Atomistic modeling of the thermoelectric power factor in ultra-scaled Silicon nanowires

Dimensional scaling provides an alternative route to improve the thermoelectric figure of merit (ZT) by the reduction of the lattice thermal conductivity(кl). However, this method is reaching the scaling limit. Further improvement in ZT can be achieved by improving the thermoelectric power-factor (S2G), 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.