Enhancing the Backbone Coplanarity of n-Type Copolymers for Higher Electron Mobility and Stability in Organic Electrochemical Transistors

• DOI: 10.1021/acs.chemmater.2c01552
• Publication Date: 2022-09-27T17:05:40Z
• Authors: Iuliana P. Maria; Sophie Griggs; Reem B. Rashid; Bryan D. Paulsen; Jokubas Surgailis; Karl Thorley; Vianna N. Le; George T. Harrison; Craig Combe; Rawad Hallani; Alexander Giovann...; Alexandra F. Pate...; Sahika Inal; Jonathan Rivnay; Iain McCulloch
• Keywords: Coplanarity; Side chain

Electron-transporting (n-type) conjugated polymers have recently been applied in numerous electrochemical applications, where both ion and electron transport are required. Despite continuous efforts to improve their performance stability, n-type with mixed conduction still lag behind hole-transporting (p-type) counterparts, limiting the functions of devices. In this work, we investigate effect enhanced backbone coplanarity on activity ionic-electronic properties during operation aqueous media. Through substitution widely employed electron-deficient naphthalene diimide (NDI) unit for core-extended naphthodithiophene (NDTI) units, resulting polymer shows a more planar closer packing, leading an increase mobility organic transistors (OECTs) by than two orders magnitude. The NDTI-based deep-lying lowest unoccupied molecular orbital level, enabling OECT 0 V vs Ag/AgCl, fewer parasitic reactions oxygen occur. Enhancing also leads lower affinity toward water uptake cycling, improved stability charging ON-OFF switching relative NDI derivative. Furthermore, demonstrates near-perfect shelf-life over month-long test, exhibiting negligible decrease maximum on-current transconductance. Our results highlight importance design developing stable, high-performing materials