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Tunable bands in biased multilayer epitaxial graphene
Michael D Williams1, Duminda K Samarakoon, Dennis W Hess
1Department of Physics and Center for Functional Nanoscale Materials, Clark Atlanta University, Atlanta, Georgia 30314, USA.
Nanoscale
|March 29, 2012
Summary
We investigated multilayer epitaxial graphene
Area of Science:
- Condensed matter physics
- Materials science
- Surface science
Background:
- Multilayer epitaxial graphene exhibits unique electronic properties.
- Understanding electronic band structure is crucial for device applications.
Purpose of the Study:
- To investigate the electronic characteristics of multilayer epitaxial graphene under an electric bias.
- To explore the tunability of electronic band structure via electric field control.
Main Methods:
- Ultraviolet photoemission spectroscopy (UPS) for experimental analysis.
- First-principles density-functional theory (DFT) with van der Waals interactions for theoretical modeling.
Main Results:
- UPS revealed significant variations in electronic density-of-states near the Fermi level.
- DFT calculations showed that applied bias tunes interlayer coupling, altering electronic structure.
- Experimental and theoretical results confirm the correlation between bias, coupling, and band structure.
Conclusions:
- Electric bias controllably tunes the electronic band structure of multilayer epitaxial graphene.
- Rotationally fault-stacked graphene on SiC offers potential for novel electronic device applications.
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