Transport measurements have revealed several exotic electronic properties of graphene. The possibility to influence the electronic structure and hence control the conductivity by adsorption or doping with adatoms is crucial in view of electronics applications. Here, we show that in contrast to expectation, the conductivity of graphene increases with increasing concentration of vacancy defects, by more than one order of magnitude. We obtain a pronounced enhancement of the conductivity after insertion of defects by both quantum mechanical transport calculations as well as experimental studies of carbon nano-sheets. Our finding is attributed to the defect induced mid-gap states, which create a region exhibiting metallic behavior around the vacancy defects. The modification of the conductivity of graphene by the implementation of stable defects is crucial for the creation of electronic junctions in graphene-based electronics devices.
@article{arxiv.0905.1346,
title = {Conductivity engineering of graphene by defect formation},
author = {S. H. M. Jafri and Karel Carva and Erika Widenkvist and Tobias Blom and Biplab Sanyal and Jonas Fransson and Olle Eriksson and Ulf Jansson and Helena Grennberg and Olof Karis and R. Quinlan and B. C. Holloway and Klaus leifer},
journal= {arXiv preprint arXiv:0905.1346},
year = {2010}
}