{"title":"Thermoelectric properties of low thermal conductivity half Heuslers TiXPb (X = Ni, Pd, Pt): A first principles investigation","authors":"","doi":"10.1016/j.commatsci.2024.113250","DOIUrl":null,"url":null,"abstract":"<div><p>Semiconducting half-Heusler alloys are potential candidates for thermoelectric generators operational at high temperatures. In this work, the stability, electronic, and thermoelectric properties of 18 valence electron TiXPb (X<span><math><mo>=</mo></math></span>Ni, Pd, Pt) compounds are investigated using density functional theory and semi-classical Boltzmann transport theory. The compounds are both thermodynamically and dynamically stable. We find them to be semiconductors with indirect band gaps lying between 0.32−0.64 eV. Our calculations show that from thermoelectric performance perspective electrons exhibit better transport properties than holes. A combination of large power factor and low lattice thermal conductivity results in <span><math><mrow><mi>z</mi><mi>T</mi><mo>></mo><mn>1</mn></mrow></math></span> in all the materials. Our calculations predict that amongst the three compounds, TiPtPb have a maximum value of <span><math><mrow><mi>z</mi><mi>T</mi></mrow></math></span> for both electrons and holes. In this material our calculation yields a maximum <span><math><mrow><mi>z</mi><mi>T</mi></mrow></math></span> of 2.22 at 900 K for n-type doping at a doping concentration of 9.46 × <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>20</mn></mrow></msup></mrow></math></span> <span><math><msup><mrow><mi>cm</mi></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></math></span> and 1.80 at 900 K for p-type doping at a doping concentration of 4.51 × <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>20</mn></mrow></msup></mrow></math></span> <span><math><msup><mrow><mi>cm</mi></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></math></span>.</p></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":null,"pages":null},"PeriodicalIF":3.1000,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Computational Materials Science","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0927025624004713","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Semiconducting half-Heusler alloys are potential candidates for thermoelectric generators operational at high temperatures. In this work, the stability, electronic, and thermoelectric properties of 18 valence electron TiXPb (XNi, Pd, Pt) compounds are investigated using density functional theory and semi-classical Boltzmann transport theory. The compounds are both thermodynamically and dynamically stable. We find them to be semiconductors with indirect band gaps lying between 0.32−0.64 eV. Our calculations show that from thermoelectric performance perspective electrons exhibit better transport properties than holes. A combination of large power factor and low lattice thermal conductivity results in in all the materials. Our calculations predict that amongst the three compounds, TiPtPb have a maximum value of for both electrons and holes. In this material our calculation yields a maximum of 2.22 at 900 K for n-type doping at a doping concentration of 9.46 × and 1.80 at 900 K for p-type doping at a doping concentration of 4.51 × .
期刊介绍:
The goal of Computational Materials Science is to report on results that provide new or unique insights into, or significantly expand our understanding of, the properties of materials or phenomena associated with their design, synthesis, processing, characterization, and utilization. To be relevant to the journal, the results should be applied or applicable to specific material systems that are discussed within the submission.