Exceptionally large migration length of carbon and topographically-facilitated self-limiting molecular beam epitaxial growth of graphene on hexagonal boron nitride

Journal Article · Sat Apr 01 00:00:00 EDT 2017 · Carbon

DOI:https://doi.org/10.1016/j.carbon.2016.12.031· OSTI ID:1397222

Plaut, Annette S.; Wurstbauer, Ulrich; Wang, Sheng; Levy, Antonio L.; Fernandes dos Santos, Lara; Wang, Lei; Pfeiffer, Loren N.; Watanabe, Kenji; Taniguchi, Takashi; Dean, Cory R.; Hone, James; Pinczuk, Aron; Garcia, Jorge M.

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.

• Research Organization: Energy Frontier Research Centers (EFRC) (United States). Re-Defining Photovoltaic Efficiency Through Molecule Scale Control (RPEMSC)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: SC0001085
• OSTI ID: 1397222
• Journal Information: Carbon, Vol. 114, Issue C; Related Information: RPEMSC partners with Columbia University (lead); Brookhaven National Laboratory; Purdue University; ISSN 0008-6223
• Publisher: Elsevier
• Country of Publication: United States
• Language: English