A strategy for boosting the thermoelectric performance of famatinite Cu3SbS4

Taiki Tanishita; Koichiro Suekuni; Hirotaka Nishiate; Chul-Ho Lee; Michitaka Ohtaki

doi:10.1039/c9cp06233e

A strategy for boosting the thermoelectric performance of famatinite Cu₃SbS₄

Phys Chem Chem Phys. 2020 Jan 28;22(4):2081-2086. doi: 10.1039/c9cp06233e. Epub 2020 Jan 6.

Authors

Taiki Tanishita¹, Koichiro Suekuni², Hirotaka Nishiate³, Chul-Ho Lee³, Michitaka Ohtaki²

Affiliations

¹ Department of Applied Science for Electronics and Materials, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816-8580, Japan. suekuni.koichiro.063@m.kyushu-u.ac.jp.
² Department of Applied Science for Electronics and Materials, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816-8580, Japan. suekuni.koichiro.063@m.kyushu-u.ac.jp and Transdisciplinary Research and Education Center for Green Technologies, Kyushu University, Kasuga, Fukuoka 816-8580, Japan.
³ Research Institute for Energy Conservation, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan.

PMID: 31904070
DOI: 10.1039/c9cp06233e

Abstract

Famatinite Cu₃SbS₄ has attracted attention for its potential application in thermoelectric (TE) contexts. In this work, we report the impacts of co-substituting Ge and P for Sb on TE properties. Melting and heat treatment methods were adopted to synthesize samples of Cu₃Sb_1-x-yGe_xP_yS₄ (x≤ 0.4, y≤ 0.3). In this system, Ge functioned as an acceptor for doping a hole to the valence band, which led to enhancement of the TE power factor. Contrastingly, P barely altered the electronic structure. Furthermore, both Ge and P acted as point defects, which effectively decreased lattice thermal conductivity. The combined effects of the co-substitution gave rise to an enhanced dimensionless figure of merit, ZT, of 0.67 at 673 K.