1. State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials Science and Engineering, The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province, Sun Yat-sen (Zhongshan) University, Guangzhou 510275, People’s Republic of China
2. Department of Physics, College of Science, Shantou University, Shantou 515063, People’s Republic of China
3. Key Lab of Numerical Controlled Technology, Guangdong Polytechnic Normal University, Guangzhou 510635, People’s Republic of China