Thermoelectric performance of tellurium and sulfur double-substituted skutterudite materials
Thermoelectric performance of tellurium and sulfur double-substituted skutterudite materials
复制标题
碲硫双取代方钴矿材料的热电性能
DOI：
10.1007/s10853-014-8141-3
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发表时间：
2014-07-01
影响因子：
4.5
通讯作者：
Zhang, Qingjie
中科院分区：
文献类型：
--
作者：
Duan, Bo;Zhai, Pengcheng;Zhang, Qingjie
采用固相反应法合成了Co4Sb11.3Te0.7-xS（x）（x = 0.07-0.2）和Co 4Sb 12-xS（x）（x = 0.07-0.15）两个系列的方钴矿材料，并采用放电等离子烧结法进行了烧结。样品的特征在于粉末X射线衍射，电子探针分析，和测量的电导率，霍尔系数，塞贝克系数，和热导率。结果表明，采用本研究方法制备的Co 4Sb 12-xS（x）中的硫最有可能形成CoSbS化合物，不易进入CoSb 3晶格;而采用本研究方法制备的Co 4Sb 12-xTe（x）化合物中，由于半径补偿，硫可以固溶。在800 K时，晶格热导率从单掺碲的Co4Sb11.3Te0.7的2.07 Wm（-1）K-1下降到Co4Sb11.3Te0.7-xS（x）（x = 0.07-0.20）的1.46-1.67 Wm（-1）K-1。碲硫共掺杂显著提高了Co4Sb11.3Te0.7-xS（x）化合物的热电性能，在Co4Sb11.3Te0.63S0.07中获得了接近1.1的峰值无量纲优值。这种增强主要是由于硫缺陷增加了声子散射，从而大大降低了晶格热导率。
Two series of skutterudite materials, Co4Sb11.3Te0.7-x S (x) (x = 0.07-0.2) and Co4Sb12-x S (x) (x = 0.07-0.15), were synthesized through solid state reaction and consolidated by spark plasma sintering. The samples were characterized by powder X-ray diffraction, electron probe analysis, and measurements of electrical conductivity, Hall coefficient, Seebeck coefficient, and thermal conductivity. The results indicate that sulfur in Co4Sb12-x S (x) most likely forms the CoSbS compound and is unlikely to get into the CoSb3 lattice, while it can dissolve in Co4Sb12-x Te (x) compounds due to the radius compensation when fabricated by the methods in this study. The lattice thermal conductivity decreases from 2.07 Wm(-1) K-1 for tellurium single-doped Co4Sb11.3Te0.7 to 1.46-1.67 Wm(-1) K-1 for Co4Sb11.3Te0.7-x S (x) (x = 0.07-0.20) at 800 K. The thermoelectric performance is significantly enhanced by tellurium-sulfur co-doping in Co4Sb11.3Te0.7-x S (x) compounds, and a peak dimensionless figure of merit similar to 1.1 is achieved in Co4Sb11.3Te0.63S0.07. The enhancement is mainly attributed to the great reduction of the lattice thermal conductivity due to the increased phonon scattering by the sulfur defect.