1. Beijing National
Laboratory for Molecular Sciences, State Key Laboratory for Structural
Chemistry of Unstable and Stable Species, College of Chemistry and
Molecular Engineering, Peking University, Beijing 100871, China
2. Department of Applied Physics, University of Tokyo, Hongo, Tokyo 113-8656, Japan
3. Beijing National Laboratory for Molecular
Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
4. Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
5. Key Laboratory for the
Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China
6. Department of Materials
Science and Engineering, College of Engineering, Peking University, Beijing 100871, China