Spectral broadening in nanocrytalline TiO2 solar cells based on poly(p-phenylene ethynylene) and polythiophene sensitizers

Spectral broadening in the fabrication of nanocrystalline titanium dioxide (TiO2) dye-sensitized solar cells (DSSCs), based on poly(p-phenylene ethynylene) (PPE) and poly-thiophene (PT), is discussed. The films of nanocrystalline TiO2 were coated on fluorine-doped tin oxide (FTO) glass substrate. It was observed that carboxylated PPE (PPE-CO2) and carboxylated PT (PT-CO2) form uniform coatings on TiO2 films. It was also observed that the combined PPE-CO2/PToCO 2 photocurrent is a contribution from both the individual polymers. Conjugated polyelectrolytes (CPEs), with their high absorption coefficients and tunable band gaps spanning a broad portion of the visible and near-infrared spectrum, serve as alternative light-harvesting and charge transfer material in these cells.