An experimental study of optical phonon modes, both confined and interface phonons, in bilayer strain‐coupled quantum dot (QD) heterostructures has been presented by means of low‐temperature polarized Raman scattering. This work attributes the most intense peaks as longitudinal optical mode (LO), transverse optical modes modes, and QD LO modes. The effect of ‐content on the wavenumber positions of these phonon modes has been very well correlated with the simulated strain. The Raman peaks show slightly different wavenumber shifts in the heterostructure with varying ‐content in the capping layer. They are right‐shifted to higher energy in sample B ( ‐content) compared to sample A (having ‐content). This shift is attributed to the strain relaxation of the heterostructure due to bigger size of the QDs.
Kumar et al. (Wed,) studied this question.