Electron Transport Through Ag-Silicene-Ag Junctions

Abstract

For several years the electronic structure properties of the novel two-dimensional system silicene have been studied extensively. Electron transport across metal-silicence junctions, however, remains relatively unexplored. To address this issue, we developed and implemented a theoretical framework that utilizes the tight-binding Fisher-Lee relation to span non-equilibrium Green's function (NEGF) techniques, the scattering method, and semiclassical Boltzmann transport theory. Within this hybrid quantum-classical, two-scale framework, we calculated transmission and reflection coefficients of monolayer and bilayer Ag-silicene-Ag junctions using the NEGF method in conjunction with density functional theory; derived and calculated the group velocities; and computed resistance using the semi-classical Boltzmann equation. We found that resistances of these junctions are $\sim${}$ 0.08 \fom$ for monolayer silicene junctions and $\sim${}$ 0.3 \fom$ for bilayer ones, factors of $\sim$8 and $\sim$2, respectively, smaller than Sharvin resistances estimated via the Landauer formalism.