Ladder-Type Heteroacene Polymers Bearing Carbazole and Thiophene Ring Units and Their Use in Field-Effect Transistors and Photovoltaic Cells

Abstract

A ladder-type π-excessive conjugated monomer(dicyclopentathienocarbazole) integrating the structural components of carbazole and thiophene into a single molecular entity is synthesized and polymerized by oxidative coupling to yield poly(dicyplopentathienocarbazole) (PDCPTCz). Moreover, through the careful selection of 2,1,3-benzothiadiazole unit as a π-deficient building block, the dicyclopentathienocarbazole-based copolymer (poly(dicyclopentathienocarbazole-alt-2,1,3-benzothiadiazole) (PDCPTCz-BT)) is prepared by Suzuki polycondensation. The optical, electrochemical, and field-effect charge transport properties of the resulting polymers (PDCPTCz and PDCPTCz-BT) are not only characterized in detail but also their bulk-heterojunction (BHJ) solar cell in combination with PC71BM are evaluated.