Hidden In-Plane Anisotropy of Interfaces in ZnSe/BeTe Quantum Wells with a Type-Ⅱ Band Alignment

摘要

Circularly- and linearly-polarized radiation due to spatially-indirect optical transitions is studied in ZnSe/BeTe quantum-well structureswith a type-II band alignment and very strong confinement potentials.Because of the strong in-plane anisotropy of optical matrix elements relatedto a particular interface, complete spin orientation of photocarriers inducedby magnetic fields leads not to purely circular but to elliptical polarizationof the photoluminescence. Theoretical analysis of the polarizedexperimental spectra allows one to separate effects of interface micro-(nanoscale) and macro-imperfections on the polarization and estimaterelative contributions of the normal and inverted interfaces to theluminescence.