Higher order zone-folded modes in ZnSe-ZnS strained-layer superlattices

Abstract
Higher order (up to the 5th order) zone-folded acoustic modes in ZnSe-ZnS strained-layer superlattices (SLSs) were observed by means of Raman scattering. Structural characterization of both periodicity of superlattices and roughness of the interface was done by means of transmission electron microscopy (TEM). The Raman spectrum of zone-folded modes was well explained by the theoretical calculation which takes account of two observed structural characteristics of the sample, the periodicity of the superlattices, and the roughness of the interface. This clearly shows the strain does not matter to the observation of the zone-folded modes