Boltzmann Transport Equation Simulation of Semiconductor Interfacial Heat Transfer Based on Input from the Atomistic Green�s Function Method

Abstract

AbstractThe Boltzmann transport equation (BTE) had been successfully used to predict phonon transport in semiconductors including silicon and germanium. However, in a composite system, the method requires external inputs to include accurate boundary conditions at internal interfaces. The atomistic Green's function (AGF) method is particularly useful for addressing interfacial heat transfer problems. In this paper, phonon transmission functions derived using the AGF method are incorporated in a non-gray BTE calculation of phonon transport in a relaxation time approximation. A Landauer-type heat flux is computed at the interface using the transmission function and the lattice temperatures on either side of the interface to compute distribution functions. The formulation is applied to a Si/Ge interface and the dependence of the effective thermal conductivity of the composite medium is investigated as a function of domain length.