Optical excitations and field enhancement in short graphene nanoribbons

Caterina Cocchi, Deborah Prezzi, Alice Ruini, Enrico Benassi, Marilia J. Caldas, Stefano Corni, Elisa Molinari

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

The optical excitations of elongated graphene nanoflakes of finite length are investigated theoretically through quantum chemistry semiempirical approaches. The spectra and the resulting dipole fields are analyzed, accounting in full atomistic details for quantum confinement effects, which are crucial in the nanoscale regime. We find that the optical spectra of these nanostructures are dominated at low energy by excitations with strong intensity, comprised of characteristic coherent combinations of a few single-particle transitions with comparable weight. They give rise to stationary collective oscillations of the photoexcited carrier density extending throughout the flake and to a strong dipole and field enhancement. This behavior is robust with respect to width and length variations, thus ensuring tunability in a large frequency range. The implications for nanoantennas and other nanoplasmonic applications are discussed for realistic geometries.

Original languageEnglish
Pages (from-to)924-929
Number of pages6
JournalJournal of Physical Chemistry Letters
Volume3
Issue number7
DOIs
Publication statusPublished - 5 Apr 2012
Externally publishedYes

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Quantum chemistry
Nanoribbons
Carbon Nanotubes
Quantum confinement
Graphite
Photoexcitation
Graphene
Carrier concentration
Nanostructures
graphene
dipoles
Geometry
augmentation
flakes
quantum chemistry
excitation
optical spectrum
frequency ranges
oscillations
geometry

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Cocchi, C., Prezzi, D., Ruini, A., Benassi, E., Caldas, M. J., Corni, S., & Molinari, E. (2012). Optical excitations and field enhancement in short graphene nanoribbons. Journal of Physical Chemistry Letters, 3(7), 924-929. https://doi.org/10.1021/jz300164p

Optical excitations and field enhancement in short graphene nanoribbons. / Cocchi, Caterina; Prezzi, Deborah; Ruini, Alice; Benassi, Enrico; Caldas, Marilia J.; Corni, Stefano; Molinari, Elisa.

In: Journal of Physical Chemistry Letters, Vol. 3, No. 7, 05.04.2012, p. 924-929.

Research output: Contribution to journalArticle

Cocchi, C, Prezzi, D, Ruini, A, Benassi, E, Caldas, MJ, Corni, S & Molinari, E 2012, 'Optical excitations and field enhancement in short graphene nanoribbons', Journal of Physical Chemistry Letters, vol. 3, no. 7, pp. 924-929. https://doi.org/10.1021/jz300164p
Cocchi, Caterina ; Prezzi, Deborah ; Ruini, Alice ; Benassi, Enrico ; Caldas, Marilia J. ; Corni, Stefano ; Molinari, Elisa. / Optical excitations and field enhancement in short graphene nanoribbons. In: Journal of Physical Chemistry Letters. 2012 ; Vol. 3, No. 7. pp. 924-929.
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