1. State Key Laboratory for Mesoscopic Physics and Frontiers, Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
2. Nanjing Electronic Devices Institute, East Zhongshan Road, Nanjing 210016, China
3. Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China