Three-phonon phase space and lattice thermal conductivity in semiconductors

Abstract

We present calculations of the phase space for three-phonon scattering events in severalgroup IV, III–V and II–VI semiconductors employing an adiabatic bond charge model toaccurately represent the phonon dispersions. We demonstrate that this phase space variesinversely with the measured lattice thermal conductivities of these materials overa wide range of temperatures where three-phonon scattering is the dominantmechanism for scattering phonons. We find that this qualitative relationship isrobust in spite of variations in material parameters between the semiconductors.Anomalous behavior occurs in three III–V materials that have large mass differencesbetween constituent elements, which we explain in terms of the severely restrictedthree-phonon phase space arising from the large gap between acoustic and optic phononbranches.