Development of porphyrin-polydiacetylene compounds as photosensitizers in organic solar cells

Abstract

Porphyrinic compounds have been known to be potential candidate for organic solar cells, owing to their large molar absorption coefficients, tunable photophysical properties, and amenability to molecular modification. In this research, synthesis of a series of diacetylene meso-substituted porphyrins with and without carboxyl anchoring group was pursued. The incorporation of polydiacetylene in the porphyrinic structure is expected to provide enhanced absorption at 550–600 nm where the porphyrin has limited absorptivity, improved film uniformity and enhanced solubility. The porphyrin bearing diacetylene units at all 4 meso positions will be used in bulk heterojunction solar cell. In case of the porphyrin having 3 diacetylene chains, the remaining meso position will be replaced by a carboxyl anchoring group and the compound will be used in dye-sensitized solar cells. Furthermore, benchmark compounds bearing long saturated alkyl meso-substituents were also synthesized and investigated in comparison with the diacetylene containing derivatives.