1. Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, 199 Ren-Ai Road, Suzhou Industrial Park, Suzhou, Jiangsu 215123, P.R. China
2. Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195-2120, United States
3. HEEGER Beijing Research & Development Center, School of Chemistry, Beihang University, Beijing 100191, China