气候变化领域集成服务门户(CCPortal): Engineering ferroelectric instability to achieve ultralow thermal conductivity and high thermoelectric performance in Sn 1-: X Ge x Te

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DOI	10.1039/c8ee03162b
	Engineering ferroelectric instability to achieve ultralow thermal conductivity and high thermoelectric performance in Sn 1-: X Ge x Te
	Banik A.; Ghosh T.; Arora R.; Dutta M.; Pandey J.; Acharya S.; Soni A.; Waghmare U.V.; Biswas K.
发表日期	2019
ISSN	17545692
起始页码	589
结束页码	595
卷号	12 期号:2
英文摘要	High thermoelectric performance of a crystalline solid requires it to have low thermal conductivity which is one of the utmost material challenges. Herein, we demonstrate how the local structural distortions and the associated ferroelectric lattice instability induced soft polar phonons effectively scatter the heat carrying acoustic phonons and help achieve ultralow lattice thermal conductivity in SnTe by engineering the instability near room temperature via Ge (x = 0-30 mol%) alloying. While Sn 1-x Ge x Te possesses a global cubic structure above room temperature (x < 0.5), by analysing synchrotron X-ray pair distribution functions (PDFs) we showed that local rhombohedral distortion exists which is sustained up to the studied maximum temperature (∼600 K) above the ferroelectric transition (T C = 290 K). We showed that the local rhombohedral distortions in global cubic Sn 1-x Ge x Te are predominantly associated with local Ge off-centering which forms a short-range chain-like structure and scatters acoustic phonons, resulting in an ultralow lattice thermal conductivity of ∼0.67 W m -1 K -1 . In addition, Sb doping in Sn 1-x Ge x Te enhances the Seebeck coefficient due to p-type carrier optimization and valence band convergence, which leads to a synergistic boost in the thermoelectric figure of merit, zT, to ∼1.6 at 721 K. The concept of engineering ferroelectric instability to achieve ultralow thermal conductivity is applicable to other crystalline solids, which opens up a general opportunity to enhance the thermoelectric performance. © 2019 The Royal Society of Chemistry.
英文关键词	Coefficient of performance; Crystal lattices; Crystalline materials; Distribution functions; Electromagnetic wave emission; Ferroelectricity; Germanium; IV-VI semiconductors; Phonons; Stability; Thermal conductivity of solids; Thermoelectricity; Tin alloys; Tin compounds; Ferroelectric instability; Ferroelectric transition; Lattice thermal conductivity; Low thermal conductivity; Pair distribution functions; Rhombohedral distortion; Thermoelectric figure of merit; Thermoelectric performance; Thermal Engineering; crystallinity; electrical method; energy efficiency; engineering; heat capacity; instability; iron; optimization; phase transition; temperature profile; thermal conductivity
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/189978
作者单位	New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore, 560064, India; Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore, 560064, India; School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh, 175005, India; School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore, 560064, India
推荐引用方式 GB/T 7714	Banik A.,Ghosh T.,Arora R.,et al. Engineering ferroelectric instability to achieve ultralow thermal conductivity and high thermoelectric performance in Sn 1-: X Ge x Te[J],2019,12(2).
APA	Banik A..,Ghosh T..,Arora R..,Dutta M..,Pandey J..,...&Biswas K..(2019).Engineering ferroelectric instability to achieve ultralow thermal conductivity and high thermoelectric performance in Sn 1-: X Ge x Te.Energy & Environmental Science,12(2).
MLA	Banik A.,et al."Engineering ferroelectric instability to achieve ultralow thermal conductivity and high thermoelectric performance in Sn 1-: X Ge x Te".Energy & Environmental Science 12.2(2019).