Strain-Mediated Stability of Structures and Electronic Properties of ReS2, Janus ReSSe, and ReSe2 Monolayers

Jia-Qi Zong,Chang-Wen Zhang,Shu-Feng Zhang,Wei-Xiao Ji,Ping Li,Pei-Ji Wang

doi:10.1155/2019/9239487

Abstract

Monolayers of transition metal ReX2 and ReSX (X=S, Se) have been proposed as new electronic materials for nanoscale devices. In this paper, there are three structures: ReS2, Janus ReSSe, and ReSe2. Based on the first-principles theory, we analyzed the structures, electronic properties, and Fermi speed. Remarkably, we studied the stability of structures of ReS2, Janus ReSSe, and ReSe2 monolayers under biaxial tensile and compressive strain by density functional approach. It is worth noting that when the strain changes, not only the band gap changes but also the band gap properties (direct and indirect) also change. The bond gaps decrease with the increase of tensile strain and compressive strain; Moreover, when the strain is greater than 0, the bond angle decreases as the strain increases, and when the strain is less than 0, the bond angle increases as the strain increases.

Highlights

It has been proposed that the transition metal dichalcogenide (TMD) [1] ReX2 is expected to become the generation of new electronic materials due to the inherent electron bandgap
When the compressive strain is greater than 2% and the tensile strain is greater than 6%, the band gap exhibits indirect band gap, in which case the ReS2 monolayer is a kind of indirect band gap semiconductor
The ReS2 single layer shows that the band gap changes are not obvious when the tensile strain and compressive strain are 0~4% and the band gap changes are not obvious when the compressive strain is greater than 4%; the band gap changes are not obvious when the tensile strain is greater than 4%

Summary

Introduction

It has been proposed that the transition metal dichalcogenide (TMD) [1] ReX2 is expected to become the generation of new electronic materials due to the inherent electron bandgap. This led to studies on the physical and chemical properties of such structures, such as ReS2, ReSe2, WS2, WSSe, and WSe2 [2, 3]. Strain regulation on TMD can induce semiconductor-metal transition [14] After such electronic regulation, it can be understood as the band gap change, and carrier mobility will change [15]. The specific situation is analyzed in detail in Result and Discussion

Method

Findings

Result and Discussion

Conclusion