Control of Thermoelectric Properties through the addition of Ag in the Bi0.5Sb1.5Te3Alloy
Control of Thermoelectric Properties through the addition of Ag in the Bi0.5Sb1.5Te3Alloy
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DOI：
10.3365/eml.2010.12.201
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发表时间：
2010-12-01
影响因子：
2.4
通讯作者：
Kim, M. H.
中科院分区：
文献类型：
--
作者：
Lee, J. K.;Park, S. D.;Kim, M. H.
本文研究了Al掺杂Bi_（0.5）Sb_（1.5）Te_3化合物在323 ~ 573 K温度范围内的热电性能。通过常规的熔化工艺制造锭，然后使用热压方法烧结从锭中压碎的粉末。Ag掺杂的Bi_（0.5）Sb_（1.5）Te_3化合物的Seebeck系数和电导率随温度的变化具有简并半导体的特征，这与传统的Bi_（0.5）Sb_（1.5）Te_3化合物有很大的不同。四元化合物的功率因数（α（2）σ）大于三元化合物的功率因数，这主要是由于Ag掺杂含量增加了电导率。在323 ~ 523 K温度范围内，其热导率高于无Ag的Bi（0.5）Sb（1.5）Te（3）化合物。晶格热导率在整个温度范围内表现出较低的值。0.05wt. % Ag掺杂化合物和三元合金在373 K和323 K时的热稳定性分别为1.2和0.88。随着Ag掺杂量的增加，每个最大峰ZT向更高的温度区域移动。这可能是由于具有纳米有序层的孪晶结构对晶格热导率的控制。
In this study, the thermoelectric properties of the Ae-doped Bi0.5Sb1.5Te3 compounds were investigated in the temperature ranee from 323 K to 573 K. Ingots were fabricated by a conventional melting process and the powder crushed from ingots was then sintered using a hot-pressing method. The temperature dependence of the Seebeck coefficient and the electrical conductivity of the Ag-doped Bi0.5Sb1.5Te3 compound are characteristic of degenerate semiconductors, which is fairly different from the conventional Bi0.5Sb1.5Te3 compound. The power factor (alpha(2)sigma) of the quaternary compound was larger than that of the ternary, which is mainly due to the increase in the electrical conductivity with doping content of Ag. The thermal conductivity was greater than that of the Ag-freeBi(0.5)Sb(1.5)Te(3)compound in the temperature range from 323 K to 523 K. The lattice thermal conductivity showed low values throughout the temperature range. The maximum value of the dimensionless figure of merit (ZT) of the 0.05 wt. % Ag-doped compound and the ternary alloy were 1.2 at 373 K and 0.88 at 323 K, respectively. Each of the maximum peak ZT shifts to a higher temperature region with increases in the doping content of Ag. This is likely due to the control of the lattice thermal conductivity by the twin structure, which had a nano-ordered layer.