Authors:P. Neumann, Z. Horváth, P. Nemes-Incze, G. Molnár, G. Vértesy and L. Biró
We studied the electrical transport properties of indium contacted graphene, few layer graphite (FLG) and bulk graphite samples under ambient conditions. Some of the contacted samples showed nonlinear transport characteristics. The initial electrical properties of the samples were changed reversibly by light illumination and irreversibly by argon ion irradiation. Ion irradiation modified the nonlinear I–V characteristics to quasi-linear ones in many cases. The resistance of a graphene sample showed positive temperature coefficient.