Structural, mechanical and electronic properties of two-dimensional structure of III-arsenide (1 1 1) binary compounds: An ab-initio study

Abstract

Structural, mechanical and electronic properties of two-dimensional single-layer hexagonal structures in the (1 1 1) crystal plane of IIIAs-ZnS systems (III = B, Ga and In) are studied by first-principles calculations based on density functional theory (DFT). Elastic and phonon dispersion relation display that 2D h-IIIAs systems (III = B, Ga and In) are both mechanical and dynamically stable. Electronic structures analysis show that the semiconducting nature of the 3D-IIIAs compounds is retained by their 2D single layer counterpart. Furthermore, density of states reveals the influence of σ and π bonding in the most stable geometry (planar or buckled) for 2D h-IIIAs systems. Calculations of elastic constants show that the Young's modulus, bulk modulus and shear modulus decrease for 2D h-IIIAs binary compounds as we move down on the group of elements of the periodic table. In addition, as the bond length between the neighboring cation-anion atoms increases, the 2D h-IIIAs binary compounds display less stiffness and more plasticity. Our findings can be used to understand the contribution of the σ and π bonding in the most stable geometry (planar o buckled) for 2D h-IIIAs systems. Structural and electronic properties of h-IIIAs systems as a function of the number of layers have been also studied. It is shown that h-BAs keeps its planar geometry while both h-GAs and h-InAs retained their buckled ones obtained by their single layers. Bilayer h-IIIAs present the same bandgap nature of their counterpart in 3D. As the number of layers increase from 2 to 4, the bandgap width for layered h-IIIAs decreases until they become semimetal or metal. Interestingly, these results are different to those found for layered h-GaN. The results presented in this study for single and few-layer h-IIIAs structures could give some physical insights for further theoretical and experimental studies of 2D h-IIIV-like systems.

Tunable 2D-gallium arsenide and graphene bandgaps in a graphene/GaAs heterostructure: anab initiostudy

“…We can see the semiconductor Γ-Γ direct nature for 331-GaAs layer, with a bandgap size of 0.72 eV, and a near semimetallic nature of 5.0 meV at K point for 551-graphene layer. This electronic behavior for 331-GaAs (Γ-Γ direct) is different from that one reported for 2D-GaAs monolayer (Γ-K indirect) [24,25].…”

“…ii) Recently, 2D h-GaAs has been reported as a mechanical and dynamically stable semiconductor by first-principles studies [24,25].…”

“…The valence electron configurations for C, Ga and As are considered as 2s 2 2p 2 , 3d 10 4s 2 4p 1 and 3d 10 4s 2 4p 3 , respectively. The hexagonal primitive cell, with one Ga atom and one As atom, see Figure 1(b), was constructed from the zinc-blende structure in the (111) plane [24]. In order to reduce the missmatch between graphene and 2D-GaAs hexagonal monolayers in Graphene/2D-GaAs bilayer heterostructure, a 551/331 supercell geometry has been used in this study, as shown in Figures 1(a), 1(b) and 1(c), respectively.…”

“…The Poisson's ratio represents the plasticity of the material, the 2D layer modulus gives physical insight about the resilience of a material to stretching, and the shear and in-plane Young's moduli indicate the 2D structure stiffness. Gonzalez et al [24] reported for 2D h-IIIAs binary compounds that as moved down on the group of elements of the periodic table, the bond length between the neighboring cation-anion atoms increases and the materials display less stiffness and more plasticity.…”

“…The unique physical properties of twodimensional graphene related materials (2D-GRM), such as low dimensionality, flexibility, high mechanical strength, lightness, in-plane covalent bonding and dangling-bond-free lattice, allow them a variety of potential applications, for instance: catalysis, biomedicine, conductive ink, sensors, coating, light emitting devices, composites, storage and production of energy, touch panels and high frequency electronics, among others [1][2][3][4][5][6][7][8]. Therefore, during the last ten years, the scientific community has developed an intense research on 2D nanomaterials, e.g., graphene [9], X-enes (X = B, Si, Ge, Sn, P, Bi) [10][11][12][13][14][15][16][17][18], X-anes (Graphane, Silicane, Germanane, Stanane) [19,20], fluro-X-enes [20], MXenes [21], IIIV systems [22][23][24][25][26][27], transition metal dichalcogenides (TMDs) [28][29][30][31], layered oxides [32], layered double hydroxides (LDHs) [33], metal-organic frameworks (MOFs) [34,35], covalent organic frameworks (COFs) [36], polymers [37][38][39] and metals [40]…”