Magnetotransport properties of the narrow-gap In x Ga 1− x As y Sb 1− y /GaSb heterojunctions grown by liquid-phase epitaxy with various In content in the solid solution ( x =0.85–0.95 and E g ≤0.4 eV) were studied. It is shown that, depending on the In content in these heterostructures, type II staggered-lineup ( x =0.85) or broken-gap heterojunctions ( x =0.95) with high mobility in the electron channel at the interface (μ⋍20000 cm 2 /(V s)) can be realized. For x =0.92, depending on temperature, both types of heterojunctions were observed. Obtained results are in good agreement with the band energy diagram of the type II InGaAsSb/GaSb heterostructures under study.

Light-emitting diode structures operating at room temperature were obtained based on a p -AlGaAsSb/ n -InGaAsSb/ n -AlGaAsSb heterostructure with high Al content in the boundary layers formed on a p -GaSb(100) substrate. This structure ensures a threefold increase in the output radiant power and the external quantum yield (∼1%) as compared to the known InAsSb/InAsSbP heterostructure grown on an InAs substrate. A considerable increase in the pulsed output radiant power is explained by a more effective confinement of nonequilibrium charge carriers in the active region and by a decrease in the nonradiative recombination level, which is achieved by creating an isoperiodic structure.

Magnetotransport properties of an electron channel at the heteroboundary in type II separated p-Ga1−xInxAsySb1−y/p-InAs heterostructures grown by LPE (x=0.09–0.22) were studied in the temperature range of 77–300 K. It is shown that an electron channel, which is formed at the heteroboundary and has high mobility μ=(3–5)×104 cm2 V−1 s−1, exists throughout the whole composition range. The band diagram of the heterostructures under study is discussed, and some parameters of the electron channel are evaluated. It is found that the electron channel with high mobility persists up to room temperature. Type II GaInAsSb/p-InAs heterostructures can find application in new Hall sensor devices with an electron channel at the heteroboundary.

The electrical properties of epitaxial InAs and solid solutions based on it (InGaAsSb, InAsSbP, InAsGa, InAsP) have been investigated. It is shown that intentionally undoped crystals have n-type conductivity, which is determined by shallow donor impurities (E1=0.002–0.003 eV) and structural defects (E2=0.02–0.03 eV and E3=0.09–0.10 eV). It is shown that growth of epitaxial InAs using the neutral solvent Pb and also rare-earth elements makes it possible to reduce the electron density by almost an order of magnitude (to levels as low as 3×1015 cm−3) due to due to a decrease in the density of structural defects.

We have studied experimentally the magneto-transport properties of type-II broken-gap Ga1 − xInxAsSb/p-InAs heterostructures with various doping levels of the quaternary layer by Te or Zn. A strong electron channel with high electron mobility was observed at the interface of the heterostructures. Interface roughness scattering was found to dominate the electron mobility atT = 4.2–47 K in samples with an undoped or a slightly doped quaternary layer. A drastic mobility drop with increasing Zn doping level was observed. Shubnikov–de Haas oscillations at low temperatures (1.5–20 K) were studied and a weak anisotropy of magnetoresistance was found. Some important parameters of the heterostructures under study were determined.

An investigation is carried out on the properties of the electron channel in a broken-gap isotypic type II GaInAsSb/p-InAs heterostructure and their dependence on the doping level of the quaternary solid solution with a donor (Te) and an acceptor (Zn). The Hall mobility decreases (by more than two orders of magnitude) with increasing acceptor concentration. The Shubnikov-de Haas oscillations are observed at low temperatures (T=1.5–20 K) and the electron effective mass is determined (mn=0.026m0), along with some other parameters of the heterostructure.