Berlin 2015 – scientific programme
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O: Fachverband Oberflächenphysik
O 21: Graphene: Growth & Intercalation
O 21.6: Talk
Tuesday, March 17, 2015, 11:45–12:00, MA 041
Quantum interference on the doped graphene/SiC systems — •Mykola Telychko1, Pablo Merino2, Pingo Mutombo1, Martin Ondraček1, Prokop Hapala1, Oleksandr Stetsovych1, Martin Švec1, and Pavel Jelínek1 — 1Institute of Physics ASCR, Cukrovarnicka 10, Praha, Czech Republic — 2Max Planck Institute for Solid State Research, Heisenberg Strasse 1, 705669 Stuttgart
We report methodology for co-doping of epitaxial graphene grown on the SiC(0001) substrate by boron and nitrogen atoms. Nitrogen doping was achieved using direct nitrogen ion implantation into the graphene lattice and subsequent thermal stabilization. Boron doping was achieved by introducing the additional source of boron atoms during growth process of the graphene/SiC(0001).
Atomically-resolved low-temperature STM/AFM measurements of well-defined single substitutional nitrogen and boron dopants reveal that nitrogen dopants in graphene lattice feature a strong destructive quantum interference effect, tunable by changing the tip-sample separation. The current dependence on the tip position is successfully modelled by DFT and STM simulations for the both types of dopants. Absence of the destructive interference over the boron dopants allows clear chemical discrimination between the N and B atoms.