1. Center of Electron Microscopy and State Key Laboratory of Silicon Materials School of Materials Science and Engineering Zhejiang University Hangzhou 310027 China
2. Materials Chemistry and Catalysis Debye Institute for Nanomaterials Science Utrecht University 3584 CG Utrecht The Netherlands
3. Hitachi High-Tech (Shanghai) Co., Ltd. Shanghai 201203 China
4. Interdisciplinary Research Center, Zhangjiang Laboratory Shanghai Advanced Research Institute, Chinese Academy of Sciences Shanghai 201210 China