The techniques of size reduction and defect engineering have attracted great interest as an effective strategy for developing new and modified thermoelectric materials with high performance. Here, we investigated the thermoelectric properties of the Bi₂Te₃ system modified by Fermi level tuning through the methods of nanostructuring and doping. Band structure modification and Fermi level shift contribute to the better thermoelectric performance of the material. A minimum thermal conductivity of 0.72 W K⁻¹ was obtained at 440 K with a reduction of 50% as compared to the pristine sample. The improved transport properties along with considerably reduced thermal conductivity result in a two-fold improved figure of merit of 0.295 at 420 K for the nanostructured sample Bi_0.4Sb_1.6Te₃ over pristine Bi₂Te₃.

中文翻译：

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用于热电应用的改进 Bi2Te3 系统中的费米能级调谐

尺寸减小和缺陷工程技术作为开发高性能新型和改性热电材料的有效策略引起了极大的兴趣。在这里，我们通过纳米结构和掺杂的方法研究了费米能级调谐修饰的Bi ₂ Te ₃体系的热电性能。能带结构修改和费米能级位移有助于材料更好的热电性能。^{0.72 WK -1}的最小热导率与原始样品相比，在 440 K 下获得了 50% 的减少量。_{对于纳米结构样品 Bi 0.4} Sb _1.6 Te ₃，与原始 Bi ₂ Te ₃相比，改进的传输特性以及显着降低的热导率导致在 420 K 时的品质因数提高了两倍，为 0.295 。