We predict a high thermoelectric efficiency of HfTe5, based on the first-principles calculations of the electronic structure and thermal conductivity, and the transport coefficients obtained by using the semi-classical Boltzmann transport theory in a wide temperature and carrier concentration range. The lattice thermal conductivity is calculated based on the Slack model and the result is in good agreement with the experimental value. The results of all the thermoelectric transport coefficients demonstrate anisotropic characteristics with the obvious small values along with the b direction. The figure of merit ZT computed with a temperature-dependent relaxation time can reach 2.68 along with the c direction of the n-type HfTe5 at 300 K and an optimal carrier concentration of 5.801019 cm-3. The Seebeck thermopower coefficients are between 100 and 300 μV/K at the optimal carrier concentration, but can reach nearly 1000 μV/K at low concentration. Therefore, HfTe5could achieve high thermoelectric performance at room temperature by controlling the transport direction and carrier concentration.

中文翻译：

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HfTe5 室温下具有高热电品质因数和热电势


基于电子结构和热导率的第一性原理计算，以及利用半经典玻尔兹曼输运理论获得的输运系数，我们预测了 HfTe5 在较宽的温度和载流子浓度范围内具有较高的热电效率。基于Slack模型计算晶格热导率，结果与实验值吻合较好。所有热电输运系数的结果均表现出各向异性特征，沿b方向值明显较小。在 300 K 下，用与温度相关的弛豫时间计算的 n 型 HfTe5 沿 c 方向的品质因数 ZT 可以达到 2.68，最佳载流子浓度为 5.80×1019 cm-3。在最佳载流子浓度下，塞贝克热电系数在 100 至 300 μV/K 之间，但在低浓度下可以达到近 1000 μV/K。因此，通过控制输运方向和载流子浓度，HfTe5可以在室温下实现较高的热电性能。