Modification of electrodes in nanocrystalline dye-sensitized TiO2 solar cells

Influence of an electrodeposited overlayer and a spin-coated underlayer of TiO2 electrode on the cell performance was studied. The effect of annealing TiO2 electrode in O-2 atmosphere was also investigated. XRD analysis made on TiO2 by the sol-gel method showed a pure anatase phase. Electrodeposited TiO2 film showed two times larger surface area and O-2 annealed TiO2 showe d three times larger surface area than untreated TiO2. Electrodeposition of TiO2 resulted in sub-particles on base TiO2 and increased the surface area and the short-circuit current (J(sc)). For an underlayer, TiCl4, treatment caused no noticeable changes in current-voltage characteristics. Annealing in O-2 atmosphere did not cause any apparent changes in bonding characteri stics judging from XPS measurement. A conversion efficiency up to 5.8% was obtained. (C) 2001 Elsevier Science B.V. All rights reserved.