Graphene has a huge potential as a gas sensor due to the high carrier mobility, large specific surface area, and low electrical noise. Inducing structural defects in graphene lattice has been shown to enhance the capability for sensing gas molecules. However, the mechanism for controlling the sensing of gas molecules on graphene as a function of the type of defects remains unclear. We examined the adsorption of gas molecules (NO<sub>2</sub> and NH<sub>3</sub>) on the defective graphene at the atomic-level. Firstly, Density functional theory (DFT) calculations were performed to clarify the defect formation mechanism by comparing the formation energies of various types of defects. Based on these results, we investigated the adsorption of gas molecules on defective graphenes. Among the defects we examine, vacancy defects were considered a contributing factor to gas molecules sensing performance from the optimized geometries, energetics, and charge transfer analysis. Furthermore, the effects of gold cluster on graphene was also studied for controlling the vacancy defects. Developing defects in graphene is important for high-sensitivity gas sensor. Our results will provide an insight into the prospective materials for gas sensor based on the graphene.

Effects of defective graphene on the enhanced gas sensing: A density functional theory study

251st National Meeting (2016)

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