Semi-analytical prediction of phonon mean free path utilizing stochastic behavior at nanostructure interfaces

Abstract A semi-analytical method is developed to predict the phonon-boundary scattering mean free path (MFP) in nanostructured materials. Based on the segmentation of phonon displacements for each phonon collision event, the proposed solution enables us to evaluate the MFP with the geometrical and phonon-boundary scattering information of nanostructures. The validity of the method is confirmed by comparing its results with the MFP in polycrystalline nanostructures calculated using phonon transport simulations, which shows that it effectively predicts the MFP. Therefore, the proposed method can be used to efficiently determine the phonon MFP in nanostructures with sufficient accuracy.