Insights into the Electronic Structure of Oxygen-Functionalized Single- and Bilayer Graphene

We investigate the structural and electrical properties of single-layer (SLG) and bilayer graphene (BLG) exposed to an oxygen plasma. The results of XPS spectroscopy measurements, combined with ab initio calculations of the density of states and electronic band structures, allow us to attribute the change in the properties of SLG and BLG to the presence of oxygen atoms on the lattice surface, in the form of epoxy groups. In detail, a bandgap appears in SLG in the case of oxygen atom densities as high as 50%, whereas BLG retains its semimetallicity. Moreover, the details of the band structure of oxygen-decorated BLG, in the immediate vicinity of the Fermi level, are practically undistinguishable from those of pristine SLG. These results are corroborated by Raman spectroscopy and electrical measurements performed on back-gated, plasma-treated graphene devices. This work represents a step forward in the controlled tailoring of the properties of graphene for electronic applications.

ISBN:978-1-4398-7133-1

Publication year:2011

BOF-keylabel:yes

IOF-keylabel:yes

Authors from:Government, Higher Education