1. Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
2. Key Lab of Supramolecular Structure
and Materials, Jilin University, Changchun
130023, China
3. Institute of
Mechanics, Chinese Academy of Sciences,
Beijing 100190, China
4. Department
of Physics, University of Maryland, Maryland
20742, United States
5. Stephenson
Institute for Renewable
Energy, The University of Liverpool, Liverpool,
L69 3BX, Umited Kingdom
6. Materials
Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee
37831, United States