Thermal investigation of nanostructured bulk thermoelectric materials with hierarchical structures: An effective medium approach
Thermal investigation of nanostructured bulk thermoelectric materials with hierarchical structures: An effective medium approach
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DOI：
10.1063/1.5006207
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发表时间：
2018-01
影响因子：
3.2
通讯作者：
Q. Hao;Hongbo Zhao;Yue Xiao;Dongchao Xu
中科院分区：
文献类型：
--
作者：
Q. Hao;Hongbo Zhao;Yue Xiao;Dongchao Xu
近年来，分级结构被广泛研究，作为一种有效的方法来定制电子和声子输运内的块体材料的热电应用。在体材料中具有原子缺陷和纳米到微米尺度的结构，可以在整个声子谱上有效地抑制晶格热导率，同时保持或稍微增强电性能。对于具有上级电性能的一般材料，使用分级结构以最小化晶格热导率可以实现高热电性能。尽管有许多令人鼓舞的实验结果，准确的晶格热导率预测仍然具有挑战性的块状材料的分层结构。在这项工作中，开发了一种有效的介质配方的纳米颗粒块体材料与嵌入式纳米结构的频率依赖的声子输运分析。用频变光子学方法验证了该公式的有效性。
In recent years, hierarchical structures have been intensively studied as an effective approach to tailor the electron and phonon transport inside a bulk material for thermoelectric applications. With atomic defects and nano- to micro-scale structures in a bulk material, the lattice thermal conductivity can be effectively suppressed across the whole phonon spectrum, while maintaining or somewhat enhancing the electrical properties. For general materials with superior electrical properties, high thermoelectric performance can be achieved using hierarchical structures to minimize the lattice thermal conductivity. Despite many encouraging experimental results, accurate lattice thermal conductivity predictions are still challenging for a bulk material with hierarchical structures. In this work, an effective medium formulation is developed for nanograined bulk materials with embedded nanostructures for frequency-dependent phonon transport analysis. This new formulation is validated with frequency-dependent pho...