Theoretical analysis of thermoelectric performance in p-type CoSb3 based skutterudite by simultaneous partially void filling and Sn substitution
Theoretical analysis of thermoelectric performance in p-type CoSb3 based skutterudite by simultaneous partially void filling and Sn substitution
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DOI：
10.1016/j.jpcs.2020.109545
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发表时间：
2020-10
影响因子：
4
通讯作者：
Z. Benhalima;M. Sahnoun
中科院分区：
文献类型：
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作者：
Z. Benhalima;M. Sahnoun
cosb3型滑石的研究是一个重要的研究领域。填充它们的结构空隙和/或在取代时在金属或pnicogen位点掺杂它们，改善了点缺陷散射机制，提高了热电优值（ZT），从而提高了塞贝克系数和电导率，降低了导热系数。本文分析了Sn取代对掺杂和部分填充的CoSb3（Ba0.5Co8Sb24-xSnx）结构、电子和热电性能的影响，其中（x = 0,1,2,3和4）。我们的计算是在使用半经典玻尔兹曼输运理论的完全势线性化增广平面波方法（FP-LAPW）中进行的。理论分析表明，ba0.5 co8sb24 - xsnx的电荷平衡强烈依赖于取代构型。Ba0.5Co8Sb23Sn的组成在能量方面是最稳定的。当我们考察Sn取代对电子和热电性能的影响时，我们发现电子性能适中，热电性能得到改善。也就是说，在T = 500K时，Ba0.5Co8Sb23Sn的估计无量纲电子优值（ZTe）约为0.67；将这种材料列为热电应用的有前途的候选材料。
The investigation of CoSb3-based skutterudites is an important research area. Filling their structural voids and/or doping them upon substitution either at the metal or at the pnicogen sites improves the point defect scattering mechanism and enhance the thermoelectric figure of merit (ZT), thus resulting in a higher Seebeck coefficient and electrical conductivity and a lower thermal conductivity. In this work we analyze the effect of Sn substitution on the structural, electronic and thermoelectric properties of doped and partially filled CoSb3(Ba0.5Co8Sb24-xSnx), where (x = 0, 1, 2, 3 and 4). Our calculations are performed within the fully potential-linearized augmented plane wave method (FP-LAPW) using a semi-classical Boltzmann transport theory. The theoretical analysis show that the charge balance of Ba0.5Co8Sb24-xSnxstrongly depends on the substitution configuration. The Ba0.5Co8Sb23Sn composition is the most stable in terms of energy. When we examine the effect of Sn substitution on the electronic and thermoelectric properties, we find that the electronic properties are moderate and thermoelectric performance is improved. That is, the estimated dimensionless electronic figure of merit (ZTe) is approximately 0.67 at T = 500K for Ba0.5Co8Sb23Sn; ranking this material as a promising candidate for thermoelectric applications.