Transport properties and thermoelectric effects in gated silicene superlattices

Low-dimensional thermoelectricity opens the possibility of improving the performance and the efficiency of thermoelectric devices by redistributing the electron density of states through the reduction of dimensionality. In this work, we explore this possibility in silicene by reducing its dimensionality through the periodic arrangement of gated electrodes, the so-called gated silicene superlattices. Silicene electrons were described quantum relativistically. The transmission, conductance, and thermoelectric properties were obtained with the transfer matrix method, the Landauer-Buttiker formalism, and the Cutler-Mott formula, respectively. We find that the redistribution of the density of states together with the intrinsic characteristics of silicene, the local bandgap and the large spin-orbit coupling, contribute to the enhancement of the thermoelectric properties. In particular, the Seebeck coefficient and the power factor reach values of a few mV/K and nW/K-2. These findings in conjunction with the low thermal conductivity of silicene indicate that silicene-based nanostructures could be the basis of more efficient thermoelectric devices. Published by AIP Publishing.