Atomically thin boron nitride: a tunnelling barrier for graphene devices

• Autor(a) principal: Britnell, Liam
• Data de Publicação: 2012
• Outros Autores: 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.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/21890
• topic: Graphene

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.