High-thermoelectric performance of nanostructured bismuth antimony telluride bulk alloys
High-thermoelectric performance of nanostructured bismuth antimony telluride bulk alloys
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DOI：
10.1126/science.1156446
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发表时间：
2008-05-02
期刊：
影响因子：
56.9
通讯作者：
Ren, Zhifeng
中科院分区：
文献类型：
--
作者：
Poudel, Bed;Hao, Qing;Ren, Zhifeng
50多年来，碲化铋(BiSbTe)块体合金的无量纲热电优值(ZT)一直保持在1左右。我们发现，在p型纳米晶BiSbTe块体合金中，100℃时可以获得1.4的峰值ZT。这些纳米晶块状材料是通过热压纳米粉末在惰性条件下由晶锭球磨而成。电输运测量，结合微观结构研究和模拟表明，ZT的改善是由于晶界和缺陷的声子散射增加而导致导热系数降低的结果。更重要的是，ZT在室温下约为1.2，在25摄氏度时约为0.8，这使得这些材料适用于冷却和发电。使用这些材料的冷却装置产生了86摄氏度、106摄氏度和119摄氏度的高温差，其中热端温度分别设置为50摄氏度、100摄氏度和150摄氏度。这一发现为使用新的纳米复合材料方法开发高性能、低成本的块状热电材料奠定了基础。
The dimensionless thermoelectric figure of merit ( ZT) in bismuth antimony telluride ( BiSbTe) bulk alloys has remained around 1 for more than 50 years. We show that a peak ZT of 1.4 at 100 degrees C can be achieved in a p- type nanocrystalline BiSbTe bulk alloy. These nanocrystalline bulk materials were made by hot pressing nanopowders that were ball- milled from crystalline ingots under inert conditions. Electrical transport measurements, coupled with microstructure studies and modeling, show that the ZT improvement is the result of low thermal conductivity caused by the increased phonon scattering by grain boundaries and defects. More importantly, ZT is about 1.2 at room temperature and 0.8 at 25 degrees C, which makes these materials useful for cooling and power generation. Cooling devices that use these materials have produced high- temperature differences of 86 degrees, 106 degrees, and 119 degrees C with hot- side temperatures set at 50 degrees, 100 degrees, and 150 degrees C, respectively. This discovery sets the stage for use of a new nanocomposite approach in developing high- performance low- cost bulk thermoelectric materials.