Mechanical cleaning of graphene

TL;DR

This paper demonstrates that mechanical cleaning using contact mode AFM effectively removes residues from graphene, significantly enhancing its electronic properties, including high charge carrier mobility in dual-gated bilayer graphene transistors.

Contribution

It introduces a mechanical cleaning method for graphene that improves electronic quality without chemical treatments.

Findings

Mechanical cleaning removes fabrication residues effectively.

Improved charge carrier mobility up to ~36,000 cm2/Vs.

Enhanced electronic performance of graphene devices.

Abstract

Contamination of graphene due to residues from nanofabrication often introduces background doping and reduces charge carrier mobility. For samples of high electronic quality, post-lithography cleaning treatments are therefore needed. We report that mechanical cleaning based on contact mode AFM removes residues and significantly improves the electronic properties. A mechanically cleaned dual-gated bilayer graphene transistor with hBN dielectrics exhibited a mobility of ~36,000 cm2/Vs at low temperature.