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Phonon and structural changes in deformed Bernal stacked bilayer graphene
Otakar Frank1, Milan Bouša, Ibtsam Riaz
1J. Heyrovsky Institute of Physical Chemistry of the AS CR, v.v.i., Prague 8, Czech Republic. otakar.frank@jh-inst.cas.cz
Nano Letters
|December 15, 2011
Summary
This study uses Raman spectroscopy to examine bilayer graphene under tension. Inhomogeneous stress can break symmetry, offering a new way to engineer the band gap for electronic applications.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Bilayer graphene exhibits unique electronic properties.
- Uniaxial tension is a method to tune material characteristics.
- Understanding stress distribution is crucial for advanced materials.
Purpose of the Study:
- To investigate the effects of uniaxial tension on Bernal bilayer graphene using Raman spectroscopy.
- To explore phenomena arising from inhomogeneous stress distribution.
- To assess the potential for band gap engineering.
Main Methods:
- Raman spectroscopy was employed to analyze Bernal bilayer graphene flakes.
- Uniaxial tension was applied to the graphene samples.
- Spectroscopic data was analyzed to understand stress-strain relationships and symmetry changes.
Main Results:
- Observed mechanical behavior under even strain across layers.
- Identified phenomena linked to inhomogeneous stress distribution.
- Demonstrated removal of inversion symmetry in bilayer graphene due to uneven strain.
Conclusions:
- Inhomogeneous stress in bilayer graphene under tension can break inversion symmetry.
- This symmetry breaking offers a novel approach for band gap engineering.
- Potential for creating tunable electronic properties in graphene-based devices.
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