Issue 35, 2022

Ultralow thermal conductivity and anisotropic thermoelectric performance in layered materials LaMOCh (M = Cu, Ag; Ch = S, Se)

Abstract

In layered materials with the stacking axis perpendicular to the basal plane, anharmonicity strongly affects phonon propagation due to weak interlayer coupling, which is helpful to reduce the lattice thermal conductivity and improve the thermoelectric (TE) performance significantly. By combining first-principles calculations and the Boltzmann transport equation, we systematically analyzed and evaluated the lattice thermal conductivity and TE properties of LaMOCh (M = Cu, Ag; Ch = S, Se). The results indicate that these layered materials exhibit ultralow lattice thermal conductivities of 0.24–0.37 W m−1 K−1 along the interlayer direction at room temperature. The low lattice thermal conductivities have been analyzed from some inherent phonon properties, such as low acoustic phonon group velocity, large Grüneisen parameters, and a short phonon relaxation time. Originating from their natural layered crystal structure, the thermal and electronic transports (i.e., thermal conductivity, Seebeck coefficient, and electrical conductivity) are both highly anisotropic between their intralayer and interlayer directions. Finally, we obtained ZT values of 1.17 and 1.26 at 900 K along the interlayer direction for n-type LaCuOSe and LaAgOSe, respectively. Generally, LaMOSe exhibit larger anisotropy than LaMOS, in both n- and p-types of doping. Our findings of low thermal conductivities and large anisotropic TE performances of these layered systems should stimulate much attention in BiCuOSe and alike layered TE families.

Graphical abstract: Ultralow thermal conductivity and anisotropic thermoelectric performance in layered materials LaMOCh (M = Cu, Ag; Ch = S, Se)

Supplementary files

Article information

Article type
Paper
Submitted
06 May 2022
Accepted
13 Aug 2022
First published
15 Aug 2022

Phys. Chem. Chem. Phys., 2022,24, 21261-21269

Ultralow thermal conductivity and anisotropic thermoelectric performance in layered materials LaMOCh (M = Cu, Ag; Ch = S, Se)

J. Ma, Q. Liu, P. Liu, P. Zhang, B. Sanyal, T. Ouyang and B. Wang, Phys. Chem. Chem. Phys., 2022, 24, 21261 DOI: 10.1039/D2CP02067J

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