Local transport measurements on epitaxial graphene

TL;DR

This study uses local transport measurements with a four-tip STM/SEM to analyze the transport regimes of epitaxial graphene on SiC(0001), revealing Anderson localization and diffusive transport without significant strain effects.

Contribution

It introduces a method combining local structure imaging with spatially resolved transport measurements to characterize transport regimes in epitaxial graphene.

Findings

Identification of Anderson localization and diffusive transport regimes.

Confirmation that nano-sized contacts do not induce significant strain.

Correlation between local structure and transport properties.

Abstract

Growth of large-scale graphene is still accompanied by imperfections. By means of a four-tip STM/SEM the local structure of graphene grown on SiC(0001) was correlated with scanning electron microscope images and spatially resolved transport measurements. The systematic variation of probe spacings and substrate temperature has clearly revealed two-dimensional transport regimes of Anderson localization as well as of diffusive transport. The detailed analysis of the temperature dependent data demonstrates that the local on-top nano-sized contacts do not induce significant strain to the epitaxial graphene films.