Stability of single-layer and multilayer arsenene and their mechanical and electronic properties

Abstract

Using first-principles spin-polarized density functional theory, we carried out an analysis on the atomic structure, stability, energetics, and mechanical and electronic properties of single-layer structures of arsenene. These are buckled honeycomb, symmetric, and asymmetric washboard arsenene structures. Our analysis is extended to include layered three-dimensional crystalline phase of arsenic, as well as bilayer and trilayer structures to reveal dimensionality effects. The buckled honeycomb and symmetric washboard structures are shown to maintain their stability at high temperatures even when they are freestanding. As a manifestation of the confinement effect, the large fundamental band gap of single-layer phases decreases with increasing number of layers and eventually is closed. Concomitantly, lattice constants partially increase, while interlayer distances decrease. The effects of hybrid functional or self-energy corrections together with the spin-orbit coupling on the electronic structure of arsenene are crucial. The responses of direct and indirect band gaps to biaxial or uniaxial strain are rather complex and directional; while the fundamental band gap decreases and changes from indirect to direct with the biaxial strain applied to buckled arsenene, these effects are strongly directional for washboard arsenene. The width and the indirect/direct character of the band gap can be tuned by the number of layers, as well as by applied uniaxial/biaxial strain.

Theoretical studies on tunable electronic structures and potential applications of two‐dimensional arsenene‐based materials

“…With n further increasing to infinity, the stacking of puckered layers turned to form the orthorhombic arsenic crystal in accompany with the bandgap variation in the range of 1.4–0.4 eV. The spin‐polarized DFT calculations were also performed to study monolayer, bilayer, and trilayer structures of arsenene with an aim to unveil the nanoscale size effects . Important effects from the selection of hybrid functional, self‐interaction corrections, and SOC were demonstrated (Figure ).…”

“…(c) and (d) Band structures of b ‐As and w ‐As bilayers obtained by Perdew‐Burke‐Eruzerhof–spin‐orbit coupling (PBE‐SOC) and Heyd‐Scuseria‐Ernzerhof (HSE‐SOC) functionals. (Reprinted with permission from Reference . Copyright 2016 American Physical Society)…”

“…The variation of physical properties induced by changing the number of layers is prominent in bilayered and multilayered arsenene nanomaterials. [87][88][89][90][91] With the number of arsenene layers (n) increasing from one to two, few-layered arsenenes were demonstrated to undergo a transition from indirect-gap to direct-gap semiconductors. 89 The energy shift of the band gap induced by the quantum-confinement effect was found to change with the variation of thickness.…”

“…The spin-polarized DFT calculations were also performed to study monolayer, bilayer, and trilayer structures of arsenene with an aim to unveil the nanoscale size effects. 87 Important effects from the selection of hybrid The structures of armchair and zigzag As nanoribbons. The Na (Nz) denotes the number of the repeated units across the nanoribbon width functional, self-interaction corrections, and SOC were demonstrated (Figure 7).…”

“…Prospects for potential applications of monolayer arsenene were also explored through the studies of responses to external strain, electric field, magnetic field, and light stimuli. Strain exerted on arsenene nanomaterials is able to change geometric structures and affect the electronic orbital hybridization, charge distribution, and bond strength, 20,21,87,88,[125][126][127] paving the way for achieving novel electronic properties of the monolayer arsenene. When applying an electromagnetic field, arsenene monolayer may bear low light emission efficiency due to its indirect bandgap feature.…”