1. Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing 100081, China
2. Guangxi Key Lab of Processing for Nonferrous Metals and Featured Materials and Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Ministry of Education, and Nano and Energy Research Center, School of Physics, Guangxi University, Nanning 530004, China
3. Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China