Enhanced thermoelectric properties of coaxial Bi2Te3/Sb2Te3 nanostructures studied by theoretical modeling

TL;DR

This paper models the thermoelectric properties of coaxial Bi2Te3/Sb2Te3 nanostructures using a Landauer approach, revealing significant ZT enhancement and analyzing how structure influences performance.

Contribution

It introduces a novel modeling scheme based on Landauer approach for thermoelectric properties of nanostructures, differing from traditional BTE methods.

Findings

Significant ZT enhancement observed in modeled nanostructures

Thermoelectric performance depends on structural parameters

Efficiency at maximum power was analyzed for the 1-D system

Abstract

Critical thermoelectric parameters including Seebeck coefficient, electrical conductivity, thermal conductivity and figure of merit ZT of one-dimensional coaxial Bi2Te3/Sb2Te3 nanocomposite were modeled by following the single carrier pocket and sharp interface assumptions. A calculation scheme based on Landauer approach, instead of commonly used Boltzmann transport equation (BTE) with relaxation time approximation, was adopted to numerically obtain the transmission functions which can be used to evaluate thermoelectric properties. Considerable enhancement of ZT was obtained through our modeling and numerical calculation, and the corresponding dependence of thermoelectric performance on structure parameters was studied. Finally, the efficiency at the maximum power condition for this 1-D system was also investigated.