1. Department of Physics, City University of Hong Kong, Kowloon 999077, Hong Kong, China
2. International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
3. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices and School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, China
4. Department of Chemistry, University of Hamburg, Harbor Bldg. 610, Luruper Chaussee 149, 22761 Hamburg, Germany
5. The Hamburg Centre for Ultrafast Imaging, University of Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
6. School of Chemistry, Chemical Engineering and Life Science, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China