Switching p-type to high-performance n-type organic electrochemical transistors via doped state engineering

• Published in: Nature communications 2022-10, Vol.13 (1), p.5970-5970, Article 5970
• Main Authors: Li, Peiyun, Shi, Junwei, Lei, Yuqiu, Huang, Zhen, Lei, Ting
• Format: Article
• Language: English
• Subjects: 147/3; 639/301/1005/1007; 639/638/298/917; Conformation; Electrochemistry; Energy levels; Engineering; Humanities and Social Sciences; Logic circuits; Molecular orbitals; multidisciplinary; Polymers; Science; Science (multidisciplinary); Semiconductor devices; Transistors
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-33553-w

High-performance n-type organic electrochemical transistors (OECTs) are essential for logic circuits and sensors. However, the performances of n-type OECTs lag far behind that of p-type ones. Conventional wisdom posits that the LUMO energy level dictates the n-type performance. Herein, we show that engineering the doped state is more critical for n-type OECT polymers. By balancing more charges to the donor moiety, we could effectively switch a p-type polymer to high-performance n-type material. Based on this concept, the polymer, P(gTDPP2FT), exhibits a record high n-type OECT performance with μC * of 54.8 F cm −1 V −1 s −1 , mobility of 0.35 cm 2 V −1 s −1 , and response speed of τ on / τ off  = 1.75/0.15 ms. Calculations and comparison studies show that the conversion is primarily due to the more uniform charges, stabilized negative polaron, enhanced conformation, and backbone planarity at negatively charged states. Our work highlights the critical role of understanding and engineering polymers’ doped states. Conventional strategies to obtain n-type organic electrochemical transistors are based on lowering the lowest unoccupied molecular orbital. Here Lei et al., engineer the polymer doped states to fabricate high-performance n-type organic electrochemical transistors.