1. College of Optical and Electronic Technology, China Jiliang University, Hangzhou 310018, P. R. China
2. State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China
3. Ioffe Institute, 26 Politekhnicheskaya, St Petersburg, 194021, Russian Federation
4. Wenzhou Key Laboratory of Novel Optoelectronic and Nano Materials, Institute of Wenzhou, Zhejiang University, Wenzhou 325006, P. R. China