The electronic transport properties of zigzag phosphorene-like MX (M = Ge/Sn, X = S/Se) nanostructures

Single-layer phosphorene-like MX sheets have aroused new interest and could become a family of nanomaterials in physics and materials science. Using a first-principles method combined with non-equilibrium Green's function (NEGF) theory, we study the electronic transport properties of the zigzag phosphorene-like MX (M = Ge/Sn, X = S/Se) nanostructures. The results demonstrate that GeS and GeSe nanoribbons display very similar electronic transport properties. Their current–voltage (I–V) curves exhibit an interesting negative differential resistive (NDR) effect and are insensitive to their ribbon widths due to their similar band structures. However, for SnS and SnSe nanoribbons, their electronic transport properties are obviously dependent on their ribbon widths due to their different band structures. Most of the SnS nanoribbons display the current-limited effect. SnSe nanoribbons could also present a NDR effect, which appeared at a lower applied bias. The currents mainly propagate through the phosphorene-like MX nanoribbons along the metal-termination, while little along the S/Se-termination. Moreover, their two-dimensional monolayers present an obvious difference from their one-dimensional structures. These phosphorene-like MX nanostructures have potential applications in nanoelectronics, and could become candidates for nanodevices, such as NDR devices.