1. Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
2. Beijing Institute of Technology Chongqing Innovation Center, Chongqing 401120, PR China
3. Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing 314019, PR China
4. Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
5. Key Laboratory of Cluster Science Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, P. R. China
6. School of Physics, Beijing Institute of Technology, Beijing 100081, P. R. China