Bis(benzoselenadiazol)ethane: A π‐Extended Acceptor‐Dimeric Unit for Ambipolar Polymer Transistors with Hole and Electron Mobilities Exceeding 10 cm² V⁻¹ s⁻¹

The lack of ambipolar polymers with balanced hole ( μ h ) and electron mobilities ( μ e ) >10 cm 2 V −1 s −1 is the main bottleneck for developing organic integrated circuits. Herein, we show the design and synthesis of a π‐extended selenium‐containing acceptor‐dimeric unit, namely benzo[ c ][1,2,5]selenadiazol‐4‐yl)ethane (BBSeE), to address this dilemma. In comparison to its sulfur‐counterpart, BBSeE demonstrates enlarged co‐planarity, selective noncovalent interactions, polarized Se−N bond, and higher electron affinity. The successful stannylation of BBSeE offers a great opportunity to access acceptor‐acceptor copolymer pN‐BBSeE, which shows a narrower band gap, lower‐lying lowest unoccupied molecular orbital level (−4.05 eV), and a higher degree of backbone planarity. Consequently, the pN‐BBSeE‐based organic transistors display an ideally balanced ambipolar transporting property with μ h and μ e of 10.65 and 10.72 cm 2 V −1 s −1 , respectively. To the best of our knowledge, the simultaneous μ h / μ e values >10.0 cm 2 V −1 s −1 are the best performances ever reported for ambipolar polymers. In addition, pN‐BBSeE shows an excellent shelf‐storage stability, retaining over 85 % of the initial mobility values after two months storage. Our study demonstrates the π‐extended acceptor‐dimeric BBSeE is a promising acceptor building block for constructing high‐performance ambipolar polymers applied in next‐generation organic integrated circuit.