1. Advanced Materials
Institute, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China
2. School
of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
3. Department of Physics
and Astronomy, California State University Northridge, 18111 Nordhoff
Street, Northridge, California 91330-8268, United States
4. Materials Science Institute, PCFM Lab and GDHPPC Lab, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
5. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States