1. Department of Applied Physics The Hong Kong Polytechnic University Hung Hom Hong Kong China
2. College of Electronic Information and Mechatronic Engineering Zhaoqing University Zhaoqing Guangdong 526061 China
3. School of Physics and Material Science Nanchang University Nanchang Jiangxi 330031 China
4. School of Aeronautics and Astronautics Zhejiang University Hangzhou 310027 China
5. Shenzhen Key Laboratory of Special Functional Materials College of Materials Science and Engineering Shenzhen University Guangdong 518060 China