Layer-stacking effect on electronic structures of bilayer arsenene

Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University Lanzhou 730000, China and Key Laboratory of Special Function Materials and Structure Design of Ministry of Education, Lanzhou University - Lanzhou 730000, China

^(a) sims@lzu.edu.cn
^(b) gaocunx@lzu.edu.cn

Received: 6 January 2017
Accepted: 15 February 2017

Abstract

A monolayer of orthorhombic arsenic (arsenene) is a promising candidate for nano-electronic devices due to the uniquely electronic properties. To further extend its practical applications, an additional layer is introduced to tune the electronic structures. Four layer-stacking manners, namely AA-, AB-, AB′-, and AC-stacking, are constructed and studied through using first-principles calculations. Compared with monolayer, an indirect-direct gap transition is realized in AB-stacking. More importantly, a semimetal feature appears in the AC- and AB′-stacked bilayers, leaving the electronic structure of AA-stacking trivial. In addition, the energy dispersion around Γ is largely tuned from the layer-stacking effect. To understand the underlying physics, the approximation is taken to address this issue. Our results show that the level repulsion from the additional layer domaintes the anisotropy of energy dispersion around Γ. The works like ours would shed new light on the tunability of the electronic structure in layered arsenene.