Molecular dynamics study on phonon coherent transport in III-V semiconductor superlattices

Abstract

Understanding heat transport in superlattices is essential for optimizing thermal management in semiconductor chips and related devices. Coherent phonon transport, a wave-based thermal transport mechanism, can reduce phonon scattering at superlattice interfaces, thereby enhancing thermal conductivity. Here, we investigate phonon coherent transport in (AlAs)n/(InAs)n superlattices using first-principles calculations and molecular dynamics simulations based on machine learning potential functions. Our findings reveal that phonon coherent transport in the (AlAs)n/(InAs)n superlattice can be sustained over long distances of approximately 18.9 nm, even at room temperature. The phonon band folding effect, induced by the superlattice structure, simultaneously reduces the phonon group velocities and lifetimes, which plays an important role in phonon coherent transport. This work deepens the understanding of heat transport in III-V semiconductor superlattices and other similar materials.