Dresden 2017 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 25: Poster: Nitrides
HL 25.4: Poster
Montag, 20. März 2017, 15:00–19:00, P2-OG2
Characterization of epitaxial graphene nanoribbons (GNR) — •Jantje Schommartz1,2, Talieh Ghiasi2, Alexey Kaverzin2, Johannes Aprojanz1, Christoph Tegenkamp1, and Bart J. van Wees2 — 1Institut für Festkörperphysik, Leibniz Universität Hannover, Deutschland — 2Physics of Nanodevices, University of Groningen, Netherlands
Epitaxially grown graphene nanoribbons (GNR) self-assembled on pre-structured SiC nanofacets are recently shown to be single channel ballistic conductor even at room temperature on a length scale greater than ten micrometers [1]. The reported long mean free path, as well as the presence of topologically protected edge states, makes the GNR a subject of intense interest at present. In contrast to GNR, patterned lithographically by etching graphene, epitaxially grown GNR on SiC mesas shows well-defined edge states. In this study, Conductive Atomic Force Microscopy (CAFM) and PeakForce TUNA (PF-TUNA) probe techniques are applied to study the current profile and height profile of both sidewall and natural-step GNR. Compared with the CAFM measurements where the sample and tip are in contact, in the PF-TUNA measurements the sample is oscillating and the tip-sample position is controlled via monitoring the maximum force on the tip which eliminates the lateral forces on the sample. Detection of the electrical current only on the sidewalls and natural steps of the SiC mesa pattern confirms the selective growth of freestanding GNR on SiC nanofacets. [1] Baringhaus et al., Nature 506, 349 (2014)