We have investigated antidot lattices, which were prepared on exfoliated graphene single layers via electron-beam lithography and ion etching, by means of scanning Raman spectroscopy. The peak positions, peak widths and intensities of the characteristic phonon modes of the carbon lattice have been studied systematically in a series of samples. In the patterned samples, we found a systematic stiffening of the G band mode, accompanied by a line narrowing, while the 2D mode energies are found to be linearly correlated with the G mode energies. We interpret this as evidence for p-type doping of the nanostructured graphene.
@article{arxiv.1006.2067,
title = {Scanning Raman spectroscopy of graphene antidot lattices: Evidence for systematic p-type doping},
author = {S. Heydrich and M. Hirmer and C. Preis and T. Korn and J. Eroms and D. Weiss and C. Schüller},
journal= {arXiv preprint arXiv:1006.2067},
year = {2011}
}