1. School
of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332, United States
2. School
of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic
Drive, Atlanta, Georgia 30332, United States
3. Graduate
School of EEWS, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
4. Jiangsu
Key Laboratory of Advanced Laser Materials and Devices, School of
Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China
5. Department
of Electronic Engineering, The Chinese University of Hong Kong, Shanti, Hong Kong