Quinoxaline‐Based Single‐Component Ambipolar Polymer for Organic Electrochemical Transistors

Ambipolar organic mixed ion‐electron conductors (OMIECs) are essential for simplifying the fabrication of organic electrochemical transistor (OECT)‐based complementary logic circuits and bioelectronics. However, the limited availability of ambipolar OMIEC materials restricts their further advancement. By incorporating a thiadiazol ring fusion onto the quinoxaline building block and introducing difluorobenzothiadiazole as a secondary acceptor, we successfully synthesized a novel ambipolar OMIEC named TdQ‐DT2FBT. Due to the strong electron‐withdrawing capability of the [1,2,5]thiadiazolo[3,4‐g]quinoxaline (TdQ) unit, TdQ‐DT2FBT has achieved a narrow bandgap of 1.16 eV. TdQ‐DT2FBT demonstrates a high product of mobility and capacitance ( µC* ) of 301.03 F cm −1 V −1 s −1 for the p‐type mode and a respectable µC* of 11.27 F cm −1 V −1 s −1 for the n‐type mode. Vertical OECTs were fabricated, achieving high and relatively balanced ambipolar properties with transconductance values of 211.50 mS for the p‐type mode and 79.77 mS for the n‐type mode. Furthermore, a vertical complementary inverter was developed, achieving a gain of 78 V V −1 at V dd = 1.0 V, and a voltage amplification gain of approximately 15 for electrooculogram recording. This work presents a novel quinoxaline‐based single‐component organic mixed ionic‐electronic conductor (OMIEC), paving the way for the fabrication of high‐performance ambipolar OECTs and related complementary circuits.