Cross-Conjugated Donor-Acceptor Polymers for High-Performance Organic Electrochemical Transistors

The development of high-performance polymer mixed ionic-electronic conductors (PMIECs) is critical for advancing organic electrochemical transistors (OECTs). While the field has been dominated by linearly conjugated polymers, cross-conjugated systems represent a vast and largely unexplored materials platform. Their distinctive optical, electronic, and tailorable redox characteristics endow them with considerable, yet underutilized, potential for the development of a range of OECT applications. In this work, we designed and synthesized two donor-acceptor (D-A) polymers, P-(TIDPg-TVT) and P-(TIDPg-CNTVT), based on a planar, hydrogen-bond-locked cross-conjugated acceptor (TIDP). P-(TIDPg-TVT) exhibited n-type-dominant ambipolar transport coupled with high operational stability, achieving an n-type μC* of 3.25 F cm^-1 V^-1 s^-1. The cyanofunctionalized polymer P-(TIDPg-CNTVT) displayed pronounced n-type characteristics, achieving a high μC* of 4.93 F cm^-1 V^-1 s^-1 along with efficient doping. Leveraging these polymers as the active layer, complementary OECT inverters were fabricated and demonstrated high voltage gains. This work successfully validates cross-conjugation as a versatile design paradigm for high-performance PMIECs, thereby providing a molecular engineering strategy to realize balanced ionic and electronic transport, which is critical for the development of high-performance organic bioelectronic devices.