Effect of electron-beam irradiation on graphene field effect devices

TL;DR

This study investigates how 30 keV electron-beam irradiation affects the electronic properties of graphene and GFETs, revealing doping effects, mobility reduction, and the impact of device suspension on damage.

Contribution

It provides new insights into radiation-induced changes in graphene's electronic transport properties and the differences between supported and suspended devices under electron-beam exposure.

Findings

Electron beam causes negative shifts in charge-neutral point due to n-doping.

Electron beam decreases carrier mobility and minimum conductivity.

Suspended graphene shows reduced CNP shift, indicating less doping effect.

Abstract

Electron beam exposure is a commonly used tool for fabricating and imaging graphene-based devices. Here we present a study of the effects of electron-beam irradiation on the electronic transport properties of graphene and the operation of graphene field-effect transistors (GFET). Exposure to a 30 keV electron-beam caused negative shifts in the charge-neutral point (CNP) of the GFET, interpreted as due to n-doping in the graphene from the interaction of the energetic electron beam with the substrate. The shift of the CNP is substantially reduced for suspended graphene devices. The electron beam is seen to also decrease the carrier mobilities and minimum conductivity, indicating defects created in the graphene. The findings are valuable for understanding the effects of radiation damage on graphene and for the development of radiation-hard graphene-based electronics.