1. Department
of Materials Science and Engineering, College of Engineering, Key
Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing 100871, China
2. Department
of Chemistry, Capital Normal University, Beijing 100048, China
3. Institute
of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
4. Heeger
Beijing Research and Development Center, School of Chemistry and Environment, Beihang University, Beijing 100191, China
5. State
Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China
6. School
of
Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States