TY  - JOUR
A1  - Dyksik, Mateusz
A1  - Motyka, Marcin
A1  - Sęk, Grzegorz
A1  - Misiewicz, Jan
A1  - Dallner, Matthias
A1  - Weih, Robert
A1  - Kamp, Martin
A1  - Höfling, Sven
T1  - Submonolayer Uniformity of Type II InAs/GaInSb W-shaped Quantum Wells Probed by Full-Wafer Photoluminescence Mapping in the Mid-infrared Spectral Range
JF  - Nanoscale Research Letters
N2  - The spatial uniformity of GaSb- and InAs substrate-based structures containing type II quantum wells was probed by means of large-scale photoluminescence (PL) mapping realized utilizing a Fourier transform infrared spectrometer. The active region was designed and grown in a form of a W-shaped structure with InAs and GaInSb layers for confinement of electrons and holes, respectively. The PL spectra were recorded over the entire 2-in. wafers, and the parameters extracted from each spectrum, such as PL peak energy position, its linewidth and integrated intensity, were collected in a form of two-dimensional spatial maps. Throughout the analysis of these maps, the wafers' homogeneity and precision of the growth procedure were investigated. A very small variation of PL peak energy over the wafer indicates InAs quantum well width fluctuation of only a fraction of a monolayer and hence extraordinary thickness accuracy, a conclusion further supported by high uniformity of both the emission intensity and PL linewidth.
KW  - interband cascade lasers
KW  - fourier transform spectroscopy
KW  - mid-infrared
KW  - type II quantum wells
KW  - spatially resolved photoluminescence
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-139733
VL  - 10
IS  - 402
ER  - 
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  -