The environment of graphene probed by electrostatic force microscopy

TL;DR

This study uses electrostatic force microscopy to investigate the electrostatic environment of graphene, revealing the presence of residues and water molecules that can significantly influence its electrical properties.

Contribution

It provides direct nanoscale measurements of residues and water molecules on graphene, highlighting their potential impact on device performance.

Findings

Detection of electric dipoles from residues and water molecules

Water molecules form a dipole layer generating strong electric fields

Water significantly modifies graphene's electrical properties

Abstract

We employ electrostatic force microscopy to study the electrostatic environment of graphene sheets prepared with the micro-mechanical exfoliation technique. We detect the electric dipole of residues left from the adhesive tape during graphene preparation, as well as the dipole of water molecules adsorbed on top of graphene. Water molecules form a dipole layer that can generate an electric field as large as 10^9 V/m. We expect that water molecules can significantly modify the electrical properties of graphene devices.