A novel covalently linked Zn phthalocyanine-Zn porphyrin dyad for dye-sensitized solar cells
A novel Zn phthalocyanine-Zn porphyrin (ZnPc-ZnPor) dyad (1), in which a zinc porphyrin moiety is linked covalently with an ABAB-type zinc phthalocyanine moiety, has been designed and synthesized. The ZnPc-ZnPor dyad 1 can absorb over a wide spectral range of visible light. The fluorescence spectrum of dyad 1 revealed an intramolecular efficient energy transfer from Zn porphyrin to Zn phthalocyanine. When dyad 1 was used as a light-harvesting sensitizer for dye-sensitized solar cells, the cell sensitized by dyad 1 provided a power conversion efficiency of 2.7% under simulated air mass 1.5 global sunlight. The incident photon-to-current efficiency spectrum of the dyad 1 cell suggested the contribution of both components in dyad 1 for the current generation.