Tuning the graphene work function by electric field effect

TL;DR

This paper demonstrates how the work function of graphene can be tuned using electric fields, with measurements made via SKPM, enabling better control and understanding of contact resistance in graphene devices.

Contribution

It introduces a method to adjust graphene's work function through electric field effect and uses SKPM to measure contact resistance at the electrode-graphene interface.

Findings

Work function of graphene can be tuned by gate voltage.

SKPM provides reliable surface potential measurements.

Contact resistance can be assessed using SKPM mapping.

Abstract

We report variation of the work function for single and bi-layer graphene devices measured by scanning Kelvin probe microscopy (SKPM). Using the electric field effect, the work function of graphene can be adjusted as the gate voltage tunes the Fermi level across the charge neutrality point. Upon biasing the device, the surface potential map obtained by SKPM provides a reliable way to measure the contact resistance of individual electrodes contacting graphene.