Work

Phonon softening and crystallographic orientation of strained graphene studied by Raman spectroscopy

Year: 2009

Type: article

Abstract: We present a systematic study of the Raman spectra of optical phonons in graphene monolayers under tunable uniaxial tensile stress. Both the G and 2D bands exhibit significant red shifts. The G band splits into 2 distinct subbands (G(+), G(-)) because of the strain-induced symmetry breaking. Raman scattering from the G(+) and G(-) bands shows a distinctive polarization dependence that reflects the angle between the axis of the stress and the underlying graphene crystal axes. Polarized Raman spectroscopy therefore constitutes a purely optical method for the determination of the crystallographic orientation of graphene.

Source: Proceedings of the National Academy of Sciences

DOI: 10.1073/pnas.0811754106

Authors: Mingyuan Huang, Hugen Yan, Changyao Chen, Daohua Song, Tony F. Heinz, James Hone

Institution: Columbia University

Language: English

Topic: Graphene research and applications

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: bronze

Funders: National Science Foundation, Defense Advanced Research Projects Agency, Center for Nanoscale Science and Technology

Award: NIRT/SNB: Combined Optical, Electrical, Mechanical, and Thermal Characterization of Individual Nanotubes