On the utility of vacancies and tensile strain-induced quality factor enhancement for masssensing using graphene monolayers

Abstract

We have utilized classical molecular dynamics to investigate the mass sensing potential of graphenemonolayers, using gold as the model adsorbed atom. In doing so, we report two key findings.First, we find that while perfect graphene monolayers are effective mass sensors at very low(T < 10 K) temperatures, their mass sensing capability is lost at higher temperatures due to diffusionof the adsorbed atom at elevated temperatures. We demonstrate that even if the quality(Q) factors are significantly elevated through the application of tensile mechanical strain, themass sensing resolution is still lost at elevated temperatures, which demonstrates that highQ-factors alone are insufficient to ensure the mass sensing capability ofgraphene. Second, we find that while the introduction of single vacanciesinto the graphene monolayer prevents the diffusion of the adsorbed atom,the mass sensing resolution is still lost at higher temperatures, again due toQ-factor degradation. We finally demonstrate that if theQ-factors of the graphene monolayers with single vacancies are keptacceptably high through the application of tensile strain, then the highQ-factors, in conjunction with the single atom vacancies to stop the diffusion of the adsorbedatom, enable graphene to maintain its mass sensing capability across a range oftechnologically relevant operating temperatures.