Enhancing the thermoelectric performance of Cu3SnS4-based solid solutions through coordination of the Seebeck coefficient and carrier concentration. Issue 35 (25th August 2017)

• Record Type: Journal Article
• Authors: Yang, Yuanbo; Ying, Pengzhan; Wang, Jinzhi; Liu, Xianglian; Du, Zhengliang; Chao, Yimin; Cui, Jiaolin
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 35(2017)
• Page Start: 18808
• Page End: 18815
• Publication Date: 2017-08-25
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7ta05253g
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Through coordination of the Seebeck coefficient and carrier concentration in Cu3 SnS4, TE performance improves significantly with the ZT value of 0.75 at 790 K. Abstract : Improving the thermoelectric (TE) performance of Cu3 SnS4 is challenging because it exhibits a metallic behavior, therefore, a strategy should be envisaged to coordinate the carrier concentration ( n H ) and Seebeck coefficient ( α ). The coordination in this work has been realized through the Fermi level ( E f ) unpinning and shifting towards the conduction band (CB) via addition of excess Sn in Cu3 SnS4 . As a result, the solid solution Cu3 Sn1+ x S4 ( x = 0.2) has a moderate α (178.0 μV K −1 ) at 790 K and a high n H (1.54 × 10 21 cm −3 ) value. Along with the lowest lattice thermal conductivity κ L (0.39 W K −1 m −1 ) caused by the increased phonon scattering by carriers, the highest ZT value of 0.75 is attained at ∼790 K. This value is 2.8 times that of the stoichiometric Cu3 SnS4, and stands among the highest for ternary Cu–Sn–S sulfide thermoelectrics at the corresponding temperatures. More importantly, this approach used in the case of ternary Cu3 SnS4 provides a guidance or reference to improve the TE performance of other materials.