Eugene A. Emelyanov

Formation and crystal structure of GaSb/GaP quantum dots

The atomic structure of GaSb/GaP quantum dots grown via molecular beam epitaxy on a (100) GaP surface at epitaxy temperatures of 420–470°C is investigated. It is established that, depending on morphology of the GaP growth surface, the deposition of 1 ML of GaSb leads to the formation of strained Ga(Sb, P)/GaP or fully relaxed GaSb/GaP quantum dots. The obtained heterostructures exhibit high photoluminescence efficiency.

Formation of low-dimensional structures in the InSb/AlAs heterosystem

Low-dimensional quantum-well and nanoisland heterostructures formed in the InSb/AlAs system by molecular-beam epitaxy are studied by transmission electron microscopy and steady-state photoluminescence spectroscopy. The structures are grown under conditions of alternate In and Sb deposition (the socalled atomic-layer epitaxy mode) and the simultaneous deposition of materials (the traditional molecularbeam epitaxy mode). In both modes of growth, at a nominal amount of the deposited material in a single layer, large-sized (200 nm–1 μm) imperfect islands arranged on the InxAl1 – xSbyAs1–y quantum-well layer are formed. In the heterostructures grown under conditions of atomic layer epitaxy, the islands are surrounded by ring-shaped arrays of much smaller (~10 nm), coherently strained islands consisting of the InxAl1 – xSbyAs1 – y alloy as well. The composition of the alloy is defined by the intermixing of Group-V materials in the stage of InSb deposition and by the intermixing of materials because of the segregation of In and Sb atoms during overgrowth of the InSb layer by an AlAs layer.

Heteroepitaxy of AIIIBV films on vicinal Si(001) substrates

GaAs films on Si substrates miscut from the (001) plane by 6° in the [110] direction are grown by molecular beam epitaxy (MBE). GaAs films are grown both on the Si surface terminated by arsenic atoms and on thin pseudomorphic GaP/Si layers. The condition of formation of the As sublayer and the first monolayer of GaP on the Si surface is defined as the GaAs film orientation (001) or

GaAs MBE on vicinal substrates Si (001): Impact of nucleation and growth conditions on crystallographic properties of the epitaxial layers

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Molecular beam epitaxy of III-PxAs1 − x solid solutions: Mechanism of composition formation in the sublattice of a group V element

. The processes of Si surface preparation and formation of the As sublayer and GaAs and GaP epitaxial layers are monitored by means of high-energy electron diffraction reflection (RHEED). The grown structures are investigated by methods of X-ray diffraction, atomic force microscopy (ATM), high-resolution transmission electron microscopy (HRTEM), and low-temperature luminescences. It is shown that the epitaxial film orientation affects both the surface morphology and its crystalline properties. Intense photoluminescence is obtained from the In0.17Ga0.83As quantum well structure grown on the GaAs/Si buffer layer.

GaAs layers grown on silicon substrates by MBE for photovoltaic application

GaAs films were grown with molecular beam epitaxy (MBE) method on Si substrates defected from plane (001) at 6° towards [110]. The processes of epitaxial layers nucleation and growth were controlled with the RHEED method. Investigations of the crystallographic properties of the grown structures were carried out by the methods of X-ray diffractometry and transmission electron microscopy (TEM). It is shown that the cyclic annealing and the LT-GaAs layers reduce the density of threading dislocations. The orientation GaAs film and the introduction of dislocation filters have little effect on the crystallographic properties of flms of GaAs/Si (001). It was found that in the LT-GaAs/Si layer the arsenic clusters are formed, as it occurs in the LT-GaAs/GaAs system without dislocation.

The solid solutions (A III ) P x As 1−x : Mechanism of formation the V group sublattise composition

The effect of substrate temperature, As2 and P2 molecular flux densities, and growth rate on the composition of III-PxAs1 − x solid solution layers prepared by molecular beam epitaxy is experimentally investigated. Experimental data in a wide range of growth conditions are analyzed. The results obtained are presented in the form of a kinetic model for describing the process of formation of the composition in the Group V sublattice of the III-PxAs1 − x solid solution upon molecular beam epitaxy. The model can be used for choosing the growth conditions of the III-PxAs1 − x (001) solid-solution layers of a specified composition.

Molecular beam epitaxy of solid solutions GaP x As 1−x : Effect of growth condition on the composition of group V sublattice

Unijunction GaAs solar cells structures were grown on buffer GaAs/GaP/Si layers. The buffer layers were different in their crystallographic orientation ((001 or 00-1)), presence or absence of dislocation filters, also number of thermocycling operations. Solar cells without a antireflection coating were fabricated, and their characteristics were measured. Some perspective directions for improving the quality of layers GaAs/Si offered based on the experimental data and analysis of literary sources.

GaAs MBE on vicinal substrates Si(001): Impact of nucleation and growth conditions on surface morphology and crystallographic properties of the epitaxial layers

The influence of substrate temperature, density of As₂, P₂ molecules and Ga atoms flows on solid solutions AlP_xAs_1-x(001), GaP_xAs_1-x(001) and InP_xAs_1-x(001) composition at molecular-beam epitaxy (MBE) was investigated. The analysis of experimental data obtained in a wide range of growth conditions was carried out. The results of analysis are presented as a kinetic model describing the formation process of solid solution (A^III)P_xAs_1-x composition by MBE. The model can be used in the choice of growth conditions for solid solutions (A^III)P_xAs_1-x(001) layers with a set part of phosphor.

Effect of As 2 and As 4 fluxes on the morphology of GaSb(001) surface during growth of GaSb/InAs heterojunction by MBE

Impact of substrate temperature, fuxes of As₂, P₂ and Ga on the layers composition of solid solution GaP_xAs_1-x(001) during molecular-beam epitaxy (MBE) was experimentally investigated. The experimental data obtained for a wide range of growth conditions were analyzed. The analysis results are represented in the form of the kinetic model describing the formation process for composition of GaP_xAs_1-x(001) solid solution during MBE. The model can be used for the choice of growth conditions of GaP_xAs_1-x(001) at a given phosphorus fraction.