Simulated thermal conductivity of silicon-based random multilayer thin films

Reverse nonequilibrium molecular dynamics simulations have been used to quantify the impact of randomly placed mass-altered atomic planes, such as those produced in pseudomorphically grown heterostructures, on the thermal conductivity of silicon. The results indicate that the room temperature thermal conductivity of these silicon-based structures can be reduced to values below 0.050 W/m-K. These values are significantly less than those found in random alloy or superlattice structures containing the same percentage of mass-altered atoms and are attributed to Anderson localization of phonons. Such low lattice thermal conductivity in these silicon-based structures could dramatically improve the thermoelectric efficiency of this earth abundant material.