Rb(Zn,Cu)4As3 as a New High-Efficiency Thermoelectric Material

Keigo Ono; Kunihiro Kihou; Hidetomo Usui; Kazuhiko Kuroki; Yosuke Goto; Chul-Ho Lee

doi:10.1021/acsomega.3c06021

Rb(Zn,Cu)₄As₃ as a New High-Efficiency Thermoelectric Material

ACS Omega. 2023 Oct 30;8(45):42900-42906. doi: 10.1021/acsomega.3c06021. eCollection 2023 Nov 14.

Authors

Keigo Ono^{1

2}, Kunihiro Kihou¹, Hidetomo Usui³, Kazuhiko Kuroki⁴, Yosuke Goto¹, Chul-Ho Lee¹

Affiliations

¹ National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan.
² Department of Applied Physics and Physico-Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa 223-8522, Japan.
³ Department of Physics and Materials Science, Shimane University, Matsue, Shimane 690-8504, Japan.
⁴ Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan.

Abstract

The thermoelectric performance of RbZn_4-xCu_xAs₃ crystallized in the KCu₄S₃-type structure was investigated. Samples were synthesized via solid-state reactions, followed by hot pressing. Hole carriers were doped by substituting Zn with Cu until x = 0.02, resulting in an increase of the power factor from 0.049 to 0.52 mW/mK² at T = 797 K. The lattice thermal conductivity was substantially low, with a value of 1.61 W/mK at T = 312 K, independent of doping. This can be attributed to the large vibration of the Rb atoms, as demonstrated by the neutron diffraction analysis. The maximum dimensionless figure of merit, ZT, was 0.53 at T = 797 K, representing the highest value for the 143-Zintl compounds. The result indicated that the 143-Zintl compounds could be a new class of high-performance thermoelectric materials.