1. Department of Micro- and Nanotechnology, Technical University of Denmark, Ørsteds Plads 345 B, 2800 Kongens Lyngby, Denmark
2. Center for Nanostructured Graphene (CNG), Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
3. NIL Technology APS, Diplomvej 381, DK-2800 Kongens Lyngby, Denmark
4. Cambridge Graphene Centre, Engineering Department, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, United Kingdom