InAs/GaSb/AlSb composite quantum well structure preparation with help of reflectance anisotropy spectroscopy

Magnetotransport, optical, spin-dependent and topological properties of the composite InAs/GaSb/AlSb quantum wells based on the broken-gap heterojunctions have been actively studied during the last two decades as promising materials for spintronic and nanoelectronic applications. Mostly the structures were prepared by MBE, since preparing heterostructures of this materials system by MOVPE presents several challenges. We have successfully prepared by MOVPE structures with broken gap InAs/GaSb composite quantum wells surrounded by AlSb barriers on InAs and GaSb substrates. The whole process of structure preparation was optimized with help of in situ LayTec Epiras measurements. Suitable interfaces, switching sequences, growth rates and suitable precursors for the growth of the structure are discussed. The quality of the structure was checked by electron paramagnetic resonance for differently oriented magnetic field up to 14 kOe at temperatures from 2.7K to 20 K. Intense Shubnikov de Haas oscillations appeared at low temperatures and helped us characterize the properties of the structure.