Chemical Behavior of Bilayer Graphene

  • Author: Veronika Belusa
  • Published: 26 December 2013
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA
  • Source / Publisher: Journal of the American Chemical Society/American Chemical Society (ACS)
  • Associated Societies: American Chemical Society (ACS), USA
thumbnail image: Chemical Behavior of Bilayer Graphene

Its electric-field-controllable band gap makes bilayer graphene increasingly attractive for electronic applications. Bilayer graphene is significantly less chemically reactive than monolayer graphene. Therefore, it is challenging to study its chemistry in detail.

Michael S. Strano and colleagues, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA, have studied the covalent and noncovalent organic functionalization of bilayer graphene in an electrochemical reaction scheme with aryl diazonium salts.

They found that covalent functionalization at high chemical conversion leads to distinct changes in the Raman spectrum. The broadening and shift in the position of the split G peak into G+ and G components – whose relative positions and intensities change with the degree of functionalization – reflect changes in the effective electric field perpendicular to the bilayer graphene surface as well as the presence of disorder, particularly in the broadening of the G+ peak.
Changes in the 2D peak indicate the effects of doping and disorder. The team found that, in particular, the broadening of the 2D22 and 2D21 components indicate covalent functionalization. The decrease in intensity of the 2D11 and 2D12 peaks correspond to doping.
Conductive atomic force microscopy (cAFM) images show that the noncovalent portions of the functionalization can be removed from the bilayer surface with a combination of mechanical cleaning and current annealing. It also shows that the covalently functionalized region is spatially inhomogeneous in its conductivity.

With this the researchers provide a set of spectroscopic markers for distinguishing covalent and noncovalent chemical functionalization of bilayer grapheme.

Article Views: 2559

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

Bookmark and Share

Most Read

If you would like to reuse any content, in print or online, from, please contact us first for permission. more

CONNECT: on Facebook on Twitter on YouTube on LinkedIn Sign up for our free newsletter

A product of ChemPubSoc Europe (16 European Chemical Societies)and Wiley-VCH