Nanophononics: Fine-tuning phonon dispersion in semiconductor nanostructures

Abstract

Phonons manifest themselves in all electrical, thermal, optical and noise phenomena in semiconductors. Reduction of the feature size of electronic devices below the acoustic phonon mean free path creates a new situation for the phonon transport. On the one hand, the phonon– rough boundary scattering complicates heat removal from the downscaled devices. On the other hand, spatial confinement of the acoustic phonons creates an opportunity for intelligent tuning of the phonon dispersion in semiconductor nanostructures and achieving enhanced operation of devices based on these nanostructures. This paper presents a brief review of the recent developments in the field of nanophononics. Specifically, it focuses on methods of tuning the phonon spectrum in acoustically mismatched nano- and heterostructures in order to change the electron mobility and phonon thermal conductivity.