Regensburg 2013 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 46: Graphene - SiC Substrates and Intercalation (jointly with DS, HL, MA, and O)

TT 46.9: Talk

Wednesday, March 13, 2013, 18:00–18:15, H17

Transfer-free electrical insulation of epitaxial graphene from its metal substrate — Silvano Lizzit¹, Rosanna Larciprete², Paolo Lacovig¹, Matteo Dalmiglio¹, Fabrizio Orlando^3,4, Alessandro Baraldi^3,4, Lauge Gammelgaard⁵, •Lucas Barreto⁶, Marco Bianchi⁶, Edward Perkins⁶, and Philip Hofmann⁶ — ¹Sincrotrone Trieste, Italy — ²CNR-Institute for Complex Systems, Roma, Italy — ³Physics Department and CENMAT, University of Trieste,Italy — ⁴IOM-CNR Laboratorio TASC, Trieste, Italy — ⁵Capres A/S, Lyngby, Denmark — ⁶Institut for Fysik og Astronomi, Interdisciplinary Nanoscience Center (iNANO), Aarhus Universitet Denmark

High-quality, large-area epitaxial graphene can be grown on metal surfaces, but its transport properties cannot be exploited because the electrical conduction is dominated by the substrate. Here we show how to insulate epitaxial graphene from the Ru(0001) surface it is grown on by a step-wise intercalation of silicon and oxygen, and the eventual formation of a SiO₂ layer between the graphene and the metal. The reaction steps are followed by x-ray photoemission spectroscopy. The presence of a SiO₂ layer should insulate the metal from the substrate. In order to verify this, lateral transport measurements were performed using a nano-scale multipoint probe technique. The resistance obtained is substantially higher than expected for a clean ruthenium surface but consistent with that expected for graphene. Moreover, the data suggest two-dimensional electronic transport, as expected for graphene.