SiGe nanocomposites: novel materials with very low lattice thermal conductivity for efficient thermoelectric conversion

Within a materials-by-design paradigm we make use of large-scale atomistic simulations to tailor the structural and chemical characteristics of SiGe nanocomposites so as to get poor thermal conductors useful for efficient thermoelectric energy production. Simulations provide evidence that thermal transport only marginally depends on stoichiometry, while it is deeply affected by granulometry. The main role in affecting thermal conduction by grain boundaries is enlightened, which largely affect vibrational modes with long mean free path.