Exceptionally large migration length of carbon and topographically-facilitated self-limiting molecular beam epitaxial growth of graphene on hexagonal boron nitride
Plaut, AS; Wurstbauerb, U; Wang, S; et al.Levy, AL; Fernandes dos Santos, L; Wang, L; Pfeiffer, LN; Watanabe, K; Taniguchi, T; Dean, CR; Hone, J; Pinczuk, A; Garcia, JM
Date: 18 December 2016
Article
Journal
Carbon
Publisher
Elsevier
Publisher DOI
Abstract
We demonstrate growth of single-layer graphene (SLG) on hexagonal boron nitride (h-BN) by
molecular beam epitaxy (MBE), only limited in area by the finite size of the h-BN flakes. Using
atomic force microscopy and micro-Raman spectroscopy, we show that for growth over a wide range
of temperatures (500◦C – 1000◦C) the deposited carbon ...
We demonstrate growth of single-layer graphene (SLG) on hexagonal boron nitride (h-BN) by
molecular beam epitaxy (MBE), only limited in area by the finite size of the h-BN flakes. Using
atomic force microscopy and micro-Raman spectroscopy, we show that for growth over a wide range
of temperatures (500◦C – 1000◦C) the deposited carbon atoms spill off the edge of the h-BN flakes.
We attribute this spillage to the very high mobility of the carbon atoms on the BN basal plane,
consistent with van der Waals MBE. The h-BN flakes vary in size from 30 µm to 100 µm, thus
demonstrating that the migration length of carbon atoms on h-BN is greater than 100 µm. When
sufficient carbon is supplied to compensate for this loss, which is largely due to this fast migration of
the carbon atoms to and off the edges of the h-BN flake, we find that the best growth temperature
for MBE SLG on h-BN is ∼950◦C. Self-limiting graphene growth appears to be facilitated by
topographic h-BN surface features: We have thereby grown MBE self-limited SLG on an h-BN
ridge. This opens up future avenues for precisely tailored fabrication of nano- and hetero-structures
on pre-patterned h-BN surfaces for device applications.
Physics and Astronomy
Faculty of Environment, Science and Economy
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