Raman Spectroscopy of Lithographically Patterned Graphene Nanoribbons

Beitrag in einer Fachzeitschrift


Details zur Publikation

Autor(en): Ryu S, Maultzsch J, Han MY, Kim P, Brus LE
Zeitschrift: Acs Nano
Verlag: AMER CHEMICAL SOC
Jahr der Veröffentlichung: 2011
Band: 5
Heftnummer: 5
Seitenbereich: 4123-4130
ISSN: 1936-0851


Abstract


Nanometer-scale graphene objects are attracting much research interest because of newly emerging properties originating from quantum confinement effects. We present Raman spectroscopy studies of graphene nanoribbons (GNRs), which are known to have nonzero electronic bandgap. GNRs of width ranging from 15 to 100 nm have been prepared by e-beam lithographic patterning of mechanically exfoliated graphene followed by oxygen plasma etching. Raman spectra of narrow GNRs can be characterized by an upshifted G band and a prominent disorder-related D band originating from scattering at the ribbon edges. The D-to-G band intensity ratio generally Increases with decreasing ribbon width. However, its decrease in width of <25 nm, partly attributed to amorphization at the edges, provides a valuable experimental estimate on D mode relaxation length of <5 nm. The upshift in the G band of the narrowest GNRs can be attributed to confinement effect or chemical doping by functional groups on the GNR edges. Notably, GNRs are much more susceptible to photothermal effects resulting in reversible hole doping caused by atmospheric oxygen than bulk graphene sheets. Finally we show that the 2D band is still a reliable marker in determining the number of layers of GNRs despite its significant broadening for very narrow GNRs.



FAU-Autoren / FAU-Herausgeber

Maultzsch, Janina Prof. Dr.
Lehrstuhl für Experimentalphysik


Autor(en) der externen Einrichtung(en)
Columbia University
Kyung Hee University


Zitierweisen

APA:
Ryu, S., Maultzsch, J., Han, M.Y., Kim, P., & Brus, L.E. (2011). Raman Spectroscopy of Lithographically Patterned Graphene Nanoribbons. Acs Nano, 5(5), 4123-4130. https://dx.doi.org/10.1021/nn200799y

MLA:
Ryu, Sunmin, et al. "Raman Spectroscopy of Lithographically Patterned Graphene Nanoribbons." Acs Nano 5.5 (2011): 4123-4130.

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Zuletzt aktualisiert 2018-08-08 um 05:21