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Graphene and Boron Nitride for Atomically Thin Circuitry

Speaker: 
Jiwoong Park (Cornell University, USA)
Date: 
Wed, 24/10/2012 - 12:00pm to 1:00pm
Location: 
S13-M01-11 (Physics Conference Room)
Event Type: 
Seminars

Abstract


In the past few years, the science and application of graphene, a hexagonal crystal entirely made of carbon atoms, has experienced a revolutionary change, mainly due to the development of large scale growth methods based on chemical vapor deposition (CVD). This enabled production of single-atom-thick conducting films in meter scale. However, it still remains difficult to characterize and process graphene films, while maintaining many of their excellent properties. Namely, the materials science and engineering of graphene is still in its infancy. First, these CVD graphene films are polycrystalline as grown. We recently reported the first atomic-resolution imaging of individual grain boundaries in graphene membranes as well as a dark-field transmission electron microscopy (TEM) technique that rapidly characterizes graphene grain structures. Using these new synthesis, fabrication and TEM characterization methods, our group can now investigate the structure of grain boundaries and probe their effects on the mechanical, electrical, and chemical properties of CVD graphene. In addition, CVD graphene produces bilayer regions with different stacking structures. We showed that the angle dependent interlayer interaction leads to fascinating electrical and mechanical properties of bilayer graphene in different configurations (vertical junctions).
 
More recently, we used some of these newly developed capabilities in order to demonstrate atomically thin circuitry entirely made of graphene (conductor) and hexagonal boron nitride (insulator), which presents exiting new directions for these materials. Our results represent an important step towards developing atomically thin integrated circuitry and enable the fabrication of electrically isolated active and passive elements embedded in continuous, one-atom-thick sheets, which could be manipulated and stacked to form complex devices at the ultimate thickness limit.
 
References
 
[1] M. P. Levendorf, C.-J. Kim, L. Brown, P. Y. Huang, R. W. Havener, D. A. Muller, and J. Park, “Graphene and Boron Nitride Lateral Heterostructures for Atomically Thin Circuitry”, Nature, 488, 627-632 (2012). 
[2] R. W. Havener, H. Zhuang, L. Brown, R. Hennig, and J. Park, “Angle-Resolved Raman Imaging of Interlayer Rotations and Interactions in Twisted Bilayer Graphene”, Nano Letters, 12, 3162-3167 (2012). 
[3] A. W. Tsen, L. Brown, M. P. Levendorf, F. Ghahari, P. Y. Huang, C. S. Ruiz-Vargas, R. W. Havener, D. A. Muller, P. Kim, and J. Park, "Tailoring Electrical Transport across Grain Boundaries in Polycrystalline Graphene", Science, 336, 1143-1146 (2012). 
[4] P. Y. Huang, C. S. Ruiz-Vargas, A. M. van der Zande, W. S. Whitney,  M. P. Levendorf, J. W. Kevek, S. Garg, J. S. Alden, C. J. Hustedt, Y. Zhu, J. Park, P. L. McEuen, D. A. Muller, “Grains and Grain Boundaries in Single-Layer Graphene Atomic Patchwork Quilts,” Nature 469, 389-392 (2011).
 
Speaker's Bio
 
Dr. Jiwoong Park is an associate professor in the Department of Chemistry and Chemical Biology and an executive member of Kavli Institute for Nanoscale Science at Cornell University, with a PhD in physics from the University of California, Berkeley. Before coming to Cornell, he was a Junior Fellow at Rowland Institute at Harvard University. His research interests focus on the electronic and optical properties of nanoscale materials including semiconductor nanowires, carbon nanotubes and graphene. He made contributions on understanding photoelectic and thermoelectric properties of 1D and 2D nanostructures synthesized by his group. Dr. Park is a recipient of NSF CAREER award (2008), Presidential Early Career Awards for Scientists and Engineers (2009) and Alfred P. Sloan Research Fellowship (2010).

 

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