Achieving High Thermoelectric Figure of Merit in Polycrystalline SnSe via Introducing Sn Vacancies

IMR OpenIR

	Achieving High Thermoelectric Figure of Merit in Polycrystalline SnSe via Introducing Sn Vacancies
	Wei, W; Chang, C; Yang, T; Liu, JZ; Tang, HC; Zhang, J; Li, YS; Xu, F; Zhang, ZD; Li, JF; Tang, GD; Tang, GD (reprint author), Nanjing Univ Sci & Technol, Sch Mat Sci & Engn, MIIT Key Lab Adv Metall & Intermetall Mat Technol, Nanjing 210094, Jiangsu, Peoples R China.
	2018-01-10
发表期刊	JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
ISSN	0002-7863
卷号	140 期号:1 页码:499-505
摘要	Thermoelectric power generation technology has emerged as a clean "heat engine" that can convert heat to electricity. Recently, the discovery of an ultrahigh thermoelectric figure of merit in SnSe crystals has drawn a great deal of attention. In view of their facile processing and scale-up applications, polycrystalline SnSe materials with ZT values comparable to those of the SnSe crystals are greatly desired. Here we achieve a record high ZT value similar to 2.1 at 873 K in polycrystalline Sn1-xSe with Sn vacancies. We demonstrate that the carrier concentration increases by artificially introducing Sn vacancies, contributing significantly to the enhancements of electrical conductivity and thermoelectric power factor. The detailed analysis of the data in the light of first-principles calculations results indicates that the increased carrier concentration can be attributed to the Sn-vacancy-induced Fermi level downshift and the interplay between the vacancy states and valence bands. Furthermore, vacancies break translation symmetry and thus enhance phonon scattering, leading to extralow thermal conductivity. Such high ZT value similar to 2.1 is achieved by synergistically optimizing both electrical- and thermal-transport properties of polycrystalline SnSe. The vast increase in ZT for polycrystalline SnSe may accelerate practical applications of this material in highly effective solid-state thermoelectric devices.; Thermoelectric power generation technology has emerged as a clean "heat engine" that can convert heat to electricity. Recently, the discovery of an ultrahigh thermoelectric figure of merit in SnSe crystals has drawn a great deal of attention. In view of their facile processing and scale-up applications, polycrystalline SnSe materials with ZT values comparable to those of the SnSe crystals are greatly desired. Here we achieve a record high ZT value similar to 2.1 at 873 K in polycrystalline Sn1-xSe with Sn vacancies. We demonstrate that the carrier concentration increases by artificially introducing Sn vacancies, contributing significantly to the enhancements of electrical conductivity and thermoelectric power factor. The detailed analysis of the data in the light of first-principles calculations results indicates that the increased carrier concentration can be attributed to the Sn-vacancy-induced Fermi level downshift and the interplay between the vacancy states and valence bands. Furthermore, vacancies break translation symmetry and thus enhance phonon scattering, leading to extralow thermal conductivity. Such high ZT value similar to 2.1 is achieved by synergistically optimizing both electrical- and thermal-transport properties of polycrystalline SnSe. The vast increase in ZT for polycrystalline SnSe may accelerate practical applications of this material in highly effective solid-state thermoelectric devices.
部门归属	[wei, wei ; liu, jizi ; li, yusheng ; xu, feng ; tang, guodong] nanjing univ sci & technol, sch mat sci & engn, miit key lab adv metall & intermetall mat technol, nanjing 210094, jiangsu, peoples r china ; [chang, cheng] beihang univ, sch mat sci & engn, beijing 100091, peoples r china ; [yang, teng ; zhang, zhidong] chinese acad sci, shenyang natl lab mat sci, inst met res, 72 wenhua rd, shenyang 110016, liaoning, peoples r china ; [tang, huaichao ; li, jing-feng] tsinghua univ, sch mat sci & engn, state key lab new ceram & fine proc, beijing 100084, peoples r china ; [zhang, jian] chinese acad sci, inst solid state phys, key lab mat phys, hefei 230031, anhui, peoples r china
关键词	Performance Bulk Thermoelectrics Thermal-conductivity Crystals Bicuseo
学科领域	Chemistry, Multidisciplinary
资助者	National Key R&D Program of China [2017YFA0206301]; Major Program of Aerospace Advanced Manufacturing Technology Research Foundation NSFC, China [U1537204]; National Natural Science Foundation of China [U1732153, 51571007, 51601094]; Natural Science Foundation of Jiangsu Province [BK20161495]; Priority Academic Program Development of Jiangsu Higher Education Institutions; Major Program of Aerospace Advanced Manufacturing Technology Research Foundation CASC, China [U1537204]; Fundamental Research Funds for the Central Universities [30917011206]
收录类别	SCI
语种	英语
WOS记录号	WOS:000422813300083
引用统计	被引频次：187[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/79587
专题	中国科学院金属研究所
通讯作者	Tang, GD (reprint author), Nanjing Univ Sci & Technol, Sch Mat Sci & Engn, MIIT Key Lab Adv Metall & Intermetall Mat Technol, Nanjing 210094, Jiangsu, Peoples R China.
推荐引用方式 GB/T 7714	Wei, W,Chang, C,Yang, T,et al. Achieving High Thermoelectric Figure of Merit in Polycrystalline SnSe via Introducing Sn Vacancies[J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,2018,140(1):499-505.
APA	Wei, W.,Chang, C.,Yang, T.,Liu, JZ.,Tang, HC.,...&Tang, GD .(2018).Achieving High Thermoelectric Figure of Merit in Polycrystalline SnSe via Introducing Sn Vacancies.JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,140(1),499-505.
MLA	Wei, W,et al."Achieving High Thermoelectric Figure of Merit in Polycrystalline SnSe via Introducing Sn Vacancies".JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 140.1(2018):499-505.