Ambipolar Semiconducting Polymers with π-Spacer Linked Bis-Benzothiadiazole Blocks as Strong Accepting Units

Recognizing the importance of molecular coplanarity and with the aim of developing new, ideal strong acceptor-building units in semiconducting polymers for high-performance organic electronics, herein we present a simplified single-step synthesis of novel vinylene- and acetylene-linked bis-benzothiadiazole ( VBBT and ABBT ) monomers with enlarged planarity relative to a conventionally used acceptor, benzothiadiazole (BT). Along these lines, four polymers ( PDPP-VBBT, PDPP-ABBT, PIID-VBBT, and PIID-ABBT ) incorporating either VBBT or ABBT moieties are synthesized by copolymerizing with centro-symmetric ketopyrrole cores, such as diketopyrrolopyrrole (DPP) and isoindigo (IID), and their electronic, physical, and transistor properties are studied. These polymers show relatively balanced ambipolar transport, and PDPP-VBBT yields hole and electron mobilities as high as 0.32 and 0.13 cm 2 V –1…