TY - JOUR A1 - Motyka, Marcin A1 - Sęk, Grzegorz A1 - Ryczko, Krzysztof A1 - Dyksik, Mateusz A1 - Weih, Robert A1 - Patriarche, Gilles A1 - Misiewicz, Jan A1 - Kamp, Martin A1 - Höfling, Sven T1 - Interface Intermixing in Type II InAs/GaInAsSb Quantum Wells Designed for Active Regions of Mid-Infrared-Emitting Interband Cascade Lasers JF - Nanoscale Research Letters N2 - The effect of interface intermixing in W-design GaSb/AlSb/InAs/Ga\(_{0.665}\)In\(_{0.335}\)As\(_x\)Sb\(_{1-x}\)/InAs/AlSb/GaSb quantum wells (QWs) has been investigated by means of optical spectroscopy supported by structural data and by band structure calculations. The fundamental optical transition has been detected at room temperature through photoluminescence and photoreflectance measurements and appeared to be blueshifted with increasing As content of the GaInAsSb layer, in contrast to the energy-gap-driven shifts calculated for an ideally rectangular QW profile. The arsenic incorporation into the hole-confining layer affects the material and optical structure also altering the InAs/GaInAsSb interfaces and their degree of intermixing. Based on the analysis of cross-sectional transmission electron microscopy images and energy-dispersive X-ray spectroscopy, we could deduce the composition distribution across the QW layers and hence simulate more realistic confinement potential profiles. For such smoothed interfaces that indicate As-enhanced intermixing, the energy level calculations have been able to reproduce the experimentally obtained trend. KW - FTIR spectroscopy KW - type II GaIn(As)Sb/GaSb KW - QW interface profile KW - intermixing KW - interband cascade lasers KW - EDX spectra Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-136386 VL - 10 IS - 471 ER -