Realizing high figure of merit in heavy-band p-type half-Heusler thermoelectric materials.
Realizing high figure of merit in heavy-band p-type half-Heusler thermoelectric materials.
复制标题
实现重带p型半霍斯勒热电材料的高品质因数
DOI：
10.1038/ncomms9144
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发表时间：
2015-09-02
影响因子：
16.6
通讯作者：
Zhu T
中科院分区：
文献类型：
--
作者：
Fu C;Bai S;Liu Y;Tang Y;Chen L;Zhao X;Zhu T
固态热电技术为将废热转化为有用的电能提供了一种很有前途的解决方案。高操作温度和高品质因数zT两者对于高效热电发电是期望的。在这里，我们报告了一个高的zT为1,200 K的p型FeNbSb重带半Heusler合金。高含量的较重的Hf掺杂剂同时优化电功率因数并抑制热导率。增强的点缺陷和电子-声子散射都有助于晶格热导率的显着降低。八对热电偶原型热电模块在655 K的温差下表现出6.2%的高转换效率和2.2 W cm-2的高功率密度。这些发现突出了重带热电材料的优化策略，并展示了基于低成本、优异的机械鲁棒性和稳定性的半Heusler合金的高温热电模块的现实前景。 热电材料可用于将废热转化为有用的电力，但理想的物质需要优化电功率因数并抑制导热性。在这里，作者报告了p型半赫斯勒合金FeNbSb在1,200 K时的高品质因数1.5。
Solid-state thermoelectric technology offers a promising solution for converting waste heat to useful electrical power. Both high operating temperature and high figure of merit zT are desirable for high-efficiency thermoelectric power generation. Here we report a high zT of ∼1.5 at 1,200 K for the p-type FeNbSb heavy-band half-Heusler alloys. High content of heavier Hf dopant simultaneously optimizes the electrical power factor and suppresses thermal conductivity. Both the enhanced point-defect and electron–phonon scatterings contribute to a significant reduction in the lattice thermal conductivity. An eight couple prototype thermoelectric module exhibits a high conversion efficiency of 6.2% and a high power density of 2.2 W cm−2 at a temperature difference of 655 K. These findings highlight the optimization strategy for heavy-band thermoelectric materials and demonstrate a realistic prospect of high-temperature thermoelectric modules based on half-Heusler alloys with low cost, excellent mechanical robustness and stability. Thermoelectric materials could be used to convert waste heat into useful electricity, but the ideal substance needs to both optimize the electrical power factor and suppress thermal conductivity. Here, the authors report a high figure of merit of 1.5 at 1,200 K in the p-type half-Heusler alloy FeNbSb.