Issue 9, 2023

Engineering an atomic-level crystal lattice and electronic band structure for an extraordinarily high average thermoelectric figure of merit in n-type PbSe

Abstract

We stabilize multiscale defect structures involving interstitial Cu, displaced Pb and Se atoms from the regular lattice points, dislocations prompted by scarce anion vacancies, and nanoscale mosaics driven thermodynamically by the new composition CuxPb(Se0.8Te0.2)0.95 (x = 0–0.0057). Directly observing their atomic-resolution structures, employing a spherical aberration-corrected scanning transmission electron microscope and atom probe tomography, uncovers formation mechanisms, helping understand how they affect bulk transport properties. They independently manipulate the physical quantities determining the thermoelectric figure of merit, ZT. Carrier concentration dynamically boosts electrical conductivity with rising temperature while negligibly damaging carrier mobility. The significantly increased effective mass of electrons in the conduction band above the theoretical prediction gives a high magnitude of Seebeck coefficients. Consequently, the best composition achieves a remarkably high average power factor of ∼24 μW cm−1 K−2 from 300 to 823 K, with a substantially depressed lattice thermal conductivity of ∼0.2 W m−1 K−1 at 723 K. With a ZT of ∼0.55 at 300 K, an average ZT is ∼1.30 from 400 to 823 K, the highest for all n-type polycrystalline thermoelectric systems including PbTe-based materials. The achievement in this work greatly escalates the predictability in designing defect structures for high thermoelectric performance, and demonstrates that PbSe can eventually outperform PbTe in thermoelectrics.

Graphical abstract: Engineering an atomic-level crystal lattice and electronic band structure for an extraordinarily high average thermoelectric figure of merit in n-type PbSe

Supplementary files

Article information

Article type
Paper
Submitted
18 Apr 2023
Accepted
21 Jul 2023
First published
01 Aug 2023

Energy Environ. Sci., 2023,16, 3994-4008

Engineering an atomic-level crystal lattice and electronic band structure for an extraordinarily high average thermoelectric figure of merit in n-type PbSe

B. Ge, H. Lee, J. Im, Y. Choi, S. Kim, J. Y. Lee, S. Cho, Y. Sung, K. Choi, C. Zhou, Z. Shi and I. Chung, Energy Environ. Sci., 2023, 16, 3994 DOI: 10.1039/D3EE01226C

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.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements