Please use this identifier to cite or link to this item:
|Title:||Second-order overtone and combination raman modes of graphene layers in the range of 1690-2150 cm-1|
|Source:||Cong, C., Yu, T., Saito, R., Dresselhaus, G.F., Dresselhaus, M.S. (2011-03-22). Second-order overtone and combination raman modes of graphene layers in the range of 1690-2150 cm-1. ACS Nano 5 (3) : 1600-1605. ScholarBank@NUS Repository. https://doi.org/10.1021/nn200010m|
|Abstract:||Though graphene has been intensively studied by Raman spectroscopy, in this letter, we report a study of the second-order overtone and combination Raman modes in a mostly unexplored frequency range of 1690-2150 cm-1 in nonsuspended commensurate (AB-stacked), incommensurate (folded) and suspended graphene layers. On the basis of the double resonance theory, four dominant modes in this range have been assigned to (i) the second order out-of-plane transverse mode (2oTO or M band), (ii) the combinational modes of in-plane transverse acoustic mode and longitudinal optical mode (iTA+LO), (iii) in-plane transverse optical mode and longitudinal acoustic mode (iTO+LA), and (iv) longitudinal optical mode and longitudinal acoustic mode (LO+LA). Differing from AB-stacked bilayer graphene or few layer graphene, single layer graphene shows the disappearance of the M band. Systematic analysis reveals that interlayer interaction is essential for the presence (or absence) of the M band, whereas the substrate has no effect on the presence (or absence) of the M band. Dispersive behaviors of these new Raman modes in graphene have been probed by laser excitation energy-dependent Raman spectroscopy. It is found that the appearance of the M band strictly depends on the AB stacking, which could be used as a fingerprint for AB-stacked bilayer graphene. This work expands upon the unique and powerful abilities of Raman spectroscopy to study graphene and provides another effective way to probe phonon dispersion, electron-phonon coupling, and to exploit the electronic band structure of graphene layers. © 2011 American Chemical Society.|
|Source Title:||ACS Nano|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Apr 16, 2018
WEB OF SCIENCETM
checked on Apr 16, 2018
checked on Apr 20, 2018
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.