In-plane lattice thermal conductivity of a quantum-dot superlattice

We have theoretically investigated the in-plane lattice thermal conductivit y of a quantum-dot superlattice. The calculations were carried out for a st ructure that consists of multiple layers of Si with randomly distributed Ge quantum dots separated by wetting layers and spacers. Our model takes into account scattering of acoustic phonons on spherical quantum dots, and corr esponding modification of the phonon dispersion relation. The finite acoust ic mismatch between Si and Ge is also taken into account. The obtained resu lts are important for the most recently suggested applications of SiGe quan tum-dot superlattices for thermoelectric devices. (C) 2000 American Institu te of Physics. [S0021-8979(00)01214-7].