1. The George and Josephine Butler Polymer Research Laboratory, Department of Chemistry and Center for Macromolecular Science and Engineering, University of Florida, Gainesville, Florida 32611-7200, United States
2. School of Electrical and Computer Engineering and Center for Organic Photonics and Electronics, Georgia Institute of Technology, 777 Atlantic Drive, Atlanta, Georgia 30332, United States
3. Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611, United States