π-Conjugated Polymers for High-Performance Organic Electrochemical Transistors: Molecular Design Strategies, Applications and Perspectives

The last decade has witnessed significant progress in organic electrochemical transistors (OECTs) due to their enormous potential applications in various bioelectronic devices, such as artificial synapses, biological interfaces, and biosensors. The remarkable advance achieved in this filed is highly powered by the development of novel organic mixed ionic/electronic conductors (OMIECs). Among these, π-conjugated polymers (CPs), which are widely used in various optoelectronics, are emerging as key channel materials for OECTs. In this review, after briefly introducing of OECT, we then mainly focus on the latest progress in CPs for high-performance OECTs. The correlations of their structure, basic physicochemical properties, and device performance are further elucidated via evaluating their electronic characters, optoelectronic properties, and OECT performance. Then, the applications of CP-based OECTs are briefly presented. Finally, we discuss several remaining issues or challenges in this field and give our insight into advancing CPs for enhanced OECT performance.