Lattice thermal conductivity of semiconducting bulk materials: atomistic simulations

Abstract

This paper presents a theoretical investigation of the microscopic mechanisms responsible for heat transport in bulk Si, Ge and SiGe alloys, with the goal of providing insight into design rules for efficient Si-based nanostructured thermoelectric semiconductors. We carried out a detailed atomistic study of the thermal conductivity, using molecular dynamics and the Boltzmann transport equation. We investigated in detail the effects of the physical approximations underlying each approach, as well as the effect of the numerical approximations involved in the implementation of the two different methods. Our findings permitted us to understand and reconcile apparently conflicting results reported in the literature.