Monte Carlo simulation of thermoelectric properties in nanocomposites

This paper presents a Monte Carlo simulation scheme to study the thermoelectric properties of nanocomposites with special attention paid to the implementation of periodic boundary condition in Monte Carlo simulation. The scheme is applied to study the thermal conductivity of silicon germanium (Si-Ge) nanocomposites, which are of great interest for high efficiency thermoelectric material development. The size effects of phonon transport in nanoparticle composites were studied and the results show that the thermal conductivity of nanoparticle composites can be lower than alloy value. It was found that randomly distributed nanoparticles in nanocomposites rendered the thermal conductivity values very close to that of nanocomposites with periodically aligned mono-size nanoparticles. This suggests that interfacial area per unit volume is a useful parameter to correlate the size effect of thermoelectric properties in nanocomposites.