Improved Thermoelectric Performance for β‑Zn4Sb3 by Na/Zn Co‑doping
Improved Thermoelectric Performance for β‑Zn4Sb3 by Na/Zn Co‑doping
复制标题
通过 Na/Zn Co 掺杂提高 β-Zn4Sb3 的热电性能
DOI：
10.1007/s11664-021-09383-9
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发表时间：
2022
影响因子：
2.1
通讯作者：
Shukang Deng
中科院分区：
文献类型：
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作者：
Jie Zheng;Jiali Chen;Yu Tang;Kaiyuan;Yujie Xiang;Lanxian Shen;Wen Ge;Peizhi Yang;Shukang Deng
本研究以Zn/Sb/NaCl的化学计量比为（4−x）：3:(7+x) (x= 0,0.1, 0.2, 0.3)，采用Zn-NaCl混合通量法制备β- zn4sb3。x射线衍射结果表明，所有样品均为具有空间群的六方菱形晶体结构。在x= 0.2和x= 0.3的样品中检测到第二相ZnSb。此外，由于Na+离子半径大于Zn2+，所有样品的晶胞体积和晶格参数均有所增加。透射电镜图像和相应的区域电子衍射图表明制备的样品具有完整的晶体结构。所有样品均具有空穴导电性和p型导电性。材料的载流子浓度随Na含量的增加和Zn含量的降低而增加，范围从8.89 × 1019cm−3到17.82 × 1019cm−3。x= 0 ~ 0.2样品的导热系数（κ）随Na含量的增加而降低；然而，当x= 0.3时，由于出现了ZnSb相，样品的κ值更高。热重差热分析表明，在熔点以下不发生失重。最终，标称组成为β- zn3.8 sb3nacl7.2的样品在690 K时的azt值为1.43。
In this study,β-Zn4Sb3was prepared using the Zn-NaCl mixed-flux method based on the stoichiometric ratio of Zn/Sb/NaCl = (4−x):3:(7+x) (x= 0, 0.1, 0.2, 0.3). X-ray diffraction results showed that all samples were hexagonal rhombic crystal structures with the space group. A second phase of ZnSb was detected in the samples withx= 0.2 andx= 0.3. In addition, the crystal-cell volume and lattice parameter of all samples increased for the larger ion radius of Na+than Zn2+. The transmission electron microscopy image and corresponding area electron diffraction pattern demonstrated that the prepared samples had a complete crystal structure. All samples had hole conduction and exhibited p-type conduction behavior. The carrier concentration of the material increased with increased Na content and decreased Zn, ranging from 8.89 × 1019cm−3to 17.82 × 1019cm−3. Moreover, the thermal conductivity (κ) ofx= 0–0.2 samples decreased with increased Na content; however, the sample withx= 0.3 had a higherκowing to the appearance of a ZnSb phase. Thermogravimetric differential thermal analysis showed that no weight loss occurred below the melting point. Eventually, the sample with the nominal composition ofβ-Zn3.8Sb3NaCl7.2achieved aZTvalue of 1.43 at 690 K.