Layer-by-layer TiO2 films as efficient blocking layers in dye-sensitized solar cells

Charge recombination at the conductor substrate/electrolyte interface has been prevented by using efficient blocking layers of TiO2 compact films in dye-sensitized solar cell photoanodes. Compact blocking layers have been deposited before the mesoporous TiO2 film by the layer-by-layer technique using titania nanoparticles as cations and sodium sulfonated polystyrene, PSS, as a polyanion. The TiO2/PSS blocking layer in a DSC prevents the physical contact of FTO and the electrolyte and leads to a 28% increase in the cellʹs overall conversion efficiency, from 5.7% to 7.3%.