Thermoelectric Figure-of-Merit of Fully Dense Single-Crystalline SnSe
Type
ArticleAuthors
Wei, Pai-ChunBhattacharya, Sriparna
Liu, Yu Fei
Liu, Fengjiao
He, Jian
Tung, Yung Hsiang
Yang, Chun Chuen
Hsing, Cheng Rong
Nguyen, Duc Long
Wei, Ching Ming
Chou, Mei Yin
Lai, Yen Chung
Hung, Tsu Lien
Guan, Syu You
Chang, Chia Seng
Wu, Hsin Jay
Lee, Chi Hung
Li, Wen Hsien
Hermann, Raphael P.
Chen, Yang Yuan
Rao, Apparao M.
Date
2019-03-19Online Publication Date
2019-03-19Print Publication Date
2019-03-31Permanent link to this record
http://hdl.handle.net/10754/631790
Metadata
Show full item recordAbstract
Single-crystalline SnSe has attracted much attention because of its record high figure-of-merit ZT ≈ 2.6; however, this high ZT has been associated with the low mass density of samples which leaves the intrinsic ZT of fully dense pristine SnSe in question. To this end, we prepared high-quality fully dense SnSe single crystals and performed detailed structural, electrical, and thermal transport measurements over a wide temperature range along the major crystallographic directions. Our single crystals were fully dense and of high purity as confirmed via high statistics 119Sn Mössbauer spectroscopy that revealed <0.35 at. % Sn(IV) in pristine SnSe. The temperature-dependent heat capacity (Cp) provided evidence for the displacive second-order phase transition from Pnma to Cmcm phase at Tc ≈ 800 K and a small but finite Sommerfeld coefficient γ0 which implied the presence of a finite Fermi surface. Interestingly, despite its strongly temperature-dependent band gap inferred from density functional theory calculations, SnSe behaves like a low-carrier-concentration multiband metal below 600 K, above which it exhibits a semiconducting behavior. Notably, our high-quality single-crystalline SnSe exhibits a thermoelectric figure-of-merit ZT ∼1.0, ∼0.8, and ∼0.25 at 850 K along the b, c, and a directions, respectively.Citation
Wei P-C, Bhattacharya S, Liu Y-F, Liu F, He J, et al. (2019) Thermoelectric Figure-of-Merit of Fully Dense Single-Crystalline SnSe. ACS Omega 4: 5442–5450. Available: http://dx.doi.org/10.1021/acsomega.8b03323.Sponsors
The authors wish to acknowledge Prof. Terry Tritt (Clemson University) for providing access to low temperature measurement facilities in his laboratory, and Prof. Julian Goldsmid, Dr. Pooja Puneet, and Prakash Parajuli for valuable discussions. We also thank National Institute of Standards and Technology and Dr. Jeffrey W. Lynn for providing the neutron beam time that made the neutron rocking curve measurements possible. R.P.H. thanks Dipanshu Bansal and Jiawang Hong for numerical phonon data in refs (11) and (26).Publisher
American Chemical Society (ACS)Journal
ACS OmegaAdditional Links
https://pubs.acs.org/doi/10.1021/acsomega.8b03323ae974a485f413a2113503eed53cd6c53
10.1021/acsomega.8b03323