Detection of CO using a graphene-island-based single-electron transistor

Graphene is a two-dimensional layered nanocrystal which can be used in sensing due to its large surface-to-volume ratio. It has immense potential for future nanoelectronic and spintronic applications. Here, the authors investigated the operational behaviour and performance of a graphene-island single-electron transistor (SET) device using first-principles-based calculations. The electrostatic behaviour was primarily controlled by the gate-island coupling with negligible contribution of electrostatic polarization. It was found that the highest occupied molecular orbital–lowest unoccupied molecular orbital energy gap and the density of states of the graphene layer stay the same on adsorption of a carbon monoxide (CO) molecule onto it, within the SET. The charge-stability diagram can be used for the identification of the presence of a carbon monoxide molecule within an SET using the line scans taken as a function of gate voltage and source-drain bias, for the adsorbed and unadsorbed scenarios.