Interface effects in the Raman scattering of InN/AlN superlattices - art. no. 153314

摘要

Calculations of the Raman spectra of zinc blende InN/AlN superlattices were carried out assuming the existence of interface regions with thickness delta varying from zero to three monolayers. The optical branches were greatly affected by interfacing, while the acoustic branches remained practically unchanged. Frequency shifts up to 80 cm(-1) were observed for some of the optical frequencies when delta=3. The higher frequency peaks were observed to shift downward with increasing the interface thickness. Many peaks appearing at the low frequency side shift toward the center position of the spectrum. As a consequence, pairs of the Raman modes become quasidegenerate giving rise to highly prominent structures in the spectrum for delta=2 and 3. Effects of localization of atomic displacements at the interface regions are shown. [References: 32]