Size-selective resonant Raman scattering in CdS doped glasses

The size and excitation dependence of resonant low-frequency Raman scattering in CdS nanocrystals (radii less than 10 nm) embedded in a glassy matrix have been investigated. We report a size-selective excitation for excitations inside the absorption features. The Raman spectra exhibit a different behavior when the excitation is below the absorption band. This behavior is shown to depend on the fabrication process of the samples and is assigned to a resonance on surface defects.