Highly efficient transverse thermoelectric devices with Re4Si7 crystals

Michael R. Scudder; Bin He; Yaxian Wang; Akash Rai; David G. Cahill; Wolfgang Windl; Joseph P. Heremans; Joshua E. Goldberger

doi:10.1039/D1EE00923K

Highly efficient transverse thermoelectric devices with Re₄Si₇ crystals†

Michael R. Scudder,^a Bin He,^b Yaxian Wang,

^c Akash Rai,^d David G. Cahill,^d Wolfgang Windl,^c Joseph P. Heremans

^bce and Joshua E. Goldberger

*^a

Author affiliations

* Corresponding authors

^a Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
E-mail: goldberger.4@osu.edu

^b Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210, USA

^c Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA

^d Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA

^e Department of Physics, The Ohio State University, Columbus, OH 43210, USA

Abstract

The principal challenges in current thermoelectric power generation modules are the availability of stable, diffusion-resistant, lossless electrical and thermal metal–semiconductor contacts that do not degrade at the hot end nor cause reductions in device efficiency. Transverse thermoelectric devices, in which a thermal gradient in a single material induces a perpendicular voltage, promise to overcome these problems. However, the measured material transverse thermoelectric efficiencies, z_xyT, of nearly all materials to date has been far too low to confirm these advantages in an actual device. Here, we show that single crystals of Re₄Si₇, an air-stable, thermally robust, layered compound, have a transverse z_xyT of 0.7 ± 0.15 at 980 K, a value that is on par with existing commercial longitudinal theremoelectrics today. Through constructing and characterizing a transverse power generation module, we prove that extrinsic losses through contact resistances are minimized in this geometry, and that no electrical contacts are needed at the hot side. This excellent transverse thermoelectric performance arises from the large, oppositely signed in-plane p-type and cross-plane n-type thermopowers. These large anisotropic thermopowers arise from thermal population of the highly anisotropic valence band and isotropic conduction band in this narrow gap semiconductor. Overall, this work establishes Re₄Si₇ as the “gold-standard” of transverse thermoelectrics, allowing future exploration of unique device architectures for waste heat recovery.

Supplementary files

Article information

DOI: https://doi.org/10.1039/D1EE00923K
Article type: Paper
Submitted: 26 Mar 2021
Accepted: 11 May 2021
First published: 11 May 2021

Download Citation

Energy Environ. Sci., 2021,14, 4009-4017

Author version available

Download author version (PDF)

Permissions

Request permissions

Highly efficient transverse thermoelectric devices with Re₄Si₇ crystals

M. R. Scudder, B. He, Y. Wang, A. Rai, D. G. Cahill, W. Windl, J. P. Heremans and J. E. Goldberger, Energy Environ. Sci., 2021, 14, 4009 DOI: 10.1039/D1EE00923K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Energy & Environmental Science