1. Department
of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong SAR, China
2. City University of Hong
Kong Shenzhen Research Institute, Shenzhen 518057, China
3. Department
of Applied Physics, The Hong Kong Polytechnic University, Hong Hum, Hong Kong
SAR, China
4. Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics & Energy, Shenzhen University, Shenzhen 518060, China
5. Univ Lyon, Université
Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
6. State
Key Laboratory of Silicon Materials, School of Materials Science and
Engineering, Zhejiang University, Hangzhou 310027, China