Confocal Raman spectroscopy is a versatile, non-invasive investigation tool and a major workhorse for graphene characterization. Here we show that the experimentally observed Raman 2D line width is a measure of nanometer-scale strain variations in graphene. By investigating the relation between the G and 2D line at high magnetic fields we find that the 2D line width contains valuable information on nanometer-scale flatness and lattice deformations of graphene, making it a good quantity for classifying the structural quality of graphene even at zero magnetic field.
@article{arxiv.1406.7771,
title = {Raman spectroscopy as probe of nanometer-scale strain variations in graphene},
author = {Christoph Neumann and Sven Reichardt and Pedro Venezuela and Marc Drögeler and Luca Banszerus and Michael Schmitz and Kenji Watanabe and Takashi Taniguchi and Francesco Mauri and Bernd Beschoten and Slava V. Rotkin and Christoph Stampfer},
journal= {arXiv preprint arXiv:1406.7771},
year = {2017}
}