Formation of various epitaxial nanodots in Si films for thermoelectric materials

Nanostructures are expected to enhance thermoelectric properties of Si-based materials. For enhancement, the simultaneous achievement of low κ and high σ is required. In our previous study, we have demonstrated drastic reduction of κ in Si by introducing epitaxial connected Si NDs resulting in the smallest κ in Si. We have also reported that Si films containing Ge NDsexhibited the bulk-like σ and the drastic κ reduction compared with that of bulk Si. However, S was not controlled in this nanostructure. In general, introduction of interfaces or high S materials can increase S of the total film. In addition to control of κ and σ, S can be controlled by tuning the material and size of NDs. In this work, we developed the formation method of the various material and size of introduced NDs.