Enhanced thermoelectric performance of nanostructured topological insulator Bi2Se3
Enhanced thermoelectric performance of nanostructured topological insulator Bi2Se3
复制标题
纳米结构拓扑绝缘体 Bi2Se3 的增强热电性能
DOI：
10.1063/1.4907252
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发表时间：
2015-02-02
影响因子：
4
通讯作者：
Li, X. J.
中科院分区：
文献类型：
--
作者：
Sun, G. L.;Li, L. L.;Li, X. J.
利用拓扑绝缘体的拓扑特性来提高热电性能已引起人们的广泛关注。在这里，我们表明，随着晶粒尺寸从微米减小到厚度接近80 nm，电子迁移率μ从12-15 cm（2）v（-1）s（-1）急剧增加到接近600 cm（2）v（-1）s（-1），这是由于拓扑保护导电表面的贡献增加。同时，由于增加的晶界增强的声子散射，其晶格热导率降低了约30%-50%。结果，所有细晶粒样品的热电优值ZT得到改善。具体地，对于Bi 2Se 3，在T =类似于570 K时实现ZT =类似于0.63的最大值。(C)2015 AIP Publishing LLC.
To enhance thermoelectric performance by utilizing topological properties of topological insulators has attracted increasing attention. Here, we show that as grain size decreases from microns to similar to 80 nm in thickness, the electron mobility mu increases steeply from 12-15 cm(2) v(-1) s(-1) to similar to 600 cm(2) v(-1) s(-1), owing to the contribution of increased topologically protected conducting surfaces. Simultaneously, its lattice thermal conductivity is lowered by similar to 30%-50% due to enhanced phonon scattering from the increased grain boundaries. As a result, thermoelectric figure of merit, ZT, of all the fine-grained samples is improved. Specifically, a maximum value of ZT = similar to 0.63 is achieved for Bi2Se3 at T = similar to 570 K. (C) 2015 AIP Publishing LLC.