Ultra‐Low Threshold Voltage in N‐Type Organic Electrochemical Transistors Enabled by Organic Mixed Ionic‐Electronic Conductors with Dual Electron‐Withdrawing Substitutions
Riqing Ding, Xiage Zhang, Ran Yan, Meishan Peng, Shengyao Su, Sang Young Jeong, Han Young Woo, Xugang Guo, Kui Feng, Zihao Guo
Abstract
Abstract Achieving low threshold voltage ( V th ) in organic electrochemical transistors (OECTs) is essential for minimizing power consumption and enhancing sensitivity in bioelectronic devices. However, obtaining OECT materials with ultra‐low V th , close to 0 V for n‐type conjugated polymers remains challenging. Here, a conjugated polymer FBDOPV‐CNTVT is introduced, which features a rigid backbone structure and high electron deficiency, leading to an exceptionally low lowest unoccupied molecular orbital (LUMO) energy level of −4.67 eV, achieved through dual electron‐withdrawing substitutions. With its ultra‐low LUMO energy level, FBDOPV‐CNTVT exhibits high susceptibility to electrochemical doping, even demonstrating efficient doping near 0 V. Consequently, the OECT device employing FBDOPV‐CNTVT as the active material shows an ultra‐low V th of 7.5 mV, setting a new record for the V th of n‐type OECT devices. Furthermore, FBDOPV‐CNTVT exhibits a µC * value of 6.13 F cm −1 V −1 s −1 and retains ≈85% of its current after 2000 s cycling. This study highlights the potential of conjugated polymers with dual electron‐withdrawing substitutions to achieve ultra‐low LUMO energy levels, effectively reducing the V th of n‐type OECT devices and promising advancements in bioelectronics.