Is graphene on copper doped? (pages 643–646)
Alexander J. Marsden, Maria-Carmen Asensio, José Avila, Pavel Dudin, Alexei Barinov, Paolo Moras, Polina M. Sheverdyaeva, Thomas W. White, Ian Maskery, Giovanni Costantini, Neil R. Wilson and Gavin R. Bell
Version of Record online: 22 JUL 2013 | DOI: 10.1002/pssr.201307224
Using nano-spot angle-resolved photoemission spectroscopy (ARPES) it is shown that graphene grown on low-cost copper foil is undoped with an ideal gapless band structure, even after air exposure. The figure shows nano-ARPES of a Dirac cone “slice” after annealing in vacuum. At 200 °C the band structure is that of pristine undoped graphene. However, annealing to 500 °C induces a gap and doping, and the authors explore the possible mechanisms.