Free-base tetra-arylphthalocyanines for dye-sensitised nanostructured solar cell applications

Adsorption of phthalocyanines lacking conventional attaching substituents onto nanostructured TiO2 electrodes has been studied, and some of the important factors for sensitisation have been identified. Tetra-dimethoxyphenyl phthalocyanine (2) and tetra-phenyl phthalocyanine (3), derived from 4-(2,5-dimethoxyphenyl)phthalonitrile and 4-phenylphthalonitrile, respectively, are shown to successfully sensitise nanostructured TiO2 electrodes, with IPCEmax of 9 and 5% at lambda = 650 nm. The dye-oxide systems have been characterised by UV-vis spectroscopy, cyclic voltammetry and photoelectrochemical methods, and the dye-surface interactions are discussed. Copyright (C) 2001 John Wiley & Sons, Ltd.