1. Key Laboratory of Polar Materials and Devices (MOE) and Department of Electronics, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
2. State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
3. State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
4. Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China