Decoupling and ordering of multilayer graphene on C-face 3C-SiC(111)

We show experimentally that few layergraphene (FLG) grown on the carbon terminated surface (C-face) of 3C-SiC(111) is composed of decoupledgraphene sheets.Landau levelspectroscopy on FLGgraphene is performed using the infrared optical Hall effect. We find thatLandau level transitions in the FLG exhibitpolarization preserving selection rules and the transition energies obey a square-root dependence on themagnetic field strength. These results show that FLG on C-face 3C-SiC(111) behave effectively as a single layergraphene with linearly dispersing bands (Dirac cones) at thegraphene K point. We estimate from theLandau levelspectroscopy an upper limit of the Fermi energy of about 60  meV in the FLG, which corresponds to a carrier density below 2.5 × 1011  cm−2. Low-energy electron diffraction μ-LEED) reveals the presence of azimuthally rotatedgraphene domains with a typical size of ≤200 nm. μ-LEED mapping suggests that the azimuth rotation occurs between adjacent domains within the same sheet rather than vertically in the stack.

Source: Applied Physics Letters - November 14, 2016 Category: Physics Authors: C. Bouhafs, V. Stanishev, A. A. Zakharov, T. Hofmann, P. K ühne, T. Iakimov, R. Yakimova, M. Schubert and V. Darakchieva Source Type: research