A. V. Glotov

Structure and optical properties of heterostructures based on MOCVD (AlxGa1 − xAs1 − yPy)1 − zSiz alloys

Epitaxial heterostructures produced by MOCVD on the basis of AlxGa1 − xAs ternary alloys with the composition parameter x ≈ 0.20–0.50 and doped to a high Si and P atomic content are studied. Using the high-resolution X-ray diffraction technique, scanning electron microscopy, X-ray microanalysis, Raman spectroscopy, and photoluminescence spectroscopy, it is shown that the epitaxial films grown by MOCVD are formed of five-component (AlxGa1 − xAs1 − yPy)1 − zSiz alloys.

Spinodal Decomposition of GaxIn1−xAsyP1−yQuaternary Alloys

Using X-ray structural analysis, scanning electron microscopy, atomic force microscopy, and photoluminescent spectroscopy, it is shown that it is possible to obtain a small-scale domain structure on the surface of liquid-phase epitaxial heterostructures. The domain structure emerges as a result of spinodal decomposition of the GaxIn1 − xAsyP1 − y quaternary alloy due to immiscibility of its components and relaxation of its lattice parameter to surrounding layers.

Spinodal Decomposition of Ga{sub x}In{sub 1-x}As{sub y}P{sub 1-y}Quaternary Alloys

Using X-ray structural analysis, scanning electron microscopy, atomic force microscopy, and photoluminescent spectroscopy, it is shown that it is possible to obtain a small-scale domain structure on the surface of liquid-phase epitaxial heterostructures. The domain structure emerges as a result of spinodal decomposition of the GaxIn1 − xAsyP1 − y quaternary alloy due to immiscibility of its components and relaxation of its lattice parameter to surrounding layers.

The substructure and luminescence of low-temperature AlGaAs/GaAs(100) heterostructures

The substructure and luminescence of low-temperature epitaxial AlGaAs alloys are studied by Raman spectroscopy and photoluminescence spectroscopy. It is shown that the experimental data obtained in the study are consistent with the results of the previous structural and optical study. The assumption that, at high concentrations of carbon acceptors, the acceptor atoms concentrate at lattice defects of the AlGaAs crystal alloys to form carbon nanocrystals is confirmed.

Effect of silicon on relaxation of the crystal lattice in MOCVD–hydride AlxGa1 − xAs:Si/GaAs(100) heterostructures

The X-ray diffraction and infrared spectroscopy data for MOCVD-hydride AlxGa1 − xAs:Si/GaAs(100) heterostructures and homoepitaxial GaAs:Si/GaAs(100) structures doped with Si to a content of up to ∼1 at % are reported. It is shown that, in the homoepitaxial heterostructures, the formation of alloys with Si yields a decrease in the crystal lattice parameters of the epitaxial layer and a negative lattice mismatch with the single-crystal substrate (Δa < 0). At the same time, the formation of quaternary alloys in the AlxGa1 − xAs:Si/GaAs(100) heterostructures is not accompanied by any pronounced strains in the crystal lattice. By introducing Si into the epitaxial layers of these heterostructures, it is possible to attain complete matching of crystal lattice parameters of the film and substrate in the appropriately chosen technological conditions of growth of the epitaxial layers.

Structural and spectral features of MOCVD AlxGayIn1 − x − yAszP1 − z/GaAs (100) alloys

The study is concerned with MOCVD epitaxial heterostructures grown on the basis of AlxGayIn1 − x − yAszP1 − z quinary alloys in the region of alloy compositions isoperiodic to GaAs. By the X-ray diffraction technique and atomic force microscopy, it is shown that, on the surface of the heterostructures, there are nanometric objects capable of lining up along a certain direction. From calculations of the crystal lattice parameters with consideration for internal strains, it can be inferred that the new compound is a phase based on the AlxGayIn1 − x − yAszP1 − z alloy.

Structural and optical properties of low-temperature hydride-MOCVD AlGaAs/GaAs(100) heterostructures based on omission solid solutions

X-ray diffraction, scanning electron microscopy, and IR reflectance spectroscopy were used to study properties of epitaxial low-temperature hydride-MOCVD AlGaAs/GaAs (100) heterostructures. It was found that the variation in the AlGaAs alloy lattice’s parameter with Al content does not obey the classical Vegard’s law, and the lattice parameters are smaller than those of GaAs.

Relaxation of crystal lattice parameters and structural ordering in InxGa1 − xAs epitaxial alloys

Epitaxial InxGa1 − xAs/GaAs(100) heterostructures grown by the MOC-hydride method with a considerable lattice mismatch are studied by X-ray diffraction and scanning electron microscopy. The relaxation coefficient of the crystal lattice of the epitaxial alloy is calculated and the deformation energy is evaluated. It is shown that, at a concentration of the In atoms in metal sublattice close to x = 0.5, the superstructural phase formed on the surface of the epitaxial InxGa1 − xAs alloy is the InGaAs2 compound with a layered tetragonal crystal lattice and ordered arrangement of the atoms of the metal sublattice in the growth plane of the epitaxial film.

Structural and optical properties of heavily doped AlxGa1 − xAs1 − yPy:Mg alloys produced by metal-organic chemical vapor deposition

The high-resolution X-ray diffraction technique, Raman spectroscopy, and photoluminescence spectroscopy are used to study the structural, optical, and electron energy properties of epitaxial AlxGa1 − xAs1 − yPy:Mg alloy films grown by metal-organic chemical vapor deposition (MOCVD). It is shown that the introduction of a Mg impurity into the quaternary alloy provides high charge-carrier concentrations. A decrease in the growth temperature yields a decrease in the charge-carrier concentration in films doped with magnesium at a small gas-carrier flux of the acceptor impurity, whereas an increase in the flux results in an increase in the acceptor-impurity concentration, which is reflected in the character of the photoluminescence spectra.

Raman and photoluminescent spectroscopy of epitaxial heterostructures based on AlxGa1 − xAs1 − yPy solid solutions heavily doped with silicon and magnesium

The optical and energy properties of MOC-hydride AlxGa1 − xAs1 − yPy solid solutions heavily doped with silicon and magnesium are investigated by means of Raman and photoluminescent spectroscopy. It is shown that the resulting epitaxial films are multicomponent solid solutions formed by a complex mechanism.