1. State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China
2. Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 eighth Street, Troy, New York 12180, United States
3. State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China