Influence of electron scatterings on thermoelectric effect

Abstract

In this work, we employed non-equilibrium Green's function to investigate the electron transport properties in the nanowire with the presence of scatterings. The scattering mechanism is modelled by using the concept of Büttiker probe. The effect of electron scattering is analyzed under three conditions: absence of external field; with a bias voltage; and with a finite temperature difference.It is found weak and strong scatterings strength affect the electron transport in different ways. In the case of weak scattering strength, electron trapping increase the electron density, hereafter boost the conductance significantly. Although the increment in conductance would reduce the Seebeck coefficient slightly, the power factor still increases. In the case of strong scattering strength, electron diffraction causes the redistribution of electrons, accumulation of electron at the ends of the wire blocks current flow; hence the conductance is reduced significantly. Although the Seebeck coefficient increases slightly, the power factor still decreases. The power factor is enhanced by 6% − 18%, at the optimum scattering strength.

Thermoelectric devices based on one-dimensional nanostructures

“…At the optimum electron scattering, the thermoelectric power factor could be enhanced by 6-18%. 166 Another theoretical study revealed that the external perpendicular electric eld could increase the Seebeck coefficient of the bismuth telluride NWs by a factor of 2 and the enhanced ZT could reach a value as high as 3.4 at room temperature. 162 In order to investigate the effect of electric elds on nanostructures experimentally, the electric eld is usually added to the device as a gate.…”

Investigation on transport properties in nanowires with contacts

“…Secondly (in section 6.2), we investigate the influence of electron scattering on TE effect [24]. The scattering effect is modeled by using the concept of Buttiker probe.…”