In Situ Reaction Induced Core–Shell Structure to Ultralow κlat and High Thermoelectric Performance of SnTe. Issue 11 (16th April 2020)

• Record Type: Journal Article
• Authors: Li, Sihui; Xin, Jiwu; Basit, Abdul; Long, Qiang; Li, Suwei; Jiang, Qinghui; Luo, Yubo; Yang, Junyou
• Is Part Of: Advanced science. Volume 7:Issue 11(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-04-16
• Subjects: β‐Zn4Sb3 -- core–shell structures -- in situ decomposition reaction -- SnTe thermoelectric materials -- tin telluride; Science -- Periodicals; 505
• DOI: 10.1002/advs.201903493
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: Lead‐free chalcogenide SnTe has been demonstrated to be an efficient medium temperature thermoelectric (TE) material. However, high intrinsic Sn vacancies as well as high thermal conductivity devalue its performance. Here, β‐Zn4 Sb3 is incorporated into the SnTe matrix to regulate the thermoelectric performance of SnTe. Sequential in situ reactions take place between the β‐Zn4 Sb3 additive and SnTe matrix, and an interesting "core–shell" microstructure (Sb@ZnTe) is obtained; the composition of SnTe matrix is also tuned and thus Sn vacancies are compensated effectively. Benefitting from the synergistic effect of the in situ reactions, an ultralow κlat ≈0.48 W m −1 K −1 at 873 K is obtained and the carrier concentrations and electrical properties are also improved successfully. Finally, a maximum ZT ≈1.32, which increases by ≈220% over the pristine SnTe, is achieved in the SnTe‐1.5% β‐Zn4 Sb3 sample at 873 K. This work provides a new strategy to regulate the TE performance of SnTe and also offers a new insight to other related thermoelectric materials. Abstract : In situ chemical reactions occur between the β‐Zn4 Sb3 additive and SnTe matrix, and the resultant interesting "core–shell" structure is obtained in this work. The composition, microstructure, and transport properties of SnTe thermoelectric materials are synergistically tuned, so an ultralow lattice thermal conductivity (≈0.48 Wm −1 K −1 at 873 K) and relatively high ZT (≈1.32 at 873 K) are achieved, which present an effective method to enhance the thermoelectric performance of SnTe, and are also of referential values for other thermoelectric materials.