Phonon decay in nanostructures: Computational study

Phonon dispersion relations and in core-shell quantum dot superlattices and periodic arrays of gas-filled nanopores have been computed numerically in the harmonic approximation. Core-shell quantum dot superlattices show potential to inhibit first order phonon decay. Outcomes for nanoporous systems depend strongly on surface and gas-phase interactions. Phonon decay is inhibited in idealized cases. A light absorbing material with low probability for phonon decay is critical to achieving the high efficiencies expected from the hot carrier solar cell.