Department of Physics and Astronomy: Publications and Other Research

Evgeny Tsymbal Publications
ORCID IDs
Tsymbal http://orcid.org/0000-0002-6728-5531
Paudel https://orcid.org/0000-0002-9952-9435
Document Type
Article
Date of this Version
1-27-2016
Citation
Applied Physics Letters (2016) 108: 041907
doi: 10.1063/1.4940910
Abstract
The effect of nitrogen doping on the phonon spectra of graphene is analyzed. In particular, we employ first-principles calculations and scanning Raman analysis to investigate the dependence of phonon frequencies in graphene on the concentration of nitrogen dopants. We demonstrate that the G phonon frequency shows oscillatory behavior as a function of nitrogen concentration. We analyze different mechanisms which could potentially be responsible for this behavior, such as Friedel charge oscillations around the localized nitrogen impurity atom, the bond length change between nitrogen impurity and its nearest neighbor carbon atoms, and the long-range interactions of the nitrogen point defects. We show that the bond length change and the long range interaction of point defects are possible mechanisms responsible for the oscillatory behavior of the G frequency as a function of nitrogen concentration. At the same time, Friedel charge oscillations are unlikely to contribute to this behavior.
Comments
Copyright 2016, AIP Publishing. Used by permission