Band Engineering of Graphene, Dr. Paul Bazylewski, Western

Event Date: Thursday, May 26, 2016

Department of Physics & Astronomy
PHYSICS & ASTRONOMY COLLOQUIUM
Dr. Paul Bazylewski

Department of Physics & Astronomy
University of Western Ontario

“Band Engineering of Graphene using Metal Mediated Oxidation”

ABSTRACT

In the study of materials for electronic devices, there is a continuous search for new materials with useful properties such as graphene and graphene-based materials. Research on these materials is widespread for many applications such as manipulation of the band structure of graphene to induce a semiconducting band gap.

The focus of this study is a cobalt nanoparticle-graphene system investigated for the manipulation of the graphene electronic structure. The properties of this system were investigated using various X-ray spectroscopy and surface science techniques. At a low concentration of cobalt, the metal is completely oxidized into primarily CoO, and the graphene is not heavily damaged. Oxide groups form on the graphene surface but are found to be proportional to the cobalt concentration at thicknesses below 1 nm.

Using X-ray spectroscopy, an electronic band gap of up to 0.30 eV is observed in graphene 2p states when cobalt nucleates into nanoparticle islands on the graphene surface. The mechanism of band gap opening is interpreted using electronic structure calculations, showing a contribution from both the oxidation of the graphene itself and the presence of CoO that acts to localize electron charge.

These results have implications for graphene electronics and spintronics where magnetic metals can be used to induce a band gap in graphene that is stable at room temperature and under atmospheric exposure.

Coffee will be available in the Atrium, 2nd floor, at 1:15 p.m.

We look forward to seeing you at the Colloquium! As a courtesy to the speaker and audience, please set your cellphones to “silent” mode. Thanks!

Band Engineering of Graphene, Dr. Paul Bazylewski, Western