1. School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China
2. State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China
3. Shijia Photonics Technology, Hebi 458030, P. R. China
4. Key Laboratory for Light-Weight Materials, Nanjing Tech University, Nanjing 210009, P. R. China