CRYSTENGCOMM
·
2019
·Vol. 22
·期 2
·248-256
·
IF 3.382
Xiuxia Wang,Chengyan Liu,Junliang Chen,Lei Miao,Shaohai Wu,Xiaoyang Wang,Zhengchuan Xie,Wenjing Xu,Qiufeng Chen
Recently, Ag8SnSe6-based materials, belonging to the family of argyrodite compounds, have been considered as promising thermoelectric candidates due to their intrinsically ultralow lattice thermal conductivity. However, their thermoelectric properties have been rarely investigated because of the intrinsic low carrier concentration. In this work, polycrystalline Ag8SnSe6 bulk materials were successfully synthesized by a bottom-up method by using hydrothermally synthesized Ag8SnSe6 nanocrystals as the precursors. The carrier concentration and mobility of Ag8SnSe6 are successfully enhanced by introducing additional Sn, which should manipulate the self-defects and improve the crystallinity. Thanks to the synergistic optimization of crystal and composition engineering, a maximum ZT value of about 1.22 is achieved for Ag8Sn1.005Se6 at 715 K, which is about 11% higher than that of the pristine sample, and the average ZT is also improved from about 0.65 to about 0.87. This study indicates that crystal engineering and composition engineering play an important role in the thermoelectric properties of Ag8SnSe6 and may provide guidance to improve the thermoelectric performance of other argyrodite compounds.
研究领域:
材料科学
·
热电材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of Advanced Ceramics
·
2022
·Vol. 11
·期 7
·1144-1152
·
IF 11.534
Yu Zhonghai,Wang Xiuxia,Liu Chengyan,Cheng Yiran,Zhang Zhongwei,Si Ruifan,Bai Xiaobo,Hu Xiaokai,Gao Jie,Peng Ying,Miao Lei
The argyrodite compounds (A
m/m+ (12− n )
B n + X
2− 6
(A m + = Li + , Cu + , and Ag+; B n + = Ga 3+ , Si 4+ , Ge 4+ , Sn 4+ , P 5+ , and As 5+ ; and X 2− = S 2− , Se 2− , or Te 2− )) have attracted great attention as excellent thermoelectric (TE) materials due to their extremely low lattice thermal conductivity Among them, Ag 8 SnSe 6 -based TE materials have high potential for TE applications. However, the pristine Ag 8 SnSe 6 materials have low carrier concentration (< 10 17 cm −3 ), resulting in low power factors. In this study, a hydrothermal method was used to synthesize Ag 8 SnSe 6 with high purity, and the introduction of SnBr 2 into the pristine Ag 8 SnSe 6 powders has been used to simultaneously increase the power factor and decrease the thermal conductivity ( κ ). On the one hand, a portion of the Br − ions acted as electrons to increase the carrier concentration, increasing the power factor to a value of ∼698 µW·m −1 ·K −2 at 736 K. On the other hand, some of the dislocations and nanoprecipitates (SnBr 2 ) were generated, resulting in a decrease of κ 1 (−0.13 W·m −1 ·K −1 ) at 578 K. As a result, the zT value reaches ∼1.42 at 735 K for the sample Ag 8 Sn 1.03 Se 5.94 Br 0.06 , nearly 30% enhancement in contrast with that of the pristine sample (−1.09). The strategy of synergistic manipulation of carrier concentration and microstructure by introducing halogen compounds could be applied to the argyrodite compounds to improve the TE properties.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Science Advances
·
2026
·Vol. 12
·期 15
·
IF 13.9
Mengyao Li,Xueke Zhao,Yu Zhang,Jing Yu,Xuyang Liu,Mochen Jia,Hongzhang Song,Dongyang Wang,Jordi Arbiol,Maria Ibáñez,Chongxin Shan,Andreu Cabot,Ziyu Wang
Liquid-like superionic conductors, with highly mobile ions in a rigid framework, offer intrinsically low lattice thermal conductivity without compromising electronic transport. Argyrodite-type Ag 8 SnSe 6 exhibits a melt-like Ag sublattice that drives lattice thermal conductivity (κ L ) below 0.2 watts per meter per kelvin, yet its low carrier concentration limits the power factor. Here, interstitial Ag atoms raise the Fermi level into the conduction band, substantially increasing the electron concentration. Simultaneously, the formation of a secondary Ag 2 Se phase generates lattice distortions that enhance phonon scattering. A pronounced mismatch between electronic (~200 nanometers) and phononic (~0.22 nanometers) mean free paths decouples charge and heat transport, enabling concurrent suppression of κ L and retention of high electrical conductivity. This coupled electronic-phononic modulation yields a record ZT of 0.72 at ambient temperature and a peak ZT of 1.1 at 735 kelvins, with an average ZT avg of 0.72 over 320 to 735 kelvins. A unicouple device achieves 6.3% efficiency under a 357-kelvin gradient, highlighting a practical strategy for high-performance midtemperature thermoelectrics.
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Qixian Zheng,Tingting Zhang,Suiting Ning,Xiangbin Chen,Tian Yu,Zhangheng Lai,Gangjian Tan,Xinfeng Tang,Ning Qi,Zhiquan Chen
As a typical argyrodite compound, Ag8SnSe6 is a very promising candidate for thermoelectric materials due to its inherently ultralow lattice thermal conductivity. However, the main obstacle to further improving its thermoelectric properties is its low intrinsic carrier concentration. Appropriate doping may increase the carrier concentration, but the electronic thermal conductivity will also increase simultaneously, which partially compensates for the optimized power factor. This is particularly prominent for materials with ultralow lattice thermal conductivity. In this study, SnI2 was introduced into Ag8SnSe6, which provides more carriers and thus successfully improves the electrical properties. The maximum power factor at 748 K is enhanced from 4.63 μW cm–1 K–2 to 5.83 μW cm–1 K–2 after adding 3 at. % of SnI2. Meanwhile, the substitution of I for Se weakens the chemical bonding strength, resulting in a lowered sound velocity. In addition, doping of I at the Se site also enhances the bond asymmetry, which causes a stronger lattice anharmonicity. As a result, an extremely low lattice thermal conductivity of 0.058 W m–1 K–1 is achieved at 748 K. Eventually, a high zT value of 1.36 was obtained through the above synergistic optimization, which is a 39% improvement compared to the pristine sample (0.98). Our study demonstrates that chemical bonding engineering is an effective way to further suppress the lattice thermal conductivity of Ag8SnSe6 and also provides guidance for improving the thermoelectric properties of other argyrodite compounds.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）