Role of the Bulky Aryloxy Group at the Non-Peripheral Position of Phthalocyanines for Dye Sensitized Solar Cells

• To date β-aryloxy-substituted designs have led to the best results in phthalocyanine-sensitized solar cells (Pc-SCs) because of their low aggregation properties. By incorporating the bulky semiflexible 2,6-diphenylphenoxy group at three α-positions of the Pc, different regioisomers were sepd. by column chromatog. and their photovoltaic performance was thoroughly studied. Efficiencies in the range of 1.9-4.1 % were found, thus demonstrating the importance of the steric interaction between the substituents and the semiconductor surface, also in the case of bulky semiflexible substituents. It .