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The results of optimization of the design and growth conditions of an In x Al1–xAs metamorphic buffer layer with a high In content (x = 0.05–0.83) grown via MBE on GaAs(001) substrates with the purpose of optimizing its surface morphological characteristics and structural properties and lowering the surface density of threading dislocations. The lowest surface-pattern roughness RMS = 2.3 nm (on an area of 10 × 10 μm) and density of threading dislocations of 5 × 107 cm–2 are found in the samples with a convex-graded metamorphic buffer layer.

We report on molecular beam epitaxial growth and properties of InAs/In 0.66 Ga 0.34 As/In 0.77 Al 0.23 As metamorphic quantum wells (QWs) with submonolayer InSb insertions grown on GaAs(0 0 1) substrates. InAlAs metamorphic buffer layers with linear and convex profiles are used to match gradually the lattice parameter from GaAs one to that of In 0.77 Al 0.23 As barriers, with the latter profile showing the better structural quality. A single type-II InSb insertion in the InAs QW shifts the photoluminescence (PL) peak maximum well beyond 3 μm due to the recombination of holes localized in the InSb well with electrons confined in the InAs/InGaAs QW. The mid-infrared PL in the structures with and without InSb insertion survives up to room temperature.

Raman scattering effects have been used to study phonon properties of complex multilayer (In, Ga, Al) (As, Sb) heterostructures with InAs quantum wells grown by molecular beam epitaxy on GaAs and GaSb substrates. Raman scattering in the region of folded acoustic phonons gives information on the periodicity of cladding superlattices and the abruptness of their interfaces. Raman scattering by InAs phonon modes due to an InAs quantum well are strongly enhanced under optical excitation in resonance with the E1 band gap of InAs. Interface modes of InSb are detected in resonant Raman scattering, in agreement with the intended interface bond controlled by the beam supply sequence during growth. Resonant excitation results also in the observation of Raman scattering by a collective intersubband plasmon mode due to a two dimensional electron gas in the InAs quantum well. It is shown that a detailed analysis of complex multilayer structures can be performed based upon resonant Raman experiments which agrees fairly well with double crystal x-ray diffraction and galvanomagnetic studies.

We report growth as well as optical and structural studies of a new type of a GaAs/GaSb heterostructure, with 1–3 monolayer thick GaAs layers embedded within unstrained GaSb. In such structures the GaAs layer is under tensile stress, in contrast to the situation in which self-organized growth of quantum dots is commonly observed. The structure emits light in the 2 μm wavelength range. The emission characteristics are explained by a combination of quantum confinement effects and localization on nanoscale potential fluctuations.

This paper reports the effect of growth parameters and buffer structure on the luminescence electrical and structural characteristics of thin (