We demonstrate strain-balanced InAs/AlSb type-II superlattices (T2SL) grown on GaSb substrates employing two kinds of interfaces (IFs): AlAs-like IF and InSb-like IF. The structures are obtained by molecular beam epitaxy (MBE) for effective strain management, simplified growth scheme, improved material crystalline quality, and improved surface quality. The minimal strain T2SL versus GaSb substrate can be achieved by a special shutters sequence during MBE growth that leads to the formation of both interfaces. The obtained minimal mismatches of the lattice constants is smaller than that reported in the literature. The in-plane compressive strain of 60-period InAs/AlSb T2SL 7ML/6ML and 6ML/5ML was completely balanced by the applied IFs, which is confirmed by the HRXRD measurements. The results of the Raman spectroscopy (measured along the direction of growth) and surface analyses (AFM and Nomarski microscopy) of the investigated structures are also presented. Such InAs/AlSb T2SL can be used as material for a detector in the MIR range and, e.g., as a bottom n-contact layer as a relaxation region for a tuned interband cascade infrared photodetector.

A review of the specificity of the growth Hg1-xCdxTe layers by molecular beam epitaxy (MBE) and results of experimental studies of several Hg1-xCdxTe layers grown on CdyZn1-yTe (CZT) substrates are presented. It is well known that the performance of Hg1-xCdxTe -based detectors strongly depends on the substrate material and its orientation. CZT substrates are among the most commonly used due to their very good lattice match with Hg1-xCdxTe absorber material with different Cd content. In the present work, the authors focused on optimizing the MBE growth parameters in order to obtain the best possible crystalline quality of Hg1-xCdxTe layers grown on CZT substrates with (211)B orientation, in particular in terms of minimizing the number of defects. Experimental results of the selected structures showed that the obtained undoped Hg1-xCdxTe layers of different x have high crystallographic and optical quality, as well as good surface morphology. In particular, high-resolution X-ray diffraction (HRXRD) measurements and their analysis showed that the best structure has a full width at half maximum of rocking curve (FWHMRC) as low as 21.5 arcsec, and that the intensity distribution of diffraction peaks does not indicate the influence of mosaicisity and dislocation density.

The aim of this work was to improve the quality of the GaSb buffer layers on GaAs substrates using the molecular beam epitaxy (MBE) technology. The high quality of the GaSb buffer layers is one of the most important elements enabling the synthesis of good quality of type II superlattices (T2SL) structures for infrared applications. The main challenges in this regard are: compensation of the difference in lattice constants between GaAs and GaSb and obtaining the highest achievable surface quality of the final GaSb layer. In the literature, many authors describe different techniques to obtain the best quality of a GaSb buffer layer. In this work, we present the results of HRXRD, AFM, TOF-SIMS, SEM, and Nomarski optical microscope measurements obtained for 2 μm thick GaSb buffer layers. The GaSb layers are made according to different techniques and these results are compared with a GaSb buffer construction technique according to our own technology. During the processes, we also obtained an unintentional structure of one of the buffer layers, which allowed us to obtain very good results in terms of surface structure and crystallographic quality where FWHM in ωRC scan was equal to 138 arcsec and RMS 0.20 nm proving that there is still a lot of work to be done in this area.

In the present work, the growth specificity of Cd1−xMnxTe layers by the molecular beam epitaxy and results of experimental studies of several Cd1−xMnxTe layers grown on GaAs(100) hybrid substrates with CdTe buffers are presented. Our efforts were concentrated on creating structures with high crystallographic quality, specifically aiming to reduce the number of defects. Experimental results for the selected structures demonstrated that the Cd1−xMnxTe layers, with varying x, exhibit high crystallographic and surface morphology quality. Specifically, high-resolution X-ray diffraction measurements and their analysis revealed that the intensity distribution does not reflect the effects of mosaicity or dislocation density. The aim of the work was to characterize the Mn dopant depending on the x-value. The magnetic properties were studied as a function of manganese concentration by using electron paramagnetic resonance. By applying continuous wave electron paramagnetic resonance in the wide temperature range, we observed two groups of lines: from manganese and from so-called low field magnetic absorption.