Predicted High Thermoelectric Performance of Quasi-Two-Dimensional Compound GeAs Using First-Principles Calculations

The electronic structure of binary quasi-two-dimensional GeAs is investigated using first-principles calculations,and it is found that the anisotropic structure of the layered compound GeAs brings about the anisotropy of the transport properties. Meanwhile, the band structure of GeAs exhibits a rela...

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Bibliographic Details
Published in:中国物理快报：英文版 2017 (11), p.84-87
Main Author: 邹代峰 余传斌 李宇豪 欧云
Format: Article
Language:English
Online Access:Get full text
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Summary:The electronic structure of binary quasi-two-dimensional GeAs is investigated using first-principles calculations,and it is found that the anisotropic structure of the layered compound GeAs brings about the anisotropy of the transport properties. Meanwhile, the band structure of GeAs exhibits a relatively large dispersion near the valence-band maximum in the Z-V direction while it is rather flat in the Z-(?) direction, which is highly desirable for good thermoelectric performance. The calculated partial charge density distribution also reveals that GeAs possesses anisotropic electrical conductivity. Based on the semi-classical Boltzmann transport theory,the anisotropic transport properties are observed, and the optimal doping concentrations are estimated. The temperature dependence transport properties of p-type GeAs are compared with the experimental data in good agreement, and the theoretical figure-of-merit ZT has been predicted as well.
ISSN:0256-307X
1741-3540