Adsorption of Noble Gases on Hydrogenated Group IV Monolayers: Stability and Electronic Properties

In this work, the adsorption behaviors of noble gases (He, Ne, Ar, Kr, and Xe) on hydrogenated group IV monolayers (silicene, germanene, and Si0.5Ge0.5 monolayer) were studied using first-principles calculations. The results show that all the noble gases are physisorbed on the hydrogenated monolayers via van der Waals interaction, and the adsorption energy increases with the size of the noble gas atoms owing to the increase in atomic polarizability. Further analysis shows that the interaction between the noble gases and the hydrogenated monolayers is strong enough and most of the adsorbed noble gases are stable at room temperature. Upon adsorption of the noble gases, hydrogenated germanene shows the most dramatic relative change in Fermi level among the hydrogenated group IV monolayers and is most suitable for noble gas sensors. Our results may be useful for the design, fabrication, and application of group IV monolayer-based noble gas absorbers and sensors.