1. Department of Chemistry, and the Materials Research Center (MRSEC), Northwestern University, Evanston, Illinois 60208, USA
2. Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
3. Tianjin Key Laboratory of Molecular Optoelectronic Sciences (TJ-MOS), Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, P. R. China
4. Institute of Organic and Polymeric Materials, and Research and Development Center for Smart Textile, National Taipei University of Technology, Taipei 106, Taiwan
5. Department of Material Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA
6. Flexterra Corporation, Skokie, Illinois 60077, USA