1. State
Key Laboratory on Integrated Optoelectronics, College of Electronic
Science and Engineering, Jilin University, Changchun 130012, China
2. Department
of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
3. Department
of Chemistry and Physics, Louisiana State University, Shreveport, Louisiana 71115, United States
4. The
Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau