{"title":"Low Thermal Conductivity and High Thermoelectric Figure of Merit of Two-Dimensional Ba2ZnAs2 and Ba2ZnSb2","authors":"Chenliang Xia, Xiaofei Sheng, Qin Qun, Wenyu Fang, Bilei Zhou","doi":"10.1002/qua.27465","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>Thermoelectric (TE) technology can effectively alleviate energy shortage and environmental pollution problems and has thus attracted extensive attention. In this work, we designed two unexplored two-dimensional materials, Ba<sub>2</sub>ZnAs<sub>2</sub> and Ba<sub>2</sub>ZnSb<sub>2</sub>, and investigated their stability, mechanical characteristics, and TE properties using first-principles calculations and by solving the Boltzmann transport equation. We revealed that the two materials possess high stability and moderate cleavage energies of 0.84 and 0.76 J m<sup>−2</sup>. Moreover, they are indirect semiconductors with band-gaps of 1.26 and 0.97 eV and show flat energy dispersion near the valence band maximum, resulting in a high p-type Seebeck coefficient of approximately 0.72 and 0.29 mV K<sup>−1</sup> at 300 K. Furthermore, they have significant anisotropic TE power factor along the <i>a</i>- and <i>b</i>-axis, with maxima of 1.19 and 0.75 mW m<sup>−1</sup> K<sup>−2</sup> at 300 K. Owing to the strong coupling between the acoustic and optical phonons, as well as the low frequency for low-lying phonons, the materials have high phonon scattering rates and low lattice thermal conductivities of 0.54/0.52 and 0.81/0.43 W mK<sup>−1</sup> along the <i>a-</i>/<i>b</i>-axis. Ultimately, Ba<sub>2</sub>ZnAs<sub>2</sub> and Ba<sub>2</sub>ZnSb<sub>2</sub> can deliver high-performance TE transport with high figures-of-merit of 0.32 and 0.19 at 300 K, which increase further to 1.67 and 0.91, respectively, at 700 K.</p>\n </div>","PeriodicalId":182,"journal":{"name":"International Journal of Quantum Chemistry","volume":null,"pages":null},"PeriodicalIF":2.3000,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Quantum Chemistry","FirstCategoryId":"92","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/qua.27465","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Thermoelectric (TE) technology can effectively alleviate energy shortage and environmental pollution problems and has thus attracted extensive attention. In this work, we designed two unexplored two-dimensional materials, Ba2ZnAs2 and Ba2ZnSb2, and investigated their stability, mechanical characteristics, and TE properties using first-principles calculations and by solving the Boltzmann transport equation. We revealed that the two materials possess high stability and moderate cleavage energies of 0.84 and 0.76 J m−2. Moreover, they are indirect semiconductors with band-gaps of 1.26 and 0.97 eV and show flat energy dispersion near the valence band maximum, resulting in a high p-type Seebeck coefficient of approximately 0.72 and 0.29 mV K−1 at 300 K. Furthermore, they have significant anisotropic TE power factor along the a- and b-axis, with maxima of 1.19 and 0.75 mW m−1 K−2 at 300 K. Owing to the strong coupling between the acoustic and optical phonons, as well as the low frequency for low-lying phonons, the materials have high phonon scattering rates and low lattice thermal conductivities of 0.54/0.52 and 0.81/0.43 W mK−1 along the a-/b-axis. Ultimately, Ba2ZnAs2 and Ba2ZnSb2 can deliver high-performance TE transport with high figures-of-merit of 0.32 and 0.19 at 300 K, which increase further to 1.67 and 0.91, respectively, at 700 K.
期刊介绍:
Since its first formulation quantum chemistry has provided the conceptual and terminological framework necessary to understand atoms, molecules and the condensed matter. Over the past decades synergistic advances in the methodological developments, software and hardware have transformed quantum chemistry in a truly interdisciplinary science that has expanded beyond its traditional core of molecular sciences to fields as diverse as chemistry and catalysis, biophysics, nanotechnology and material science.