Thermoelectric properties and morphology of Si-Ge-Au amorphous thin films with superior performance at near room temperature

In this paper, we report the recrystallization process of Si-Ge-Au amorphous thin film with extremely large thermoelectric power that was prepared in ultra high vacuum. We observed the morphology of samples by using FE-SEM and FE-TEM. We found that the power factor increased at near room temperature for high Au concentration samples. But after several annealing cycles, segregations were observed on high Au concentration samples. The diameter reached 30 μm at maximum on 300 nm thickness thin film. These segregations were two types. One type was Au segregation and the other was Si-Ge segregation.