EFFECTS OF CONFINEMENT AND SURFACE RECONSTRUCTION ON THE LATTICE DYNAMICS AND THERMAL TRANSPORT PROPERTIES OF THIN FILMS

摘要

Phonon transport in argon and silicon thin films is examined using harmonic lattice dynamics theory and the Lennard-Jones and Stillinger-Weber potentials. Film thicknesses ranging from 0.8 to 33.5 nm for argon and 0.4 to 8.6 nm for silicon are examined at a temperature of 0 K. Both reconstructed films and films built using the bulk unit cell are considered. Phonon dispersion curves for the in-plane direction and the density of states are computed from lattice dynamics and compared to predictions for a bulk system. The results from the lattice dynamics calculations are used to predict the thermal conductivities of the bulk and thin film structures.