Comparison of thermoelectric properties of nanostructured Mg2Si, FeSi2, SiGe, and nanocomposites of SiGe–Mg2Si, SiGe–FeSi2

• Published in: APL materials 2016-10, Vol.4 (10), p.104814-104814-9
• Main Authors: Nozariasbmarz, Amin, Roy, Palash, Zamanipour, Zahra, Dycus, J. Houston, Cabral, Matthew J., LeBeau, James M., Krasinski, Jerzy S., Vashaee, Daryoosh
• Format: Article
• Language: English
• ISSN: 2166-532X; 2166-532X
• DOI: 10.1063/1.4966138

Thermoelectric properties of nanostructured FeSi2, Mg2Si, and SiGe are compared with their nanocomposites of SiGe–Mg2Si and SiGe–FeSi2. It was found that the addition of silicide nanoinclusions to SiGe alloy maintained or increased the power factor while further reduced the thermal conductivity compared to the nanostructured single-phase SiGe alloy. This resulted in ZT enhancement of Si0.88Ge0.12–FeSi2 by ∼30% over the broad temperature range of 500-950 °C compared to the conventional Si0.80Ge0.20 alloy. The Si0.88Ge0.12–Mg2Si nanocomposite showed constantly increasing ZT versus temperature up to 950 °C (highest measured temperature) reaching ZT ∼ 1.3. These results confirm the concept of silicide nanoparticle-in-SiGe-alloy proposed earlier by Mingo et al. [Nano Lett. 9, 711–715 (2009)].