A study of iron-doped SiGe growth for thermoelectric applications

Silicon-germanium (SiGe) alloy has been studied for thermoelectric (TE) generators for decades due to its hightemperature stability. However, its low TE performance at a low temperature still needs to be solved. Nanoinclusion improves the TE performance, but the material and processing costs are still high. Here, we proposed a method by embedding silicide during crystal growth; in-situ observation at different cooling rates was carried out. At a 100 K/min cooling rate, a SiGe alloy containing & alpha;-FeSi2 precipitates was grown, which yielded a relatively low lattice thermal conductivity & kappa;lat of 4.80 Wm � 1K-1 and a good zT value of 0.08 at room temperature. This was comparable to the commercial SiGe alloy, but the germanium used was reduced by 25%, and the process was much faster.