Acoustic phonon problem in nanocrystal–dielectric matrix systems

It has been shown that the energy spectrum of acoustic phonons in semiconductor quantum dots (QDs) embedded in a dielectric matrix is continuous despite the three-dimensional spatial confinement. This immediately follows from the analysis of the vibrational spectrum of such composite material, treating the QDs and host matrix as a unified system. Then, the confinement only modifies the acoustic phonon wave functions in QDs as compared to the bulk. From this point of view the phonon sideband structure in optical spectra of the QDs has been analyzed.