Regensburg 2016 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 9: Graphene: Structure and Dynamics
(Joint session of DS, DY, HL, MA, O and TT organized by O)

TT 9.9: Talk

Monday, March 7, 2016, 12:45–13:00, H24

Origins of contact resistance in graphene-metal edge-contacts — •Bernhard Kretz¹, Christian Søndergaard Pedersen², Daniele Stradi², Aran Garcia-Lekue^1,3, and Mads Brandbyge² — ¹Donostia International Physics Center, E-20018 San Sebastian, Spain — ²Center for Nanostructured Graphene, DTU Nanotech, Tech. Uni. of Denmark, DK-2800 Kongens Lyngby, Denmark — ³IKERBASQUE, Basque Foundation for Science, E-48013 Bilbao, Spain

The transport properties of graphene-metal contacts play an important role in the design of graphene-based devices. Recent studies demonstrate the advantages of the edge-contact geometry over conventional surface contacts.[1,2] However, significantly different conclusions are reached regarding the influence of the metal on the conductance properties of edge-contacts: while simulations indicate that the contact resistance is of the same order of magnitude for different metals,[2] experiments reveal a strong metal-dependence.[1] The possible origins of these discrepancies are explored by studying the transport properties of graphene edge-contacts with different metals, different edge conformations, terminations and adsorption distances. We employ a density functional theory (DFT) based non-equilibrium Green-function (NEGF) approach, using the TranSIESTA code. Our results will offer insights towards a better understanding of the conductance properties of graphene-metal contacts deviating from ideal interfaces.

[1] Wang et al. Science 342, 2013; Chu et al. ACS Nano 8, 2014

[2] Matsuda et al., J. Phys. Chem. C 114, 2010