Raman characterization of single defect layers embedded in finite superlattices

Single defect layers embedded in finite, nominally periodic superlattices have been examined using Raman scattering. The spectrum of zone‐folded acoustic phonons exhibits defect‐associated peaks due to the broken symmetry of the lattice. The frequencies and intensities of these additional modes can be qualitatively estimated using a simple photoelastic coupling model. Shifts in the defect mode frequencies are observed when the spatial location of the defect layer is moved from the substrate to the air interface.