Boosting stability and charge transfer of conducting polymer poly(benzodifurandione) (PBFDO) through complementary topology

Poly(benzodifurandione) (PBFDO) is a benchmark n-type conjugated polymer known for its record-high electrical conductivity. Nevertheless, its thermal robustness and charge/ion transport characteristics remain insufficient. To address this issue, we report a hierarchical complementary topology strategy via doping PBFDO with choline chloride (ChCl). At the molecular scale, the cations Ch + selectively intercalate along the out-of-plane direction while simultaneously densifying the in-plane π-π stacking, accompanied by partial removal of H + . At the submicrometer scale, this induces distinct phase separation into high- and low-density stacking domains. As a result, the product PBFDO-ChCl exhibited a synergistic performance boost, with a 2.8-fold enhancement in high-temperature resilience, a 1.6-fold increase in sheet conductance, and a 15.9-fold reduction in ion diffusion resistance. Then, organic electrochemical transistors (OECTs) using PBFDO-ChCl as channel material further confirm these performance enhancements. As a whole, this work closes the performance gap between n-type PBFDO and state-of-the-art p-type conjugated polymers, potentially advancing its applications from energy storage to bioelectronics and neuromorphic computing.