Direct observation of vast off-stoichiometric defects in single crystalline SnSe

Wu, Di1; Wu, Lijun2; He, Dongsheng1; Zhao, Li-Dong3; Li, Wei1; Wu, Minghui1; Jin, Min4; Xu, Jingtao4; Jiang, Jun4; Huang, Li1; Zhu, Yimei2; Kanatzidis, Mercouri G.5; He, Jiaqing1

2017-05

10.1016/j.nanoen.2017.04.004

Nano Energy   影响因子和分区

2211-2855

2211-3282

Single crystalline tin selenide (SnSe) recently emerged as a very promising thermoelectric material for waste heat harvesting and thermoelectric cooling, due to its record high figure of merit ZT in mediate temperature range. The most striking feature of SnSe lies in its extremely low lattice thermal conductivity as ascribed to the anisotropic and highly distorted Sn-Se bonds as well as the giant bond anharmonicity by previous studies, yet no theoretical models so far can give a quantitative explanation to such low a lattice thermal conductivity. In this work, we presented direct observation of an astonishingly vast number of off-stoichiometric Sn vacancies and Se interstitials, using sophisticated aberration corrected scanning transmission electron microscope; and credited the previously reported ultralow thermal conductivity of the SnSe single crystalline samples partly to their off-stoichiometric feature. To further validate the conclusion, we also synthesized stoichiometric SnSe single crystalline samples, and illustrated that the lattice thermal conductivity is deed much higher as compared with the off-stoichiometric single crystals. The scattering efficiency of individual point defect on heat-carrying phonons was then discussed in the state-of-art Debye-Callaway model.

Thermoelectricity Transmission electron microscopy Interstitial defects Off-stoichiometry Lattice thermal conductivity SnSe

SCI ; EI

英语

第一 ; 通讯

Department of Energy, Office of Science Basic Energy Sciences[DE-SC0014520]

Chemistry ; Science & Technology - Other Topics ; Materials Science ; Physics

Chemistry, Physical ; Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Physics, Applied

WOS:000400647900035

ELSEVIER SCIENCE BV

20171503556185

Crystal lattices ; Crystalline materials ; High resolution transmission electron microscopy ; Layered semiconductors ; Point defects ; Selenium compounds ; Single crystals ; Thermal conductivity ; Thermoelectricity ; Transmission electron microscopy ; Waste heat

Energy Losses (industrial and residential):525.4 ; Thermodynamics:641.1 ; Electricity: Basic Concepts and Phenomena:701.1 ; Optical Devices and Systems:741.3 ; Crystalline Solids:933.1 ; Crystal Lattice:933.1.1

Web of Science

1.Southern Univ Sci & Technol, Shenzhen Key Lab Thermoelect Mat, Dept Phys, Shenzhen 518055, Peoples R China
2.Brookhaven Natl Lab, Condensed Matter Phys & Mat Sci Dept, Upton, NY 11973 USA
3.Beihang Univ, Sch Mat Sci & Engn, Beijing 100191, Peoples R China
4.Chinese Acad Sci, NIMTE, Ningbo 315201, Zhejiang, Peoples R China
5.Northwestern Univ, Dept Chem, 2145 Sheridan Rd, Evanston, IL 60208 USA

Wu, Di,Wu, Lijun,He, Dongsheng,et al. Direct observation of vast off-stoichiometric defects in single crystalline SnSe[J]. Nano Energy,2017,35:321-330.

Wu, Di.,Wu, Lijun.,He, Dongsheng.,Zhao, Li-Dong.,Li, Wei.,...&He, Jiaqing.(2017).Direct observation of vast off-stoichiometric defects in single crystalline SnSe.Nano Energy,35,321-330.

Wu, Di,et al."Direct observation of vast off-stoichiometric defects in single crystalline SnSe".Nano Energy 35(2017):321-330.