@article{3a5892aa5faa455dad7c7077b3300ef1,
title = "Modification of the G-phonon mode of graphene by nitrogen doping",
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.",
author = "Lukashev, {Pavel V.} and Liuyan Zhao and Paudel, {Tula R.} and Theanne Schiros and Noah Hurley and Tsymbal, {Evgeny Y.} and Aron Pinczuk and Abhay Pasupathy and Rui He",
note = "Funding Information: This work was supported by the National Science Foundation (NSF) through the summer programs of the Nebraska Materials Research Science and Engineering Center (Grant No. DMR-1420645). R.H. acknowledges the support of the American Chemical Society Petroleum Research Fund (Grant No. 53401-UNI10) and the NSF (Grant No. DMR-1410496). P.V.L. acknowledges the support of the UNI Faculty Summer Fellowship. Computations were performed at the University of Nebraska Holland Computing Center and at the computer facilities of the University of Northern Iowa (UNI). Synchrotron measurements performed by TS to determine the atomic concentration of nitrogen were supported by the NSF MRSEC program through Columbia in the Center for Precision Assembly of Superstratic and Superatomic Solids(DMR-1420634). Publisher Copyright: {\textcopyright} 2016 AIP Publishing LLC.",
year = "2016",
month = jan,
day = "25",
doi = "10.1063/1.4940910",
language = "English",
volume = "108",
journal = "Applied Physics Letters",
issn = "0003-6951",
number = "4",
}