Structural and Electronic Properties of Layered Arsenic and Antimony Arsenide

Abstract

Layered materials exhibit intriguing electronic characteristics and the search for new types of two-dimensional (2D) structures is of importance for future device fabrication. Using state-of-art first principle calculations, we identify and characterize the structural and electronic properties of two 2D layered arsenic materials, namely, arsenic and its alloy AsSb. The stable 2D structural configuration of arsenic is confirmed to be the low-buckled two-dimensional hexagonal structure by phonon and binding energy calculations. The monolayer exhibits indirect semiconducting properties with gap around 1.5 eV (corrected to 2.2 eV by hybrid function), which can be modulated into a direct semiconductor within a small amount of tensile strain. These semiconducting properties are preserved when cutting into 1D nanoribbons, but the band gap is edge dependent. It is interesting to find that an indirect to direct gap transition can be achieved under strain modulation of the armchair ribbon. Essentially the same phenomena can be found in layered AsSb, except a weak Rashba induced band splitting is present in AsSb due to the nonsymmetric structure and spin orbit coupling. When an additional layer is added on the top, a semiconductor−metal transition will occur. The findings here broaden the family of 2D materials beyond graphene and transition metal dichalcogenides and provide useful information for experimental fabrication of new layered materials with possible application in optoelectronics. ■ INTRODUCTIONOwing to their remarkable properties, 1,2 in recent years graphene-like 2D materials have attracted much research attention as emerging materials for nanoelectronics. As exemplified by recently synthesized graphene, 3,4 silicene, 5−7 boron-nitride nanosheets, 8−10 transition-metal dichalcogenides (TMDs), 11 and black phosphorus, 12,13 these materials are theoretically predicted and experimentally confirmed to possess novel properties which are different from or even better than those of their bulk counterparts. These 2D layered materials can exhibit versatile electronic properties, including metallic, semiconducting, superconducting, and even topological insulator 14 properties with extremely high mobility. With many promising applications in nanoelectronics and optoelectronics such as field-effect transistors (FETs), optoelectronics devices, photovoltaic solar cells, valley electronics, and spintronics applications, 11,15,16 they are considered to represent a relatively new and exciting area for nanotechnology. In this context, both the fundamental scientific importance and the promise of practical applications makes the exploration of new layered materials with novel properties a vigorous field of research in condensed matter physics and materials research.The 2D layered materials with single elemental constitution that have currently been synthesized/fabricated are mainly located in the right part of periodic table, namely, groups IV and V. For example, the commonly studied graphene, 3 silicene, germanium, 17 and tin fi...

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

“…They also showed that these structures are stable against the long-wavelength displacements indicating the stability at T = 0 K. The predicted semiconducting character having a band gap in the range of 1.5-2.10 eV and other properties of arsenene have attracted considerable interest. Very recently, various theoretical studies contributed for better understanding of arsenene [10][11][12][13][14][15][16]. Promising progress towards the synthesis of these phases has also been reported [17].…”

Optical properties of single-layer and bilayer arsenene phases

“…Diverse allotropes of arsenene have been studied more with a focus on their structural, mechanical, and electronic properties, where arsenene and antimonene were also found to display high carrier mobility, superior mechanical properties, negative Poisson's ratio, and possible topological phase transition features in themselves [19][20][21][22][23][24][25][26][27]. The layered three-dimensional (3D) phase of arsenic, i.e., gray arsenic, presents strong evidence that single-layer arsenic can exist as a local minima in the Born-Oppenheimer surface.…”

Electronic Structure and Carrier Mobility of Two-Dimensional α Arsenic Phosphide

“…[11][12][13] The indirect band gap of its monolayer can also be tuned to a direct band gap under biaxial strain. 14 Herein, we investigate interesting electronic properties of 2D phases of arsenic phosphide under strain. This material differs from pure phosphorene or arsenene in that it can possess more diverse phases depending on the topological arrangement of the two types of atoms.…”