A computational study of thermoelectric conversion in the PbSe$_{x}$Te$_{1-x}$ semiconductor alloys

TL;DR

This study uses density functional theory to analyze the structural, electronic, and thermoelectric properties of PbSe, PbTe, and their alloys, revealing promising thermoelectric performance with a figure of merit of 2.55.

Contribution

It provides a comprehensive theoretical analysis of PbSe$_{x}$Te$_{1-x}$ alloys, highlighting their potential as efficient thermoelectric materials.

Findings

PbSe$_{x}$Te$_{1-x}$ alloys have a direct band gap at the L point.

Calculated figure of merit reaches 2.55, indicating high thermoelectric efficiency.

Structural parameters agree well with previous theoretical data.

Abstract

The present theoretical study focuses on the structural, electronic and thermoelectric properties of PbTe, PbSe and their ternary alloys PbSe$_{x}$Te$_{1-x}$, using the density functional theory (DFT) by the full potential linearised augmented plane wave (FP-LAPW) method implemented in Wien2k code. Structural properties were performed by using the generalized gradient approximation of Perdew Burke and Ernzenhof (GGA-PBE) scheme. The results show that the calculated lattice parameters are in good agreement with theoretical data previously obtained. For electronic properties, we noticed that for all the compounds of PbSe$_{x}$Te$_{1-x}$, we have a direct band gap in L point. For thermoelectric properties, we used BoltzTraP2 code and Gibbs2 code. Our results show that the PbSe$_{x}$Te$_{1-x}$ compounds have reached a value of 2.55 for the figure of merit, which indicates that our material is a good thermoelectric candidate.