Significant enhancement in thermoelectric performance of Mg3Sb2 from bulk to two-dimensional mono layer
Significant enhancement in thermoelectric performance of Mg3Sb2 from bulk to two-dimensional mono layer
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Mg3Sb2从块体到二维单层的热电性能显着增强
DOI：
10.1016/j.nanoen.2019.05.028
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发表时间：
2019-08-01
期刊：
影响因子：
17.6
通讯作者：
Shi, Jing
中科院分区：
文献类型：
--
作者：
Huang, Shan;Wang, Ziyu;Shi, Jing
热电材料能有效地将余热转化为电能，受到越来越多的关注。Zint1相Mg3Sb2是一种典型的层状热电材料，其晶体结构的各向异性导致其热电性能具有很强的各向异性。因此，多晶Mg3Sb2通常不能达到最大的热电性能。我们的研究证明，材料结构的降维不仅可以避免某些晶体方向热电性能差的问题，而且可以有效地降低晶格的热导率。在密度泛函理论的框架下，精确地研究了二维单分子膜的热电性能。在900K时，纳米薄膜的ZT值可达2.5，大于块体薄膜的ZT值。理论结果表明，纳米工程结构工艺可以显著提高热电材料的能量转换效率。
Thermoelectric materials can effectively convert waste heat into electrical energy and receive more and more attention. Zintl phase Mg3Sb2 is a typical layered thermoelectric material and the anisotropy in crystalline structure induces strong anisotropy in its thermoelectric properties. As a result, polycrystalline Mg3Sb2 usually can not achieve the maximum thermoelectric performance. Our research proves that the dimensionality reduction in material structure can not only avoid certain crystalline direction's poor thermoelectric properties but also effectively reduce the lattice thermal conductivity. Within the framework of the density functional theory, the thermoelectric performance of two-dimensional Mg3Sb2 mono layer is accurately investigated. The ZT value of the Mg3Sb2 nano-thin film can reach 2.5 at 900 K, which is larger than that of the bulk. The theoretical results indicate that the process of nano-engineered structure can significantly enhance the energy conversion efficiency of thermoelectrics.