Density Functional Theory Study of the Silicene-like SiX and XSi3 (X = B, C, N, Al, P) Honeycomb Lattices: The Various Buckled Structures and Versatile Electronic Properties

Abstract

Using the density functional theory calculations, we systematically investigate the structures and properties of silicene-like SiX and XSi3 (X = B, C, N, Al, P) hexagonal heterosheets. For the SiX systems, the SiP sheet favors a chairlike buckled structure akin to silicene, the SiB, SiN, and SiAl ones prefer the washboard-like buckling type, and the SiC sheet adopts the flat plane as graphene. The planarity is also favored in the XSi3 sheets with X = B, C, Al, while the rests with X = N and P prefer the chairlike buckled structures. The energetic stabilities and mechanical properties are also investigated for these SiX and XSi3 systems, and all the heterosheets are found to be stable. Unlike the semimetallic silicene, most of the SiX sheets are transformed to metals except for the SiC one with a wide band gap. For the XSi3 systems, they can be metals, semimetals, or narrow-band gap semiconductors depending on the X elements. The BSi3 and NSi3 sheets exhibit metallic behaviors, which behave like the p-type...