The thermoelectric performance of InSb has been significantly improved via defect engineering or nanostructuring to reduce thermal conductivity in the past decade; however, less attention has been paid to improve its electrical properties via other key factors, e.g., carrier scattering mechanism, bipolar effect, etc. Here, we show that Bi doping on the Sb site not only significantly suppresses the high-temperature bipolar effect, but also leads to band convergence which enhances the Seebeck coefficient. As a result, a maximum zT of ∼0.43 @ 675 K is achieved in InSb_0.97Bi_0.03, which is increased by ∼43% as compared to that of pure InSb. In addition, the comparison of Bi and Ga doping (J. Mater. Chem., 2011, 21, 12398–12401) on the low-temperature electrical transport properties reveals that Bi doping is more beneficial for achieving high power factor due to the mixed acoustic phonon and ionized impurity scattering. Finally, it is suggested that Bi should be an effective dopant for electrical optimization of InSb and a further experiment on co-doping of Ga and Bi will be a considerable alternative for thermoelectric performance enhancement of InSb-based materials.

在过去的十年中，通过缺陷工程或纳米结构来降低热导率，InSb 的热电性能得到了显着改善；然而，通过其他关键因素（例如载流子散射机制、双极效应等）改善其电性能的关注较少。在这里，我们表明在 Sb 位点上的 Bi 掺杂不仅显着抑制了高温双极效应，而且导致能带收敛，从而提高了塞贝克系数。结果，在 InSb _0.97 Bi _{0.03 中}实现了 ∼0.43 @ 675 K的最大zT，与纯 InSb 相比，增加了约 43%。此外，Bi 和 Ga 掺杂 (J. Mater. Chem., 2011, 21, 12398–12401) 对低温电传输特性的比较表明，由于混合掺杂，Bi 掺杂更有利于实现高功率因数。声学声子和电离杂质散射。最后，建议 Bi 应该是 InSb 电学优化的有效掺杂剂，Ga 和 Bi 共掺杂的进一步实验将是提高 InSb 基材料热电性能的重要替代方案。