High-Temperature Structural and Thermoelectric Study of Argyrodite Ag8GeSe6

doi:10.1021/acsami.8b19819

	High-Temperature Structural and Thermoelectric Study of Argyrodite Ag8GeSe6
	Shen, Xingchen 1,3,4,5; Yang, Chun-Chuen 6; Liu, Yamei 4; Wang, Guiwen 2; Tan, Huan 3; Tung, Yung-Hsiang 6; Wang, Guoyu 1,5; Lu, Xu 3; He, Jian 4; Zhou, Xiaoyuan 2,3
刊名	ACS Applied Materials and Interfaces
	2019
卷号	11 期号:2 页码:2168-2176
ISSN号	19448244
DOI	10.1021/acsami.8b19819
英文摘要	Argyrodites with a general chemical formula of A8BX6 (A = Cu, Ag; B = Si, Ge, Sn; and X = S, Se, and Te) are known for the intimate interplay among mobile ions, electrons, and phonons, which yields rich material physics and materials chemistry phenomena. In particular, the coexistence of fast ionic conduction and promising thermoelectric performance in Ag8GeTe6, Ag8SnSe6, Ag8SiTe6, Ag8SiSe6, and Cu8GeSe6 at high temperatures ushered us to their chemical neighbor Ag8GeSe6, whose high-temperature crystal structure and thermoelectric properties are not yet reported. In this work, we have employed a growth-from-the-melt technique followed by hot pressing to prepare polycrystalline Ag8GeSe6 samples, on which the crystal structure, micro-morphology, compositional analysis, UV-vis absorption, specific heat, speed of sound, and thermoelectric properties were characterized as a function of the Se-deficiency ratio and temperature. We found that (i) the crystal structure of Ag8GeSe6 evolved from orthorhombic at room temperature to face center cubic above 410 K, with a region of phase separations in between; (ii) like other argyrodite 816 phases, Ag8GeSe6 exhibited ultralow thermal conductivities over a wide temperature range as the phonon mean free path was down to the order of interatomic spacing; and (iii) varying Se deficiency effectively optimized the carrier concentration and power factor, a figure of merit zT value ∼0.55 was achieved at 923 K in Ag8GeSe5.88. These results not only fill a knowledge gap of Ag8GeSe6 but also contribute to a comprehensive understanding of 816 phase argyrodites at large. © 2018 American Chemical Society.
电子版国际标准刊号	19448252
语种	英语
内容类型	期刊论文
源URL	[http://119.78.100.138/handle/2HOD01W0/9830]
专题	中国科学院重庆绿色智能技术研究院
作者单位	1.University of Chinese Academy of Sciences, Beijing; 100044, China; 2.Analytical and Testing Center, Chongqing University, Chongqing; 401331, China 3.Chongqing Key Laboratory of Soft Condensed Matter Physics and Smart Materials, College of Physics, Chongqing University, Chongqing; 401331, China; 4.Department of Physics and Astronomy, Clemson University, Clemson; SC; 29634, United States; 5.Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Science, Chongqing; 400714, China; 6.Department of Physics, Chun Yuan Christian University, Chung-Li District, Taoyuan City; 32023, Taiwan;
推荐引用方式 GB/T 7714	Shen, Xingchen,Yang, Chun-Chuen,Liu, Yamei,et al. High-Temperature Structural and Thermoelectric Study of Argyrodite Ag8GeSe6[J]. ACS Applied Materials and Interfaces,2019,11(2):2168-2176.
APA	Shen, Xingchen.,Yang, Chun-Chuen.,Liu, Yamei.,Wang, Guiwen.,Tan, Huan.,...&Zhou, Xiaoyuan.(2019).High-Temperature Structural and Thermoelectric Study of Argyrodite Ag8GeSe6.ACS Applied Materials and Interfaces,11(2),2168-2176.
MLA	Shen, Xingchen,et al."High-Temperature Structural and Thermoelectric Study of Argyrodite Ag8GeSe6".ACS Applied Materials and Interfaces 11.2(2019):2168-2176.