Realizing high power factor and thermoelectric performance in band engineered AgSbTe2

Zhang, Yu, Xing, Congcong, Wang, Dongyang, Genc, Aziz, Lee, Seng Huat, Chang, Cheng, Li, Zhi, Zheng, Luyao, Lim, Khak Ho, Zhu, Hangtian, Smriti, Rabeya Bosry, Liu, Yu, Cheng, Shaobo, Hong, Min, Fan, Xiaolei, Mao, Zhiqiang, Zhao, Li-Dong, Cabot, Andreu, Zhu, Tiejun and Poudel, Bed 2025. Realizing high power factor and thermoelectric performance in band engineered AgSbTe2. Nature Communications 16 (1) , 22. 10.1038/s41467-024-55280-0

Preview

PDF - Published Version Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (3MB) | Preview

Abstract

AgSbTe2 is a promising p-type thermoelectric material operating in the mid-temperature regime. To further enhance its thermoelectric performance, previous research has mainly focused on reducing lattice thermal conductivity by forming ordered nanoscale domains for instance. However, the relatively low power factor is the main limitation affecting the power density of AgSbTe2-based thermoelectric devices. In this work, we demonstrate that hole-doped AgSbTe2 with Sn induces the formation of a new impurity band just above the valence band maximum. This approach significantly improves the electrical transport properties, contrary to previous strategies that focused on reducing lattice thermal conductivity. As a result, we achieve a record-high power factor of 27 μWcm−1K−2 and a peak thermoelectric figure of merit zT of 2.5 at 673 K. This exceptional performance is attributed to an increased hole concentration resulting from the formation of the impurity band and a lower formation energy of the defect complexes (  +  ). Besides, the doped materials exhibit a significantly improved Seebeck coefficient by inhibiting bipolar conductivity and preventing the formation of n-type Ag2Te. Additionally, the optimized AgSbTe2 is used to fabricate a unicouple thermoelectric device that achieves energy conversion efficiencies of up to 12.1% and a high power density of 1.13 Wcm−2. This study provides critical insights and guidance for optimizing the performance of p-type AgSbTe2 in thermoelectric applications.

Item Type:	Article
Date Type:	Published Online
Status:	Published
Schools:	Chemistry Cardiff Catalysis Institute (CCI)
Publisher:	Nature Research
ISSN:	2041-1723
Date of First Compliant Deposit:	3 January 2025
Date of Acceptance:	6 December 2024
Last Modified:	08 Jan 2025 15:16
URI:	https://orca.cardiff.ac.uk/id/eprint/174952

Actions (repository staff only)

Edit Item