Significant effects of the distance between the cyanine dye skeleton and the semiconductor surface on the photoelectrochemical properties of dye-sensitized porous semiconductor electrodes

The incident photon-to-current conversion efficiency (IPCE) of a porous TiO2 electrode sensitized by cyanine dyes increased with decreasing distance between the skeleton of the dye and the TiO2 surface. The photocurrent of oxide semiconductor electrodes sensitized by a cyanine dye increased with the positive shift of the conduction band potential of the oxide semiconductor in the following order: Nb2O5< TiO2< ZnO < SnO2. The SnO2 semiconductor cell showed the best light-to-electric conversion efficiency among the four semiconductors.