The Nanometer-Sized Eutectic Structure of Si/CrSi2 Thermoelectric Materials Fabricated by Rapid Solidification

摘要

Nanostructuring is known to be an effective method to improve thermoelectric performance but, generally, it requires complex procedures and much labor. In the present study, self-assembled nanometer-sized composite structures of silicon (Si) and chromium disilicide (CrSi2) were easily fabricated by the rapid solidification of a melt with a eutectic composition. Ribbon-like samples were obtained with a dominant nanostructure of fine aligned lamellae with a spacing range of 20-35 nm. The thermoelectric power factor of the ribbon was observed to be 1.2 mW/mK(2) at room temperature and reached 3.0 mW/mK(2) at 773 K. The thermal conductivity was 65% lower than that of a bulk eutectic sample. The results suggest that this method is promising for fabricating an effective nanostructure for thermoelectric performance.