Electronic and magnetic properties of graphene, silicene and germanene with varying vacancy concentration

Abstract

The experimental realization of two-dimensional materials such as graphene, silicene and germanene has attracted incredible interest ranging from understanding their physical properties to device applications. During the fabrication and processing of these two-dimensional materials, structural defects such as vacancies may be produced. In this work we have systemically investigated the formation energies, electronic and magnetic properties of graphene, silicene and germanene with vacancies in the framework of spin polarized density functional theory. It is found that the magnetic moment of graphene and silicene with vacancies decreases with the increase in the concentration of vacancies. However, germanene remains non-magnetic irrespective of the vacancy concentration. Low-buckled silicene and germanene with vacancies may possess remarkable band gaps, in contrast to planar graphene with vacancies. With the formation of vacancies silicene and germanene demonstrate a transition from semimetal to semiconductor, while graphene turns to be metallic.

First Principles Study of the Ambipolarity in a Germanene Nanoribbon Tunneling Field Effect Transistor

“…Periodic boundary conditions with vacuum layer of approximately 15 Å for each side of the unitcell are employed to prevent undesired image-image interaction. It is worth noting that the vacuum layer size for the AGeNR case is in agreement with the previous works presented in [38,39]. To remove the dangling bond effects on the surface of nanoribbons, edges on both sides were passivated with hydrogen atoms.…”

Magnetic properties of 3d transition metal (Sc–Ni) doped plumbene

“…Two-dimensional (2D) materials, particularly those in group 14, have attracted extensive interest due to their potential in terms of the topological insulating properties, [1][2][3][4][5][6][7][8] the chemical reactivity, 9 the magnetic behavior, 10,11 and the thermal properties. 12 A recently synthesized 2D material, called plumbene [13][14][15][16][17] has generated much attention because it has the largest spin-orbit interaction among all group 14 elements 18 as the magnitude of spin-orbit coupling increases approximately as the fourth power of the effective nuclear charge.…”

Two‐dimensional Silicon‐Carbon Compounds: Structure Prediction and Band Structures

“…In both cases the atoms are arranged in a hexagonal lattice as an atomically thin sheet and the materials can be used, for example, in field‐effect transistors. Both graphene and silicene exhibit an unusual band structure of a semi‐metal with a Dirac point at the Fermi energy, and very high electronic conductivity , . In addition, graphene is highly mechanically stable against distortions in the xy plane.…”