1. School of Integrated Circuits and State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China
2. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
3. School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
4. College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 101408, China
5. School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
6. Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China