Diameter dependent thermoelectric properties of individual SnTe nanowires.
Diameter dependent thermoelectric properties of individual SnTe nanowires.
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DOI：
10.1039/c4nr05870d
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发表时间：
2015-02
期刊：
影响因子：
6.7
通讯作者：
Enzhi Xu;Zhen Li;Zhen Li;J. Martínez;N. Sinitsyn;H. Htoon;Nana Li;B. Swartzentruber;J. Hollingsworth;Jian Wang;Shixiong Zhang
中科院分区：
文献类型：
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作者：
Enzhi Xu;Zhen Li;Zhen Li;J. Martínez;N. Sinitsyn;H. Htoon;Nana Li;B. Swartzentruber;J. Hollingsworth;Jian Wang;Shixiong Zhang
无铅化合物碲化锡（SnTe）是一种很有前途的热电材料。在这项工作中，我们报告的第一个热电研究的个别单晶SnTe纳米线具有不同的直径范围从1218到12913 nm。在25-300 K的温度范围内对相同的纳米线进行了热电势S、电导率σ和热导率κ的测量。虽然电导率没有表现出很强的直径依赖性，热电势增加了两个因素时，纳米线的直径从0.913纳米到0.218纳米减少。所测纳米线的热导率低于体SnTe的热导率，这可能是由于增强的声子-表面边界散射和声子-缺陷散射。针对单个纳米线确定了与温度相关的品质因数ZT，并且在室温下获得的最大值比具有可比载流子密度的大块样品高出约三倍。
The lead-free compound tin telluride (SnTe) has recently been suggested to be a promising thermoelectric material. In this work, we report on the first thermoelectric study of individual single-crystalline SnTe nanowires with different diameters ranging from ∼218 to ∼913 nm. Measurements of thermopower S, electrical conductivity σ and thermal conductivity κ were carried out on the same nanowires over a temperature range of 25-300 K. While the electrical conductivity does not show a strong diameter dependence, the thermopower increases by a factor of two when the nanowire diameter is decreased from ∼913 nm to ∼218 nm. The thermal conductivity of the measured NWs is lower than that of the bulk SnTe, which may arise from the enhanced phonon - surface boundary scattering and phonon-defect scattering. Temperature dependent figure of merit ZT was determined for individual nanowires and the achieved maximum value at room temperature is about three times higher than that in bulk samples of comparable carrier density.