Silicene nanoribbons on transition metal dichalcogenide substrates: Effects on electronic structure and ballistic transport
silicene, transition metal dichalcogenides, van der Waals heterostructure, electronic structure, ballistic transport
ABSTRACT The idea of stacking multiple monolayers of different two-dimensional materials has become a global pursuit. In this work, a silicene armchair nanoribbon of width W and van der Waals-bonded to different transition-metal dichalcogenide (TMD) bilayer substrates MoX2 and WX2, where X = S, Se, Te is considered. The orbital resolved electronic structure and ballistic transport properties of these systems are simulated by employing van der Waals-corrected density functional theory and nonequilibrium Green’s functions. We find that the lattice mismatch with the underlying substrate determines the electronic structure, correlated with the silicene buckling distortion and ultimately with the contact resistance of the two-terminal system. The smallest lattice mismatch, obtained with the MoTe2 substrate, results in the silicene ribbon properties coming close to those of a freestanding one. With the TMD bilayer acting as a dielectric layer, the electronic structure is tunable from a direct to an indirect semiconducting layer, and subsequently to a metallic electronic dispersion layer, with a moderate applied perpendicular electric field.
Tsinghua University Press
Bas van den Broek,Michel Houssa,Augustin Lu,Geoffrey Pourtois,Valery Afanas’ev,Andre Stesmans, Silicene nanoribbons on transition metal dichalcogenide substrates: Effects on electronic structure and ballistic transport. NanoRes.2016, 9(11): 3394–3406