Mechanical and electronic properties of MX/YTe (M = Ge, Sn; X = S, Se, Te) van der Waals heterostructures

Abstract

In this work, we systematically investigated the mechanical and electronic properties of a group of van der Waals heterostructures (vdWHs) stacked by the MX (GeSe, GeTe, SnS and SnSe) and YTe monolayers based on the density functional theory. From the binding energies, the most stable geometry structures were determined: T-type GeSe/YTe, T-type GeTe/YTe, Y-type SnS/YTe and T-type SnSe/YTe. They exhibit excellent mechanical stability with anisotropic Young's moduli ranging from 71.81 N/m to 89.91 N/m. Meanwhile, the T-type GeSe/YTe, GeTe/YTe and SnSe/YTe vdWHs show Ohmic contact, while the Y-type SnS/YTe vdWH shows the n-type Schottky contact with a barrier height of 0.395 eV. Furthermore, we also demonstrated that the transition of Y-type SnS/YTe from n-type Schottky contact to Ohmic contact can be realized by reducing the interlayer distance to 2.672 Å. The work is expected to provide valuable guidance for the fabrication and design of the next generation of low-resistance nanodevices.