1. Department of Chemical and Biological Engineering, Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology, William Mong Institute of Nano Science and Technology, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, 999077, P. R. China
2. Department of Applied Physics, The Hong Kong Polytechnic University, Hunghom, Kowloon 999077, Hong Kong
3. State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, Institute of New Energy, China University of Petroleum (East China), Qingdao 266580, P. R. China
4. Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 Cass Ave, Lemont, IL 60439, USA
5. ULVAC-PHI, Inc., Analytical Laboratory, 2500 Hagisono, Chigasaki, Kanagawa 253-8522, Japan
6. Materials and Process Simulation Center (MSC), MC 139-74, California Institute of Technology, Pasadena, CA, 91125, USA