Potential distribution in functionalized graphene devices probed by Kelvin probe force microscopy

Abstract

Kelvin probe force microscopy was used to study the impact of contacts and topography on the local potential distribution on contacted, individual functionalized graphene sheets (FGS) deposited on a SiO2/Si substrate. Negligible contact resistance is found at the graphene/Ti interface and a graphene resistance of 2.3 kΩ is extracted for a single sheet with sub-µm size. Pronounced steps in the topography, which we attribute to a variation of the spacing between graphene and substrate, result in a significant change of the local resistivity.