1. Centre for Organic Electronics, University of Newcastle, University Drive, Callaghan New South Wales 2308, Australia
2. Department of Physics, University of Bath, Bath BA2 7AY, United Kingdom
3. Flinders Institute for Nanoscale Science and Technology, Flinders University, Sturt Road, Bedford Park, Adelaide, South Australia 5042, Australia
4. Laboratoire de Chimie des Polymères Organiques (LCPO), University of Bordeaux, UMR 5629, B8 Allée Geoffroy Saint Hilaire, 33615 Pessac Cedex, France
5. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States