Atomistic Modeling of the Thermoelectric Power Factor in Ultra-scaled Silicon Nanowires

摘要

Dimensional scaling provides an alternative route to improve the thermoelectric figure of merit (ZT) by the reduction of the lattice thermal conductivity(K_1). However, this method is reaching the scaling limit. Further improvement in ZT can be achieved by improving the thermoelectric power-factor (S G), the numerator of ZT. In this work we study this part of ZT using a combination of semi-empirical Tight-Binding method and Landauer approach. We study the effect of cross-sectional confinement, wire orientation and uniaxial strain on the power-factor (PF). It is found that any improvement in PF is only achieved for wires with cross-section size less than 6nm × 6nm.