Liam Britnell, Roman V. Gorbachev, Rashid Jalil, Branson D. Belle, Fred Schedin, Mikhail I. Katsnelson, Laurence Eaves, Sergey V. Morozov, Alexander S. Mayorov, Nuno M. R. Peres, Antonio H. Castro Neto, Jon Leist, Andre K. Geim, Leonid A. Ponomarenko, Kostya S. Novoselov
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.
View original:
http://arxiv.org/abs/1202.0735
No comments:
Post a Comment