Regioregular Polythiophene-Porphyrin Supramolecular Copolymers for Optoelectronic Applications

Abstract

Conjugated poly(3-hexylthiophene) copolymer derivatives containing 10% appended porphyrin moieties are prepared using a supramolecular approach toward applications in organic electronics. The self-assembled polythiophene-porphyrin copolymers are synthesized by coordination of the porphyrinato central zinc ions to the imidazole-functionalized polythiophene side chains. Evidence for the self-assembly process is provided by H-1 NMR spectroscopy, single crystal X-ray diffraction, and optical absorption studies on model compounds. The polythiophene-porphyrin copolymers show an extended absorption window in the region of 420-650 nm due to the contribution of the porphyrin. Photoluminescence studies indicate concentration-dependent energy transfer from P3HT to the porphyrin. Preliminary photovoltaic studies are performed by combining the polythiophene-porphyrin copolymers with PC61BM in the photoactive layer of bulk heterojunction organic solar cells.