1. School of Physics and Materials Science, Guangzhou University, Guangzhou 510006, China
2. Research Center for Advanced Information Materials (CAIM), Huangpu Research & Graduate School of Guangzhou University, Sino-Singapore Guangzhou Knowledge City, Guangzhou 510555, China
3. School of Mechanical and Mining Engineering, The University of Queensland Brisbane, Queensland 4072, Australia
4. School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
5. Key Lab of Si-based Information Materials & Devices and Integrated Circuits Design, Department of Education of Guangdong Province, Guangzhou 510006, China