Influence of the structural defects on localized interface optical-phonon modes in periodically layered heterostructures

Abstract

The existence and characteristics of the localized interface optical-phonon modes in periodically layered heterostructures with a defect layer consisting of ternary mixed crystal Al x Ga 1− x As are studied in the dielectric continuum approximation. A comparison of the localized and extended interface optical phonon modes between the presented structure and GaAs/AlAs superlattice structure with defect layers is addressed. We find that the frequencies and localization degree of the localized modes depend on the concentration and thickness of the defect layer. Specially, the symmetric localized modes are more sensitive to the concentration of the defect layer than the antisymmetric modes. It is expected that the localized modes can be artificially controlled by adjusting the parameters of the presented micro-structures.