Manipulating the Ge Vacancies and Ge Precipitates through Cr Doping for Realizing the High-Performance GeTe Thermoelectric Material

doi:10.1002/smll.201906921

CORC > 宁波材料技术与工程研究所 > 中国科学院宁波材料技术与工程研究所 > 2020专题

	Manipulating the Ge Vacancies and Ge Precipitates through Cr Doping for Realizing the High-Performance GeTe Thermoelectric Material
	Shuai, Jing ; Sun, Yang ; Tan, Xiaojian ; Mori, Takao
刊名	SMALL
	2020
卷号	16 期号:13
关键词	FIGURE-OF-MERIT ULTRALOW THERMAL-CONDUCTIVITY POWER-FACTOR ENHANCEMENT BAND-STRUCTURE CONVERGENCE SUPPRESSION ALLOY PBTE
DOI	10.1002/smll.201906921
英文摘要	GeTe alloy is a promising medium-temperature thermoelectric material but with highly intrinsic hole carrier concentration by thermodynamics, making this system to be intrinsically off-stoichiometric with Ge vacancies and Ge precipitations. Generally, an intentional increase of formation energy of Ge vacancy by element substitution will lead to an effective dissolution of Ge precipitates for reduction in hole concentration. Here, an opposite direction of decreasing the formation energy of Ge vacancies is demonstrated by substituting Cr at Ge site. This strategy produces more but nearly homogenously distributed Ge precipitations and Ge vacancies, which provides enhanced phonon scattering and effectively reduces the lattice thermal conductivity. Furthermore, Cr atom carries one more electron than Ge and serves as an electron donor for decreasing the hole carrier concentrations. Further optimization incorporates the effect of Bi substitution for facilitating band convergence. A maximum figure of merit (ZT) of 2.0 at 600 K with average ZT of over 1.2 is achieved in the sample of Ge0.92Cr0.03Bi0.05Te, making it one of the best thermoelectric materials for medium-temperature application.
学科主题	Chemistry ; Science & Technology - Other Topics ; Materials Science ; Physics
内容类型	期刊论文
源URL	[http://ir.nimte.ac.cn/handle/174433/19948]
专题	2020专题
作者单位	1.Mori, T (corresponding author), Univ Tsukuba, Grad Sch Pure & Appl Sci, Tennoudai 1-1-1, Tsukuba, Ibaraki 3058671, Japan. 2.Mori, T (corresponding author), NIMS, WPI Int Ctr Mat Nanoarchitechton WPI MANA, Namiki 1-1, Tsukuba, Ibaraki 3050044, Japan.
推荐引用方式 GB/T 7714	Shuai, Jing,Sun, Yang,Tan, Xiaojian,et al. Manipulating the Ge Vacancies and Ge Precipitates through Cr Doping for Realizing the High-Performance GeTe Thermoelectric Material[J]. SMALL,2020,16(13).
APA	Shuai, Jing,Sun, Yang,Tan, Xiaojian,&Mori, Takao.(2020).Manipulating the Ge Vacancies and Ge Precipitates through Cr Doping for Realizing the High-Performance GeTe Thermoelectric Material.SMALL,16(13).
MLA	Shuai, Jing,et al."Manipulating the Ge Vacancies and Ge Precipitates through Cr Doping for Realizing the High-Performance GeTe Thermoelectric Material".SMALL 16.13(2020).