Work

Excitonic Effects on the Optical Response of Graphene and Bilayer Graphene

Year: 2009

Type: article

Abstract: We present first-principles calculations of many-electron effects on the optical response of graphene, bilayer graphene, and graphite employing the GW-Bethe Salpeter equation approach. We find that resonant excitons are formed in these two-dimensional semimetals. The resonant excitons give rise to a prominent peak in the absorption spectrum near 4.5 eV with a different line shape and significantly redshifted peak position from those of an absorption peak arising from interband transitions in an independent quasiparticle picture. In the infrared regime, our calculated optical absorbance per graphene layer is approximately a constant, 2.4%, in agreement with recent experiments; additional low frequency features are found for bilayer graphene because of band structure effects.

Source: Physical Review Letters

DOI: 10.1103/physrevlett.103.186802

Authors: Li Yang, Jack Deslippe, Cheol-Hwan Park, Marvin L. Cohen, Steven G. Louie

Institutions: Lawrence Berkeley National Laboratory, University of California, Berkeley

Language: English

Topic: Graphene research and applications

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, U.S. Department of Energy, Office of Science