2012/02/03 by Liam Britnell, Roman V. Gorbachev, Rashid Jalil +12 · 4 citations
Physics and Astronomy · #cond-mat.mes-hall
paper · pdf · doi:10.1021/nl3002205
published as Nano Lett., 2012, 12 (3), pp 1707-1710 · 7 pages, 5 figures
arxiv created 2012/02/03 · arxiv updated 2012/03/21
We investigate the electronic properties of heterostructures based on ultrathin hexagonal boron nitride (h-BN) crystalline layers sandwiched between two layers of graphene as well as other conducting materials (graphite, gold). The tunnel conductance depends exponentially on the number of h-BN atomic layers, down to a monolayer thickness. Exponential behaviour of I-V characteristics for graphene/BN/graphene and graphite/BN/graphite devices is determined mainly by the changes in the density of states with bias voltage in the electrodes. Conductive atomic force microscopy scans across h-BN terraces of different thickness reveal a high level of uniformity in the tunnel current. Our results demonstrate that atomically thin h-BN acts as a defect-free dielectric with a high breakdown field; it offers great potential for applications in tunnel devices and in field-effect transistors with a high carrier density in the conducting channel.