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The peculiarity of planar quantum magnetotransport in the type II broken-gap p-GaInAsSb/p-InAs heterostructures at high magnetic fields has been investigated. The structure of the hybridized energy spectrum of a two-dimensional semimetal channel at a single type II broken-gap heterointerface was considered in dependence on the composition of the quaternary solid solution. A transition from a conducting state to a dielectric state (quantum insulator) for a 2D-semimetal channel at the heteroboundary was observed in quantizing magnetic fields under the condition of simultaneous filling of the first Landau levels for 2D-electron and interface hole states. [ABSTRACT FROM AUTHOR]

Uniform arrays of the InSb quantum dots with a surface density of nQD = 2 × 109 cm–2 were obtained by liquid phase epitaxy on a matrix layer based on a multicomponent InGaAsSb solid solution lattice-matched with the GaSb substrate. The change in the composition of the cationic part of the matrix by using the epitaxial matrix layer allowed to lower the temperature of the epitaxy to T = 430°C and determined the shape of a typical InSb quantum dot in the form of a truncated cone with average values of height h = 3 nm and diameter d = 30 nm, which corresponded to the aspect ratio L = h/d = 0.1. [ABSTRACT FROM AUTHOR]

Photoluminescence (PL) has been observed at room temperature from a Ga0.96In0.04As0.11Sb0.89quaternary solid solution for the first rime. High-quality epitaxial layers of n-type (Te-doped) Ga0.96In0.04As0.11Sb0.89 with low In content were grown by liquid phase epitaxy (LPE) lattîce-matched to InAs(100) substrates from a Ga-rich melt. The PL properties of the material were investigated over a wide temperature range, and the principal radiative transitions were identified. In the temperature range <150 K, donor-acceptor recombination involving the first and second ionization state of native antisite defects was the dominant radiative-recombination process, whereas interband recombination was found to dominate at room temperature. [ABSTRACT FROM AUTHOR]

Epitaxial layers of phosphorus-rich InAs[sub 1-y-x]Sb[sub y]P[sub x] solid solutions were obtained by liquid phase epitaxy (LPE). The films with x = 0.32 were grown at 575°C on isoperiodic (100)InAs substrates. It is shown that the growth of InAsSbP layers from a phosphorus-rich liquid phase is accompanied by saturation of the phosphorus content in the solid state. InAsSbP-based diode heterostructures emitting in the 2.6-2.8 µm wavelength range were obtained, the output emission power of which is sufficient for detecting both natural and industrial gases in the atmosphere. [ABSTRACT FROM AUTHOR]

Photoluminescence of Ga[sub 1-x]In[sub x]As[sub y]Sb[sub 1-y] (0.08 < x < 0.22) epilayers lattice-matched to InAs substrate was investigated for the first time at 80 K, and the band gap of solid solutions was evaluated experimentally. It was demonstrated that the intensity of the band-to-band radiative recombination for p-GaInAsSb undoped layers depends on the composition of the quaternary solid solution and is governed by the concentration of intrinsic structural defects. For an n-GaInAsSb:Te donor-doped layer, the band-to-band recombination band and an additional emission band were observed. The latter band is related to the radiative recombination via the deep acceptor level formed by an intrinsic complex V[sub Ga]Te with the activation energy E[sub DA] = 122 meV. [ABSTRACT FROM AUTHOR]

High-quality type II Ga[sub 0.83]In[sub 0.17]As[sub 0.22]Sb[sub 0.78]/InAs heterostructures based on GaSb-rich quaternary solid solutions were grown by liquid phase epitaxy on InAs(001) substrates. GaInAsSb epilayers were grown under planar two-dimensional growth conditions with abrupt and planar interfaces. The thickness of the transition layer on the Ga[sub 0.83]In[sub 0.17]As[sub 0.22]Sb[sub 0.78]/InAs interface enriched with In and Sb was 10-12 Å in perfect structures. The roughness of the upper boundary was entirely determined by the epitaxial-growth conditions and did not exceed 500 Å in structures with a layer thickness of about 2 µm. [ABSTRACT FROM AUTHOR]

Galvanomagnetic phenomena and photoconductivity in broken-gap type-II GaInAsSb/p-InAs heterojunctions with different levels of doping of the solid solution with donor (Te) or acceptor (Zn) impurities have been investigated. It has been determined that in such structures an electronic channel, which determines the galvanomagnetic effects in a wide range of doping levels, is present at the heterojunction. A sharp decrease of the Hall mobility was observed in the experimental heterostructures with a high level of doping of the epitaxial layer with an acceptor impurity. The observed effect is due to exhaustion of the electronic channel as a result of carrier localization in potential wells at the heterojunction. [ABSTRACT FROM AUTHOR]

The diagrams of melt-solid solution (fusibility curves) and solid solution (I)-solid solution (II) (surfaces of spinodal decomposition of solid solutions) phase equilibria in the fivecomponent system In-Ga-As-Sb-P (the solid solutions are isoperiodic to the GaSb and InAs substrates) are calculated. The concentration ranges of the isovalent substitution solid solutions In[sub x]Ga[sub 1-x]As[sub y]Sb[sub z]P[sub 1 - y - z], which are accessible for synthesis by liquid-phase epitaxy, are calculated. [ABSTRACT FROM AUTHOR]

Low-temperature photoluminescence (PL) study of liquid phase epitaxy grown undoped and Sn doped GaIn[sub 0.16]As[sub 0.22]Sb layers lattice matched to InAs is reported. The quaternary solid solutions Ga[sub 1-x]In[sub x]As[sub y]Sb[sub 1-y] are promising materials for the fabrication of optoelectronics devices operating in the spectral range 3–5 μm because these alloys can form type II heterojunctions both with staggered and broken-gap alignment. The band structure engineering of these devices requires the knowledge of energy gaps and mechanism of radiative recombination transitions in the forbidden gap of cladding layers. The high quality quaternary GaIn[sub 0.16]As[sub 0.22]Sb epitaxial layers with low native defect concentration were grown lattice matched to InAs and their photoluminescence was studied at low temperatures. The emission band related to bound exciton was dominant. While the emission bands associated with the first ionization state of V[sub Ga]Ga[sub Sb] vacancy-antisite defect with activation energy ΔE[sub A]=22 meV and unknown deep defect with ΔE[sub B]=46 meV were found besides the main PL peak ΔE[sub BE]=16 meV. It was established that Sn as an amphoteric impurity can form shallow donor levels. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Temperature dependence of the energy gap and the spin-orbit split off transition in a thick layer of narrow-gap InGaAsSb material with high In content has been determined by a combination of photoluminescence and photoreflectance. The respective temperature coefficients have been found to be equal for both the transitions and determined to be α = -0.41 meV/K. For the investigated In0.86Ga0.14As0.83Sb0.17 alloy, the separation energy of the split-off band has been obtained to be Δso = 0.460 eV and experimentally evidenced to be independent on temperature, which opens broad application prospects for these multinary (multicomponent) narrow gap compounds and their heterostructures. [ABSTRACT FROM AUTHOR]