Large thermoelectric power factor at low temperatures in one-dimensional telluride Ta4SiTe4
Large thermoelectric power factor at low temperatures in one-dimensional telluride Ta4SiTe4
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DOI：
10.1063/1.4982623
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发表时间：
2017-05-01
影响因子：
4
通讯作者：
Takenaka, Koshi
中科院分区：
文献类型：
--
作者：
Inohara, Takumi;Okamoto, Yoshihiko;Takenaka, Koshi
我们报告在一维碲化物Ta4SiTe4晶须晶体中发现了超过-400 mu V K-1的非常大的热电势，同时保持了rho = 2m Omega cm的低电阻率，在130 K的最佳温度下产生了P = 80 lW cm(-1) K-2的非常大的功率因数。该温度广泛控制在从50K的低温到室温的范围内 通过化学掺杂，在220~280 K时获得最大P为170 mu W cm(-1) K-2。这些P值远远超过室温附近Bi2Te3-Sb2Te3合金的P值，为实现实用级低温热电制冷提供了途径。一维电子结构和狄拉克半金属附近出现的非常小的带隙的共存可能导致 Ta4SiTe4 中非常大的功率因数，这表明“一维狄拉克半金属”是寻找用于低温应用的高性能热电材料的有前途的方法。由 AIP Publishing 出版。
We report the discovery of a very large thermoelectric power over -400 mu V K-1 in the whisker crystals of a one-dimensional telluride Ta4SiTe4, while maintaining a low electrical resistivity of rho = 2m Omega cm, yielding a very large power factor of P = 80 lW cm(-1) K-2 at an optimum temperature of 130 K. This temperature is widely controlled from the cryogenic temperature of 50K to room temperature by chemical doping, resulting in the largest P of 170 mu W cm(-1) K-2 at 220-280 K. These P values far exceed those of the Bi2Te3-Sb2Te3 alloys at around room temperature, offering an avenue for realizing the practical-level thermoelectric cooling at low temperatures. The coexistence of a one-dimensional electronic structure and a very small band gap appearing in the vicinity of the Dirac semimetals probably causes the very large power factors in Ta4SiTe4, indicating that the "one-dimensional Dirac semimetal" is a promising way to find high-performance thermoelectric materials for the low temperature applications.Published by AIP Publishing.