Backbone Engineering of Benzodifurandione‐Based n ‐Type OMIECs With Antiambipolar Behavior

ABSTRACT Organic mixed ionic‐electronic conductors (OMIECs) are key components for the next‐generation bioelectronics, albeit with n ‐type materials remaining significantly underrepresented compared to their p ‐type counterparts. Furthermore, reaching low operating voltages alongside high ambient and operational stability remains challenging when employing n ‐type OMIECs in organic electrochemical transistor (OECT)‐based applications. Herein, we report two novel n ‐type polymeric OMIECs, based on an azaisatin and benzodifurandione‐based backbone, incorporating either non‐fluorinated or fluorinated bithiophene donor units. The resulting polymers, obtained via Aldol polymerization, have high electron affinities of 4.5–4.7 eV. Both polymers function in n ‐type accumulation mode OECTs with indications of tunable antiambipolar behavior. The fluorinated polymer displays a low threshold voltage of 0.14 V, while the non‐fluorinated analogue offers excellent operational stability, with the OECT retaining 96% of its initial current after 1800 s of cycling.