Medium Entropy‐Enabled High Performance Cubic GeTe Thermoelectrics

Bibliographic Details
Title: Medium Entropy‐Enabled High Performance Cubic GeTe Thermoelectrics
Authors: Shizhen Zhi, Jibiao Li, Lipeng Hu, Junqin Li, Ning Li, Haijun Wu, Fusheng Liu, Chaohua Zhang, Weiqin Ao, Heping Xie, Xinbing Zhao, Stephen John Pennycook, Tiejun Zhu
Source: Advanced Science, Vol 8, Iss 12, Pp n/a-n/a (2021)
Publisher Information: Wiley, 2021.
Publication Year: 2021
Collection: LCC:Science
Subject Terms: band engineering, entropy engineering, GeTe, phase transition, thermoelectric, Science
More Details: Abstract The configurational entropy is an emerging descriptor in the functional materials genome. In thermoelectric materials, the configurational entropy helps tune the delicate trade‐off between carrier mobility and lattice thermal conductivity, as well as the structural phase transition, if any. Taking GeTe as an example, low‐entropy GeTe generally have high carrier mobility and distinguished zT > 2, but the rhombohedral‐cubic phase transition restricts the applications. In contrast, despite cubic structure and ultralow lattice thermal conductivity, the degraded carrier mobility leads to a low zT in high‐entropy GeTe. Herein, medium‐entropy alloying is implemented to suppress the phase transition and achieve the cubic GeTe with ultralow lattice thermal conductivity yet decent carrier mobility. In addition, co‐alloying of (Mn, Pb, Sb, Cd) facilitates multivalence bands convergence and band flattening, thereby yielding good Seebeck coefficients and compensating for decreased carrier mobility. For the first time, a state‐of‐the‐art zT of 2.1 at 873 K and average zTave of 1.3 between 300 and 873 K are attained in cubic phased Ge0.63Mn0.15Pb0.1Sb0.06Cd0.06Te. Moreover, a record‐high Vickers hardness of 270 is attained. These results not only promote GeTe materials for practical applications, but also present a breakthrough in the burgeoning field of entropy engineering.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2198-3844
Relation: https://doaj.org/toc/2198-3844
DOI: 10.1002/advs.202100220
Access URL: https://doaj.org/article/2a5e22dc302c4f9b918bfedbaf2e45fc
Accession Number: edsdoj.2a5e22dc302c4f9b918bfedbaf2e45fc
Database: Directory of Open Access Journals
More Details
ISSN:21983844
DOI:10.1002/advs.202100220
Published in:Advanced Science
Language:English