Abir Bouchrit, Kamal Assiouan, Hanan Ziani, El khamkhami Jamal, Abdelfettah Achahbar
{"title":"Optimizing thermoelectric properties of CoTiP half-Heusler via doping with Br-, Se- and Ge atoms using first principle study","authors":"Abir Bouchrit, Kamal Assiouan, Hanan Ziani, El khamkhami Jamal, Abdelfettah Achahbar","doi":"10.1016/j.jpcs.2024.112449","DOIUrl":null,"url":null,"abstract":"<div><div>The optimization of thermoelectric materials is crucial for advancing energy conversion technologies. This study explores the electrical and thermoelectric properties of Br-, Ge-, and Se-doped CoTiP half-Heusler compounds using the plane-augmented-wave (PAW) method based on Density Functional Theory (DFT) alongside the semiclassical Boltzmann transport equation (BTE) and Debye-Callaway approximation. While previous research has focused on various doping strategies to enhance thermoelectric performance, specific impacts of Br, Ge, and Se doping on the electronic structure of CoTiP remain unexplored. Our analysis reveals that Ge-doped CoTiP exhibits the largest band gap energy of 1.2597 eV, followed by Se- and Br-doped structures with band gaps of 0.8064 eV and 0.678 eV, respectively. The Fermi level shifts towards the conduction band for both Br- and Se-doped alloys while shifting towards the valence band for Ge-doped alloys. Upon doping, we observe significant enhancements in the Seebeck coefficient and electrical conductivity. Power factor (S<sup>2</sup>σ) enhancements range from 0.01611 W/m K<sup>2</sup> for CoTiP<sub>0.875</sub>Br<sub>0.125</sub>, 0.03445 W/m K<sup>2</sup> for CoTiP<sub>0.875</sub>Se<sub>0.125</sub> and finally, 0.04191 W/m K<sup>2</sup> for CoTiP<sub>0.875</sub>Ge<sub>0.125</sub>, surpassing undoped material values by up to 93 %. Finally, the optimal value of figure of merit (ZT) increases to 0.65, 0.57, and 0.2 at 900 K, achieved by doping Ge, Se and Br, respectively, at the P site, with performance gain about 92 %. Hence, doping has optimized the thermoelectric performance of the CoTiP half-Heusler.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"198 ","pages":"Article 112449"},"PeriodicalIF":4.3000,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Physics and Chemistry of Solids","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022369724005845","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The optimization of thermoelectric materials is crucial for advancing energy conversion technologies. This study explores the electrical and thermoelectric properties of Br-, Ge-, and Se-doped CoTiP half-Heusler compounds using the plane-augmented-wave (PAW) method based on Density Functional Theory (DFT) alongside the semiclassical Boltzmann transport equation (BTE) and Debye-Callaway approximation. While previous research has focused on various doping strategies to enhance thermoelectric performance, specific impacts of Br, Ge, and Se doping on the electronic structure of CoTiP remain unexplored. Our analysis reveals that Ge-doped CoTiP exhibits the largest band gap energy of 1.2597 eV, followed by Se- and Br-doped structures with band gaps of 0.8064 eV and 0.678 eV, respectively. The Fermi level shifts towards the conduction band for both Br- and Se-doped alloys while shifting towards the valence band for Ge-doped alloys. Upon doping, we observe significant enhancements in the Seebeck coefficient and electrical conductivity. Power factor (S2σ) enhancements range from 0.01611 W/m K2 for CoTiP0.875Br0.125, 0.03445 W/m K2 for CoTiP0.875Se0.125 and finally, 0.04191 W/m K2 for CoTiP0.875Ge0.125, surpassing undoped material values by up to 93 %. Finally, the optimal value of figure of merit (ZT) increases to 0.65, 0.57, and 0.2 at 900 K, achieved by doping Ge, Se and Br, respectively, at the P site, with performance gain about 92 %. Hence, doping has optimized the thermoelectric performance of the CoTiP half-Heusler.
期刊介绍:
The Journal of Physics and Chemistry of Solids is a well-established international medium for publication of archival research in condensed matter and materials sciences. Areas of interest broadly include experimental and theoretical research on electronic, magnetic, spectroscopic and structural properties as well as the statistical mechanics and thermodynamics of materials. The focus is on gaining physical and chemical insight into the properties and potential applications of condensed matter systems.
Within the broad scope of the journal, beyond regular contributions, the editors have identified submissions in the following areas of physics and chemistry of solids to be of special current interest to the journal:
Low-dimensional systems
Exotic states of quantum electron matter including topological phases
Energy conversion and storage
Interfaces, nanoparticles and catalysts.