Atomically thin boron nitride : a tunnelling barrier for graphene devices

• Author(s): Britnell, Liam ; Gorbachev, R. V. ; Jalil, R. ; Belle, B. D. ; Schedin, F. ; Katsnelson, M. I. ; Eaves, L. ; Morozov, S. V. ; Mayorov, Alexander S. ; Peres, N. M. R. ; Castro Neto, A. H. ; Leist, J. ; Geim, A. K. ; Ponomarenko, L. A. ; Novoselov, K. S.
• Date: 2012
• Persistent ID: http://hdl.handle.net/1822/21890
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Graphene
• Document Type: Article
• Language: English

Description

Documento submetido para revisão pelos pares. a publicar em Nano Letters 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.