Observation of Coupled Vibrational Modes of a Semiconductor Nanocrystal

Abstract
Raman scattering and far-infrared absorption spectra of PbS nanocrystals with radii of 2 nm are presented. The experimental results are consistent with theoretical calculations which account correctly for the mechanical boundary conditions at the nanocrystal-host interface, and include the first observation of the mixed or coupled vibrational modes predicted by the theory.