1. Department
of Physics, Institute of Advanced Materials and Institute of Research
and Continuing Education (Shenzhen), Hong Kong Baptist University, Kowloon
Tong, Hong Kong, China
2. Laboratory
of Advanced Optoelectronic Materials, College of Chemistry, Chemical
Engineering and Materials Science, Soochow University, Suzhou 215123, China
3. CAS
Research/Education Center for Excellence in Molecular Sciences, CAS
Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China