1. Beijing National
Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids,
Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
2. School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
3. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
4. Department
of Physics and Astronomy, and Collaborative Innovation Center of IFSA
(CICIFSA), Shanghai Jiaotong University, Shanghai 200240, P. R. China