1. Key Laboratory of Automobile Materials of MOE, College of Materials Science and Engineering, Jilin University, Changchun 130012, China
2. Laboratory of Microfabrication, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
3. Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
4. State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun 130012, China
5. Department of Physics and Astronomy and Department of Chemistry, University of Missouri, Columbia, Missouri 65211-7010, United States