High‐Performance n‐Type Polymeric Mixed Ionic‐Electronic Conductors: The Impacts of Halogen Functionalization

• Published in: Advanced materials (Weinheim) Vol. 36; no. 4; pp. e2305416 - n/a
• Main Authors: Yang, Wanli, Feng, Kui, Ma, Suxiang, Liu, Bin, Wang, Yimei, Ding, Riqing, Jeong, Sang Young, Woo, Han Young, Chan, Paddy Kwok Leung, Guo, Xugang
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.01.2024
• Subjects: Amplification; Charge transport; Conductors; Electron mobility; halogen functionalization; Inverters; Molecular orbitals; n‐type polymer semiconductors; organic electrochemical transistors; organic thermoelectrics; polymeric mixed ionic‐electronic conductors; Polymers; Power factor; Transport properties; Voltage gain; halogen functionalization; organic electrochemical transistors; polymeric mixed ionic-electronic conductors; n-type polymer semiconductors; organic thermoelectrics
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202305416

Developing high‐performance n‐type polymer mixed ionic‐electronic conductors (PMIECs) is a grand challenge, which largely determines their applications in vaious organic electronic devices, such as organic electrochemical transistors (OECTs) and organic thermoelectrics (OTEs). Herein, two halogen‐functionalized PMIECs f‐BTI2g‐TVTF and f‐BTI2g‐TVTCl built from fused bithiophene imide dimer (f‐BTI2) as the acceptor unit and halogenated thienylene–vinylene–thienylene (TVT) as the donor co‐unit are reported. Compared to the control polymer f‐BTI2g‐TVT, the fluorinated f‐BTI2g‐TVTF shows lower‐positioned lowest unoccupied molecular orbital (LUMO), improved charge transport property, and greater ion uptake capacity. Consequently, f‐BTI2g‐TVTF delivers a state‐of‐the‐art µC* of 90.2 F cm−1 V−1 s−1 with a remarkable electron mobility of 0.41 cm2 V−1 s−1 in OECTs and an excellent power factor of 64.2 µW m−1 K−2 in OTEs. An OECT‐based inverter amplifier is further demonstrated with voltage gain up to 148 V V−1, which is among the highest values for OECT inverters. Such results shed light on the impacts of halogen atoms on developing high‐performing n‐type PMIECs. Two halogen‐functionalized bithiophene imide dimer‐based n‐type polymer mixed ionic‐electronic conductors (PMIECS), f‐BTI2g‐TVTF and f‐BTI2g‐TVTCl, are synthesized, featuring deep‐positioned lowest unoccupied molecular orbital and favorable polymer chain packing motif. Polymer f‐BTI2g‐TVTF delivers a state‐of‐the‐art µC* of 90.2 F cm−1 V−1 s−1 in organic electrochemical transistors and an excellent power factor of 64.2 µW m−1 K−2 in organic thermoelectrics. Such results shed light on the impacts of halogen atoms on developing high‐performing n‐type PMIECS.