Demonstration of valley anisotropy utilized to enhance the thermoelectric power factor

Li A, Hu C, He B, Yao M, Fu C, Wang Y, Zhao X, Felser C, Zhu T (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Nature Communications Nature Publishing Group: Nature Communications

Book Volume: 12

Article Number: 5408

Journal Issue: 1

DOI: 10.1038/s41467-021-25722-0

Abstract

Valley anisotropy is a favorable electronic structure feature that could be utilized for good thermoelectric performance. Here, taking advantage of the single anisotropic Fermi pocket in p-type Mg3Sb2, a feasible strategy utilizing the valley anisotropy to enhance the thermoelectric power factor is demonstrated by synergistic studies on both single crystals and textured polycrystalline samples. Compared to the heavy-band direction, a higher carrier mobility by a factor of 3 is observed along the light-band direction, while the Seebeck coefficient remains similar. Together with lower lattice thermal conductivity, an increased room-temperature zT by a factor of 3.6 is found. Moreover, the first-principles calculations of 66 isostructural Zintl phase compounds are conducted and 9 of them are screened out displaying a pz-orbital-dominated valence band, similar to Mg3Sb2. In this work, we experimentally demonstrate that valley anisotropy is an effective strategy for the enhancement of thermoelectric performance in materials with anisotropic Fermi pockets.

Involved external institutions

Zhejiang University / Chekiang University / 浙江大学 CN China (CN) Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids DE Germany (DE)

How to cite

APA:

Li, A., Hu, C., He, B., Yao, M., Fu, C., Wang, Y.,... Zhu, T. (2021). Demonstration of valley anisotropy utilized to enhance the thermoelectric power factor. Nature Communications, 12(1). https://doi.org/10.1038/s41467-021-25722-0

MLA:

Li, Airan, et al. "Demonstration of valley anisotropy utilized to enhance the thermoelectric power factor." Nature Communications 12.1 (2021).

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