Enhanced Thermoelectric Properties of Variants of Tl9SbTe6 and Tl9BiTe6
Enhanced Thermoelectric Properties of Variants of Tl9SbTe6 and Tl9BiTe6
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DOI：
10.1021/cm402593f
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发表时间：
2013-10
影响因子：
8.6
通讯作者：
Quansheng Guo;M. Chan;Bryan A. Kuropatwa;H. Kleinke
中科院分区：
文献类型：
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作者：
Quansheng Guo;M. Chan;Bryan A. Kuropatwa;H. Kleinke
Tl9BiTe6 是 Tl5Te3 的替代变体，是领先的中温热电材料之一，通过区域熔化制备时，预计在 450 K 以上超过 ZT = 1，热压后在 560 K 时达到 ZT = 0.86。我们根据化学计量比的元素制备了同构系列Tl9Sb1–xTe6、Tl9–xSb1+xTe6、Tl9Bi1–xTe6和Tl9–xBi1+xTe6，其中x的范围为0到0.05，并测定了它们热压后的热电性能。理论上，根据 (Tl+)9(Sb/Bi)3+(Te2–)6，当 x = 0 时，这些碲化物是窄带隙半导体，所有元素都处于共同氧化态。然而，所制备的这种 9-1-6 化学计量的样品表现出相对较高的电导率，该电导率随着温度的升高而降低，表明外在电荷载流子的存在。塞贝克系数通常高于+100 μV K–1。降低 Sb 和 Bi 含量会增加空穴载流子浓度，从而增加电导率，同时...
Tl9BiTe6, a substitution variant of Tl5Te3, is one of the leading midtemperature thermoelectrics and is postulated to exceed ZT = 1 above 450 K when prepared by zone-melting and reach ZT = 0.86 at 560 K after hot-pressing. We have prepared the isostructural series Tl9Sb1–xTe6, Tl9–xSb1+xTe6, Tl9Bi1–xTe6, and Tl9–xBi1+xTe6, with x ranging from 0 to 0.05, from the elements in the stoichiometric ratios and determined their thermoelectric properties after hot-pressing. In theory, these tellurides are narrow-gap semiconductors when x = 0, with all elements in common oxidation states, according to (Tl+)9(Sb/Bi)3+(Te2–)6. The as-prepared samples of this 9-1-6 stoichiometry, however, exhibit relatively high electrical conductivity, which decreases with increasing temperature, indicative of the presence of extrinsic charge carriers. The Seebeck coefficient is generally above +100 μV K–1. Decreasing the Sb and Bi content increases the hole carrier concentration and thus increases the electrical conductivity while d...