Electronic Properties of Oxidized Graphene: Effects of Strain and an Electric Field on Flat Bands and the Energy Gap

Abstract

A multiscale modeling and simulation approach, including first-principles calculations, ab initio molecular dynamics simulations, and a tight binding approach, is employed to study band flattening of the electronic band structure of oxidized monolayer graphene. The width of flat bands can be tuned by strain, the external electric field, and the density of functional groups and their distribution. A transition to a conducting state is found for monolayer graphene with impurities when it is subjected to an electric field of ∼1.0 V/Å. Several parallel impurity-induced flat bands appear in the low-energy spectrum of monolayer graphene when the number of epoxy groups is changed. The width of the flat band decreases with an increase in tensile strain but is independent of the electric field strength. Here an alternative and easy route for obtaining band flattening in thermodynamically stable functionalized monolayer graphene is introduced. Our work discloses a new avenue for research on band flattening in monolayer graphene.

Enhanced sensing performance of armchair stanene nanoribbons for lung cancer early detection using an electric field

“…The flat band is observed when the system is doped, or a strain or electric field is applied to the system. 41,42 Flat bands are energy-independent and lead to a high density of states near the Fermi energy. The band structure of 10-ASnNR in the presence of positive and negative directions of transverse electric fields is depicted in Fig.…”

Multiband flattening and linear Dirac band structure in graphene with impurities

“…There are different ways to manipulate electronic band structure and introduce a FB into 2D-materials, such as by introducing defects [14] and impurities such as hydrogen (H) [15][16][17], oxygen (O) [18,19], hydroxyl (OH) [16,18,19], fluorine (F) [17,20], and adsorption of NO molecule [21]. It was found that covalently bound impurities, such as hydroxyl groups, can induce midgap states in graphene [16,17].…”

Tuning the electronic properties of reduced bilayer graphene oxide: controllable flat bands and improved conductivity

“…Accordingly, in the current study, the structural and electrical characteristics of several monolayer and bilayer combinations of pure and oxygenated graphene are examined. Although the structure of single-layer oxidized graphene with a pair of epoxy and hydroxyl functional groups has been structurally investigated in earlier studies using ab initio calculations [6], we consider it is also required to present a full investigation and provide specifics. The purpose of this research is to look at the structural geometry and electrical properties of layered graphene-based structures.…”

“…The occurrence of this event around the Fermi level affects the electronic properties of materials. The stretching of the bonds in the direct lattice is typically what causes the development of intermediate gap states in the reciprocal lattice [6]. In 2D structures, the substitution of some atoms and the addition of agents by applying tension to the bands causes a change in the density and energy of electrons, and their ability to mobility in the material, and consequently a change in the energy levels.…”