Natural Flavonoids as Potential Photosensitizers for Dye-Sensitized Solar Cells

Natural flavonoids quercetin, morin, fisetin and luteolin were studied as potential photosensitizers for dye-sensitized solar cells (DSSC). Spectroscopic methods were used to investigate the formation of dye/TiO₂ nanoparticles assemblies and the development of their absorption spectra. The results show that the flavonoids adsorb well on TiO₂ nanoparticles and this process causes the shift of absorption spectra from the near UV into the visible range of solar light. The mode of binding of the dye molecules on TiO₂ surface is analyzed by comparison of spectral absorption properties and with the use of structural differences introduced by fisetin and luteolin for discrimination between several possibilities.