We show that graphene deposited on a substrate has a non-negligible density of atomic scale defects. This is evidenced by a previously unnoticed D peak in the Raman spectra with intensity of about 1% with respect to the G peak. We evaluated the effect of such impurities on electron transport by mimicking them with hydrogen adsorbates and measuring the induced changes in both mobility and Raman intensity. If the intervalley scatterers responsible for the D peak are monovalent, their concentration is sufficient to account for the limited mobilities achievable in graphene on a substrate.
@article{arxiv.1003.0202,
title = {On resonant scatterers as a factor limiting carrier mobility in graphene},
author = {Z. H. Ni and L. A. Ponomarenko and R. R. Nair and R. Yang and S. Anissimova and I. V. Grigorieva and F. Schedin and Z. X. Shen and E. H. Hill and K. S. Novoselov and A. K. Geim},
journal= {arXiv preprint arXiv:1003.0202},
year = {2010}
}
Comments
version 2: several comments are taken into account and refs added