Title

Effects Of Layer Stacking On The Combination Raman Modes In Graphene

Keywords

combination; double resonance; graphene; Raman; spectroscopy

Abstract

We have observed new combination modes in the range from 1650 to 2300 cm-1 in single-(SLG), bi-, few-layer and incommensurate bilayer graphene (IBLG) on silicon dioxide substrates. A peak at ∼1860 cm -1 (iTALO-) is observed due to a combination of the in-plane transverse acoustic (iTA) and the longitudinal optical (LO) phonons. The intensity of this peak decreases with increasing number of layers and this peak is absent for bulk graphite. The overtone of the out-of-plane transverse optical (oTO) phonon at ∼1750 cm-1, also called the M band, is suppressed for both SLG and IBLG. In addition, two previously unidentified modes at ∼2200 and ∼1880 cm-1 are observed in SLG. The 2220 cm-1 (1880 cm-1) mode is tentatively assigned to the combination mode of in-plane transverse optical (iTO) and TA phonons (oTO+LO phonons) around the K point in the graphene Brillouin zone. Finally, the peak frequency of the 1880 (2220) cm-1 mode is observed to increase (decrease) linearly with increasing graphene layers. © 2011 American Chemical Society.

Publication Date

3-22-2011

Publication Title

ACS Nano

Volume

5

Issue

3

Number of Pages

1594-1599

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1021/nn1031017

Socpus ID

79952939141 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/79952939141

This document is currently not available here.

Share

COinS