New Journal of Physics 14 (2012) 053015
N. García, P. Esquinazi, J. Barzola-Quiquia, and S. Dusari
Abstract
We have studied the resistance of a large number of highly oriented graphite samples with areas ranging from several mm2 to a few μm2 and thickness from 10 nm to several tens of micrometers. The measured resistance can be explained by the parallel contribution of semiconducting graphene layers with low carrier density < 109 cm−2 and the one from metallic-like internal interfaces. The results indicate that ideal graphite with Bernal stacking structure is a semiconductor with a narrow band gap Eg 40 meV.