A linear dichroism study of colloidal silver in stretched polymer films

Abstract

The visible absorption spectrum of silver colloids incorporated in poly vinyl alcohol films has been resolved into five Gaussian bands of different polarization. The energy positions and relative intensities of the bands can be explained using an exciton model in which dipole-dipole coupling occurs between silver particles in a linear chain arrangement. An important conclusion that stems from the analysis is that surface-enhanced Raman scattering occurs only when the exciting light is polarized parallel to the main axis of the linear chain colloidal aggregate. © 1987.