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

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.

The biaxial strain induced properties of ReX2 and ReXS (X = S, Se, Te) monolayers

“…The structure of ReX 2 and ReXS DFT calculations [18,19]. We analyzed the monolayer ReX 2 and ReXS structures, each structure contains 12 atoms, figure 1 shows, the lattice parameter of ReS 2 is a=6.66 Å, b=6.79 Å, c=20 Å. ReSe 2 is irregular hexagon from the main view, from the side, the ReSe 2 is a 'sandwich' shape [20]. The top and bottom layers are Se atoms, and the middle layer is Re atoms.…”

Structural deformation and mechanical response of CrS2, CrSe2 and Janus CrSSe

“…This is analogous to stretching a dough. This analysis shows that a significant geometrical transformation is created due to the applied strain as prescribed in ReXY (X=Y or X≠Y) where X=(S, Se) [42].…”