Donor-acceptor-type polymers based on dithieno[2,3-b;7,6-b]carbazole unit for photovoltaic applications.

Dithieno[2,3-b;7,6-b]carbazole (TCZT), a type of heteropentacene with nitrogen and sulfur atoms, was synthesized with a focus on the unique reactivity of carbazole via double intramolecular Friedel-Crafts acylation. A donor-acceptor-type polymer (PTCZTBT) was also synthesized, and its physicochemical properties are reported.