1. State Key Laboratory of Silicon Materials, School of
Materials Science and Engineering, Cyrus Tang Center for Sensor Materials
and Application, Zhejiang University, Hangzhou 310027, China
2. Key Laboratory of Advanced Technique & Preparation for Renewable Energy Materials, Ministry of Education, Yunnan Normal University, Kunming 650500, China
3. Science and Technology on Surface Physics and Chemistry Laboratory, P.O. Box 718-35, Mianyang 621907, China
4. Institute
for Quantum Science and Engineering and Department of Physics, South University of Science and Technology of China, Shenzhen 518055, China
5. Center of Electron Microscope, School of
Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
6. State Key Laboratory
for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China