Functional carbon and silicon monolayers in biphenylene network

Abstract

We investigated the effects of vacancy, void, substitutional impurity, isolated adsorption of selected adatoms, and their patterned coverage on the physical and chemical properties of metallic carbon and silicon monolayers in a biphenylene network. These monolayers can acquire diverse electronic and magnetic properties to become more functional depending on the repeating symmetry, size of the point defects, and on the type of adsorbed adatoms. While a carbon monovacancy attains a local magnetic moment, its void can display closed edge states with interesting physical effects. Adsorbed light-transition or rare-earth metal atoms attribute magnetism to these monolayers. The opening of a gap in the metallic density of states, which depends on the pattern and density of adsorbed hydrogen, oxygen, and carbon adatoms, can be used as the band gap engineering of these two-dimensional materials. The energy barriers against the passage of oxygen atoms through the centers of hexagon and octagon rings are investigated, and the coating of the active surfaces with carbon monolayers is exploited as a means of protection against oxidation. We showed that the repulsive forces exerting even at distant separations between two parallel, hydrogenated carbon monolayers in a biphenylene network can lead to the superlow friction features in their sliding motion. All these results obtained from the calculations using the density functional theory herald critical applications.