Electronic structure of the thermoelectric materials Bi 2 Te 3 and Sb 2 Te 3 from first-principles calculations
Electronic structure of the thermoelectric materials Bi 2 Te 3 and Sb 2 Te 3 from first-principles calculations
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DOI：
10.1103/physrevb.76.075201
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发表时间：
2007-08
影响因子：
3.7
通讯作者：
Guo-feng Wang;T. Çagin
中科院分区：
文献类型：
--
作者：
Guo-feng Wang;T. Çagin
用第一性原理全势能线性化增广平面波方法计算了{{\mathm{Bi}}_{2}{\mathm{Te}}_{3}和{{\mathm{Sb}}_{2}{\mathm{Te}}_{3}}晶体的电子结构。我们不仅研究了具有实验晶格参数和标度原子坐标的非驰豫晶体，而且还研究了具有由理论结构优化确定的晶格参数和标度原子坐标的驰豫晶体。我们发现，无论驰豫程度如何，{{\mathm{Bi}}_{2}{\mathm{Te}}_{3}$都有六个最高价带边和六个最低导带边。然而，通过改变结构参数{Sb}}_{2}{\mathm{Te}}_{3}}，可能会发生价(和导电)带边数目在6到12之间变化的电子拓扑转变。此外，我们还给出了带边的位置以及与这些带边相关的电子和空穴的有效质量基数参数。此外，我们还讨论了两种晶体的计算电子结构与${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}∕{\mathrm{Sb}}_{2}{\mathrm{Te}}_{3}$超晶格电学性质的关系。
The electronic structures of ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ and ${\mathrm{Sb}}_{2}{\mathrm{Te}}_{3}$ crystals were calculated using the first-principles full-potential linearized augmented plane-wave method. We studied not only the unrelaxed crystals, which have the experimental lattice parameters and scaled atom coordinates, but also the relaxed crystals, which have the lattice parameters and scaled atom coordinates determined from theoretical structure optimizations. We found that ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ has six highest valence-band edges and six lowest conduction-band edges regardless of relaxations. However, by varying structural parameters ${\mathrm{Sb}}_{2}{\mathrm{Te}}_{3}$ may undergo an electronic topological transition that the number of valence (and conduction) band edges changes between 6 and 12. Moreover, we presented the location of the band edges and the effective mass tenor parameters for electrons and holes associated with those band edges. Furthermore, we discussed the relation of the calculated electronic structures of the two crystals with the electrical properties of ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}∕{\mathrm{Sb}}_{2}{\mathrm{Te}}_{3}$ superlattices.