Chen Xin, Wang Yi, Cui Tian, Ma Yanming, Zou Guangtian, Iitaka Toshiaki
National Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China.
J Chem Phys. 2008 May 21;128(19):194713. doi: 10.1063/1.2920184.
We present the calculations of the electronic structure and transport properties on the zinc-blende (ZB) and cinnabar phases of HgTe using the full-potential linearized augmented plane-wave method and the semiclassical Boltzmann theory. Our results show that n-doped cinnabar HgTe has a significant larger Seebeck coefficient and electrical conductivity along the z axis than those of the n-doped ZB phase. This is mainly attributed to the large structural anisotropy originated from its chainlike bonding characters along the z axis, resulting in the anisotropic energy distribution in the lowest conduction band of cinnabar structure. The resulting ZT values along the z axis of the n-doped cinnabar HgTe are predicted to reach very high values of 0.61 at room temperature and 1.74 at 600 K. Therefore, the current theory suggests that the cinnabar structure of HgTe could be a good thermoelectric material. Future experiments are thus demanded to explore its thermoelectric performance by making use of the high ZT.
我们使用全势线性缀加平面波方法和半经典玻尔兹曼理论，对碲化汞的闪锌矿（ZB）相和辰砂相的电子结构和输运性质进行了计算。我们的结果表明，n型掺杂的辰砂相碲化汞沿z轴的塞贝克系数和电导率比n型掺杂的ZB相碲化汞大得多。这主要归因于其沿z轴的链状键合特性所产生的大结构各向异性，导致辰砂结构最低导带中的能量分布呈现各向异性。预测n型掺杂的辰砂相碲化汞沿z轴的ZT值在室温下可达到非常高的0.61，在600 K时达到1.74。因此，当前理论表明，碲化汞的辰砂结构可能是一种良好的热电材料。因此，需要未来的实验通过利用高ZT来探索其热电性能。
