# Quaternary compounds Ag2XYSe4 (X=Ba, Sr; Y=Sn, Ge) as novel potential thermoelectric materials

## TL;DR

This study uses first-principle calculations to evaluate the thermoelectric properties of novel quaternary compounds Ag2XYSe4, revealing their potential as efficient thermoelectric materials with high ZT values at elevated temperatures.

## Contribution

It systematically explores the electronic, phonon, mechanical, and thermoelectric properties of Ag2XYSe4 compounds, identifying their high thermoelectric efficiency and potential for practical applications.

## Key findings

- Maximum ZT of 1.22 at 900 K for n-type Ag2SrGeSe4
- ZT values up to 1.20 for p-type Ag2SrSnSe4
- Potential of Ag2XYSe4 compounds as promising thermoelectric materials

## Abstract

Experimental results have shown that the quaternary compound Cu2ZnSnSe4 is an excellent thermoelectric material. This inspires us to seek the other quaternary compounds with similar chemical formula to Cu2ZnSnSe4 as thermoelectric materials. In this paper, we use the first-principle method to systematically explore the electronic and phonon structures, mechanical, thermal and thermoelectric properties of p- and n-type Ag2XYSe4 (X=Ba, Sr; Y=Sn, Ge). It is found that the ZT maximum for n-type Ag2SrGeSe4 can reach up to 1.22 at 900 K, and those for p-type Ag2SrSnSe4, Ag2SrGeSe4 and Ag2BaSnSe4 can reach up to 1.20, 1.13 and 1.12, respectively. Our work not only shows that Ag2XYSe4 (X=Ba, Sr; Y=Sn, Ge) are a kind of potential thermoelectric materials, but also can inspire more theoretical and experimental researches on thermoelectric properties of quaternary compounds.

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Source: https://tomesphere.com/paper/1908.02305