1. School of Material Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
2. Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620, P.R. China
3. Department of Food Science and Human Nutrition, University of Illinois at Urbana—Champaign, Urbana, Illinois 61801, United States
4. Department of Applied Physics, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing 400044, P.R. China
5. Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, P.R. China