Enhanced thermoelectric performance via the solid solution formation: The case of pseudobinary alloy (Cu2Te)(Ga2Te3)(3) upon Sb substitution for Cu
Enhanced thermoelectric performance via the solid solution formation: The case of pseudobinary alloy (Cu2Te)(Ga2Te3)(3) upon Sb substitution for Cu
复制标题
通过固溶体形成增强热电性能：以 Sb 取代 Cu 的准二元合金 (Cu2Te)(Ga2Te3)(3) 为例
DOI：
10.1016/j.matdes.2016.11.024
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发表时间：
2017
影响因子：
8.4
通讯作者：
Chao Yimin
中科院分区：
文献类型：
--
作者：
Cui Jiaolin;Liu Xianglian;Du Zhengliang;Chao Yimin
在本工作中，我们观察了Sb替代铜后固溶体形成对(Cu2(1)−x)Sb2xTe)(Ga2Te3)3热电性能的有利影响。这种替代允许Sb在晶格中的不同位置，即x≤=0.05的Cu位上的Sb和x≥=0.05的Ga位上的Sb，这导致了在假设的有效质量m*下，Pisarenko关系不能准确地捕捉到测量的塞贝克系数。在室温到723K温度范围内，量化了晶格热导率的降低(κL)。在整个组成范围内，在723K和580K温度下，κL值分别降低了33%和25%。这与固溶体中基于Callaway模型的理论计算符合得很好。随着迁移率和电导率的增加，材料的热电性能得到改善，在723K达到最高的ZT值为0.58，约为本征(Cu2Te)(Ga2Te3)3的两倍。
In this work we have observed the beneficial effect from the solid solution formation on the thermoelectric performance of (Cu2(1 −x)Sb2xTe)(Ga2Te3)3upon Sb substitution for Cu. This substitution allows the different occupations of Sb in the crystal lattice, i.e. Sb at Cu sites withx≤ 0.05 and at Ga sides withx≥ 0.05, which has resulted in the Pisarenko relation does not exactly capture the measured Seebeck coefficient under assumed effective massesm*. The reduction of the lattice thermal conductivity (κL) has been quantified within the temperature range from room temperature to 723 K. Over the entire composition range, theκLvalue is reduced by 33% and 25% at temperature 723 K and 580 K, respectively. This observation is in a good agreement with the theoretical calculation based on the Callaway model used in the solid solutions. Along with the increasing of the mobility and electrical conductivity, the thermoelectric performance has been improved with the highestZTvalue of 0.58 at 723 K, which is about double the value of intrinsic (Cu2Te)(Ga2Te3)3.