We investigate the dependence of the electrical resistivity of ∼60nm thick single crystalline graphite samples on the defect concentration produced by proton irradiation at very low fluences. We show that the resistivity decreases few percent at room temperature after inducing defects at concentrations as low as ∼0.1ppm due to the increase in the carrier density, in agreement with theoretical estimates. The overall results indicate that the carrier densities measured in graphite are not intrinsic but related to defects and impurities.
@article{arxiv.0905.2945,
title = {On the origin of the electric carrier concentration in graphite},
author = {A. Arndt and D. Spoddig and P. Esquinazi and J. Barzola-Quiquia and T. Butz},
journal= {arXiv preprint arXiv:0905.2945},
year = {2009}
}