Raman-scattering study of exciton-phonon coupling in PbS nanocrystals

Abstract

The exciton-phonon coupling strength of PbS nanocrystals that strongly confine both charge carriers is investigated using resonant Raman scattering. The strength of this coupling (Huang-Rhys parameter S∼0.7) is four orders of magnitude greater than that predicted theoretically for the intrinsic states of the nanocrystal, but is the same order of magnitude as that measured for Cd(S,Se) nanocrystals. The large exciton-phonon coupling is consistent with one charge carrier being localized at the surface of the nanocrystal.