Enhanced thermoelectric power factor of p-type Mg3Sb2 via co-doping of Si and Fe

Abstract

Mg3Sb2-based Zintl compounds are well known as an intrinsic p-type narrow bandgap semiconductor which can be considered as promising candidates because of their non-toxic and inexpensive elements. In this study, Mg3Sb2 compounds doped with Si and co-doped with Fe and Si have been successfully prepared by solid phase reaction method (Combination of high energy ball milling, hot pressing, and sintering). The thermoelectric properties of Si-doped and (Fe, Si) co-doped on the Sb sites of Mg3Sb2 compounds were investigated in the temperature range of 300-673K. The secondary phases of SiSb3 and FeSb were found in the doping samples. The thermoelectric results showed that the electrical conductivity strongly increased in Si-doped sample, while the additional Fe doping further enhanced the Seebeck coefficient compared to undoped Mg3Sb2 sample. The highest power factor value was observed in co-doped Fe, Si sample. Maximum value of the power factor in Mg3Sb1.4Fe0.5Si0.1 was 1.8 μWcm-1K-2 at 673K, which is around ~ 2.2 times higher than that of the undoped sample.

Keywords

• bán dẫn
• đồng pha tạp
• mg3sb2
• vật liệu nhiệt điện