Detecting the local transport properties and the dimensionality of transport of epitaxial graphene by a multi-point probe approach

TL;DR

This study uses a multi-point probe method to analyze the transport properties and dimensionality of epitaxial graphene layers on SiC, revealing their two-dimensional transport behavior and measuring their room temperature mobilities.

Contribution

It introduces a multi-point probe approach to determine the transport dimensionality and properties of epitaxial graphene layers, providing new insights into their electronic behavior.

Findings

Transport in both MLG and QFBLG is purely two-dimensional.

Room temperature mobility of MLG is approximately 870 cm²/Vs.

Room temperature mobility of QFBLG is approximately 1600 cm²/Vs.

Abstract

The electronic transport properties of epitaxial monolayer graphene (MLG) and hydrogen-intercalated quasi free-standing bilayer graphene (QFBLG) on SiC(0001) are investigated by micro multi-point probes. Using a probe with 12 contacts, we perform four-point probe measurements with the possibility to effectively vary the contact spacing over more than one order of magnitude, allowing us to establish that the transport is purely two-dimensional. Combined with the carrier density obtained by angle-resolved photoemission spectroscopy, we find the room temperature mobility of MLG to be (870+-120)cm2/Vs. The transport in QFBLG is also found to be two-dimensional with a mobility of (1600+-160) cm2/Vs.