffusion length in the semiconductor are created. The results obtained by doping TiO2-anatase with Nb5+ and Sc3+ will be the object of our contribution with the following items: • Synthesis of doped nanostructured TiO2-anatase with related structural and morphological characterizations; • Characterization of the electronic properties with respect pure TiO2-anatase through the flat band potential and carrier concentration measurements by the Mott-Schottky technique and band gap via diffuse reflectance; • Characterization and testing of our DSSCs realized with photo-anodes containing the above doped TiO2-anatase nanostructured materials.