Contour plots of the deformation charge density (∆ρ1and ∆ρ2). (a, b) ∆ρ1 on the planes passing through germanene and sulfur layers in the Ger/MoS2 superlattice. (c,d) ∆ρ1 on the planes passing through silicene and sulfur layers in the Sil/MoS2 system. (e,f) ∆ρ1 on the planes perpendicular to the atomic layers and passing through Mo-S, Ge-Ge, or Si-Si bonds in the superlattices. (g,h) Charge density differences (∆ρ2) of the same planes as those in (e) and (f). The green/blue, purple, and yellow balls represent Ge/Si, Mo, and S atoms, respectively. Orange and blue lines correspond to Δρ > 0 and Δρ < 0, respectively.
Li et al. Nanoscale Research Letters 2014 9:110 doi:10.1186/1556-276X-9-110