Raman spectroscopy of optical phonons confined in semiconductor quantum dots and nanocrystals

Abstract

This paper gives an overview of theoretical and experimental results on Raman-active optical phonon modes confined in nearly spherical nanocrystals (NCs) of polar semiconductor materials with cubic crystal structure. A systematic consideration of the effect of reduced dimensionality on both electrons and phonons is presented. The theoretical approach is based on a continuum lattice dynamics model and the effective mass approximation for electronic states in the NCs. Calculated resonant and non-resonant Raman scattering spectra are compared to experimental data stressing the effects of phonon confinement, type of excitation, polaron correction to the exciton spectrum enhanced because of the reduced dimensionality, and individual features of the NC material. Copyright © 2007 John Wiley & Sons, Ltd.