Effect of ambient on the resistance fluctuations of graphene

TL;DR

This study investigates how different chemical environments influence low frequency resistance fluctuations in graphene transistors, revealing a method to quantify adsorption energies and proposing a highly sensitive chemical sensor based on noise measurements.

Contribution

It introduces a novel noise-based method to determine chemical adsorption energies on graphene and demonstrates the potential for highly sensitive chemical sensing.

Findings

Resistance noise shape depends on adsorption-desorption energetics.

Noise magnitude is highly sensitive to chemical species and concentration.

Proposes a noise-based graphene sensor with high sensitivity and specificity.

Abstract

In this letter we present the results of systematic experimental investigations of the effect of different chemical environments on the low frequency resistance fluctuations of single layer graphene field effect transistors (SLG-FET). The shape of the power spectral density of noise was found to be determined by the energetics of the adsorption-desorption of molecules from the graphene surface making it the dominant source of noise in these devices. We also demonstrate a method of quantitatively determining the adsorption energies of chemicals on graphene surface based on noise measurements. We find that the magnitude of noise is extremely sensitive to the nature and amount of the chemical species present. We propose that a chemical sensor based on the measurement of low frequency resistance fluctuations of single layer graphene field effect transistor devices will have extremely high sensitivity, very high specificity, high fidelity and fast response times.