1. Department of Materials Science and Engineering, and Organic and Carbon Electronics Laboratories (ORaCEL), North Carolina State University Raleigh, Raleigh, North Carolina27695, United States
2. Department of Physics, and Organic and Carbon Electronics Laboratories (ORaCEL)North Carolina State University Raleigh, Raleigh, North Carolina27695, United States
3. Department of Physics and Institute of Advanced Materials, Hong Kong Baptist University, Kowloon Tong, Hong Kong, People’s Republic of China
4. School of Chemistry and Biochemistry School of Materials Science and Engineering Center for Organic Photonics and Electronics, Georgia Tech Polymer Network, Georgia Institute of TechnologyAtlanta, Georgia30332, United States