Acoustic phonon engineering of thermal properties of silicon-based nanostructures

We have theoretically studied the influence of the nanostructure cladding materials on the phonon thermal conduction in the Si-based planar heterostructures and rectangular hetero-nanowires. The phonon energy spectra were obtained in the framework of the face-centered cell-dynamic lattice model. Using this model we have shown that the nanostructure claddings with the low sound velocity decrease the phonon group velocities and thermal conductivity in the nanostructures, while the claddings with high sound velocities have the opposite effect. The described modification of the thermal conductivity of the semiconductor nano- and heterostructures may have important consequences for electronic industry in a view of continuing miniaturization.