1. Department of Physics, Chemistry and BiologyLinköping University 58183 Linköping Sweden
2. Laboratory of Organic Electronics, Department of Science and TechnologyLinköping University 60174 Norrköping Sweden
3. Department of ChemistryStanford University Stanford CA 94305-5080 USA
4. Department of Chemistry'Ångström'Uppsala University Lägerhyddsvägen 1 75120 Uppsala Sweden
5. Graphensic AB Teknikringen 1F SE-58330 Linköping Sweden