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.

Hydrogenated Carbon Monolayer in Biphenylene Network Offers a Potential Paradigm for Nanoelectronic Devices

“…These functional properties are tunable by the coverage of diverse adatoms, by the formation of vacancy and other point defects. 20 Other properties related with C ohs have been reported in recent papers. 21,22 In this study, we show that on a 2D monolayer one can realize a number of crucial electromagnetic device functions.…”

“…Recently, the synthesis of this 2D nonhexagonal, monolayer structure (which consists of the adjacent octagon- ( o ), hexagon- ( h ), and square- ( s ) rings and is specified briefly as C ohs structure in this text) have been realized using different processes. , Even if the 3-fold coordination of atoms is maintained in this new allotrope, the sp 2 -hybridization is deformed. Very recently, we showed that not only the C ohs structure, but also stable ohs monolayers of other group IV elements (Si, Ge), group IV–IV (SiC, GeC, SnC), III–V (BN, BP, BAs, BSb, AlN, AlP, GaN, InN), and II–VI (ZnSe) compounds and their multilayers, as well as 3D periodic ohs crystals, can be regarded a new class of materials like their counterparts in the honeycomb network. − Here, C, Si, and Ge ohs monolayers of group IV elements have been found to be good metals as a consequence of multiple crossing of the Fermi level by p z -bands, in contrast to their Dirac semimetal counterparts in a honeycomb network, namely graphene, silicene, and germanene. − Recent studies on the adsorption of adatoms like H, O, C, Si, F, Ti, and Gd on bare C ohs monolayer have predicted various critical effects on the electronic properties. − In particular, it has been demonstrated that C and Si ohs monolayers can acquire novel magnetic and electronic states. These functional properties are tunable by the coverage of diverse adatoms, by the formation of vacancy and other point defects .…”

Theoretical design of porous dodecagonal germanium carbide (d-GeC) monolayer

“… 19 It should be emphasized that such a porous d-GeC monolayer with semiconducting property is rarely found. However, the structure exists in the form of purely carbon-based structures called biphenylene carbons 20 or graphenylenes. 22 These structures occur in various allotropes with a well-ordered ring composed of 8, 10, or 12 atoms.…”

Structural, mechanical, electronic and optical properties of biphenylene hydrogenation: a first-principles study

“…In addition to the aforementioned hydrogenation and halogenation methods, other researchers have also investigated the effects of doping with O, C, NH 3 , CH, CO, NO 2 , and Si on the electronic properties of biphenylene. 17,33,34 Previous studies have mostly focused on the effects of different doping strategies on the electronic properties of biphenylene, as well as comparisons of different doped configurations for stability. In order to fully utilize the properties of biphenylene for eventual semiconductor technology applications, further theoretical investigation is imperative.…”