Capacitive Imaging of Graphene Flakes on SiO2 Substrate

We used scanning capacitance microscopy (SCM) for the local electrical imaging of graphene flakes on a SiO2 substrate. As a result of analyzing the dependence of the SCM measurements on the area of thin graphite nanoislands together with the observed difference in contrast of SCM images related to the graphene layer's thickness, we have concluded that the SCM measurements can selectively image high-conductivity few-layer graphene (FLG) flakes on an insulating substrate without having to fabricate external electrical contacts on the graphene. Our technique is a simple way to explore the conductive properties of low-dimensional systems on an insulating substrate with nanoscale resolution. (C) 2011 The Japan Society of Applied Physics