Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 321-330 |
| Number of pages | 10 |
| Journal | Nano Energy |
| Volume | 35 |
| DOIs | |
| Publication status | Published - May 1 2017 |
Fingerprint
Keywords
- Interstitial defects
- Lattice thermal conductivity
- Off-stoichiometry
- SnSe
- Thermoelectricity
- Transmission electron microscopy
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Electrical and Electronic Engineering
Cite this
Direct observation of vast off-stoichiometric defects in single crystalline SnSe. / Wu, Di; Wu, Lijun; He, Dongsheng; Zhao, Li Dong; Li, Wei; Wu, Minghui; Jin, Min; Xu, Jingtao; Jiang, Jun; Huang, Li; Zhu, Yimei; Kanatzidis, Mercouri G; He, Jiaqing.
In: Nano Energy, Vol. 35, 01.05.2017, p. 321-330.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Direct observation of vast off-stoichiometric defects in single crystalline SnSe
AU - Wu, Di
AU - Wu, Lijun
AU - He, Dongsheng
AU - Zhao, Li Dong
AU - Li, Wei
AU - Wu, Minghui
AU - Jin, Min
AU - Xu, Jingtao
AU - Jiang, Jun
AU - Huang, Li
AU - Zhu, Yimei
AU - Kanatzidis, Mercouri G
AU - He, Jiaqing
PY - 2017/5/1
Y1 - 2017/5/1
N2 - 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.
AB - 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.
KW - Interstitial defects
KW - Lattice thermal conductivity
KW - Off-stoichiometry
KW - SnSe
KW - Thermoelectricity
KW - Transmission electron microscopy
UR - http://www.scopus.com/inward/record.url?scp=85017106227&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85017106227&partnerID=8YFLogxK
U2 - 10.1016/j.nanoen.2017.04.004
DO - 10.1016/j.nanoen.2017.04.004
M3 - Article
VL - 35
SP - 321
EP - 330
JO - Nano Energy
JF - Nano Energy
SN - 2211-2855
ER -