Abstract

Due to the sizably larger direct band gap of 2.26 eV of AlSb, the thermoelectric properties of intrinsic AlSb is considerably low. Despite a promising Seebeck coefficient, the low electrical conductivity and high thermal conductivity has limited the improvement of thermoelectric figure of merit. Replacing small amounts of Al by Mg can increase the number of holes in the solid-state, effectively helping tune the carrier concentration. This work explores the effect of Mg doping in AlSb. The incorporation of Mg at Al sites has increased the electrical conductivity without decreasing the Seebeck coefficient detrimentally. The thermoelectric figure of merit has shown improvement despite the large thermal conductivity observed. The work additionally explores the possibility of improving thermoelectric properties further by forming a composite with β-Zn₄Sb₃. The highest thermoelectric figure of merit was found to be 0.075 at 873 K, which is 6 times higher than that in intrinsic AlSb.

Graphic Abstract

中文翻译：

---

通过掺入镁作为p型掺杂剂来改善AlSb的热电性能

摘要

由于AlSb的直接带隙较大，为2.26 eV，因此本征AlSb的热电性能非常低。尽管塞贝克系数有希望，但低电导率和高热导率限制了热电品质因数的提高。用镁代替少量的铝可以增加固态中的空穴数量，有效地帮助调整载流子浓度。这项工作探讨了AlSb中Mg掺杂的影响。在Al位点处掺入Mg增加了电导率，而没有不利地降低塞贝克系数。尽管观察到大的热导率，热电品质因数已经显示出改善。这项工作还探索了通过与β-Zn形成复合材料进一步改善热电性能的可能性₄ Sb ₃。发现最高热电性能因数在873 K为0.075，比本征AlSb高6倍。

图形摘要