Integrated Top‐Gate Organic Electrochemical Transistors: A Scalable Approach for Fast and Efficient Operation

Abstract Organic electrochemical transistors (OECTs) are gaining attention for their ease of fabrication, flexibility, and biocompatibility, with applications in biosignal sensing, neuromorphic computing, wearable health monitors, environmental monitoring, and bioelectronic interfaces. The interactions between ionic and electronic subcircuits in OECTs raise fundamental questions about the relationship between device design and performance. A major challenge is to meet specific integration, processing, and device performance requirements. While miniaturization of OECTs can improve transconductance and maximum operating frequency, it often compromises cost effectiveness and integratability. This work investigates an OECT architecture that incorporates both a crosslinkable printed aqueous electrolyte and a printed poly(3,4‐ethylenedioxythiophene):ploy(4‐styrenesulfonate) (PEDOT:PSS) top‐gate to achieve efficient gating, higher operating frequencies, and easy integration with low‐cost printing techniques. Improved performance is demonstrated in this top‐gate OECTs over conventional side‐gate structures, achieving sub‐millisecond device operation with channel lengths of 100 µm. This configuration shows practical potential for circuit integration, as demonstrated with a complementary inverter using an ambipolar material.