Engineering topics

Gutakovskii, A. K.

Publications and source records attributed to Gutakovskii, A. K..

4 records

DOE OSTI2019

GaAs/GaP Quantum-Well Heterostructures Grown on Si Substrates

Molecular-beam epitaxy is used to produce GaP/Si hybrid substrates that allow the growth of highly efficient light-emitting heterostructures with GaAs/GaP quantum wells. Despite the relatively high concentration of nonradiative-recombination centers in GaP/Si layers, GaAs/GaP quantum-well heterostructures grown on GaP/Si hybrid substrates are highly competitive in terms of efficiency and temperature stability of luminescence to similar heterostructures grown on lattice-matched GaP substrates.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2018

Spinodal Decomposition in InSb/AlAs Heterostructures

The atomic structure and energy spectrum of heterostructures formed in a system of InAs/AlAs binary compounds are studied. The In{sub x}Al{sub 1–x}Sb{sub y}As{sub 1–y} alloy, from which quantum wells are formed in InSb/AlAs structures, decomposes into two phases with different compositions. The characteristic dimensions of regions containing separate phases of the alloy in the structure plane are 5–7 nm. Spinodal decomposition of the alloy brings about the formation of coexisting indirect-gap regions with type-I and type-II energy spectra in quantum wells of the heterostructures.

36 MATERIALS SCIENCE↗

DOE OSTI2017

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 In{sub x}Al{sub 1–} {sub x}Sb{sub y}As{sub 1–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 In{sub x}Al{sub 1–} {sub x}Sb{sub y}As{sub 1–} {sub 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.

36 MATERIALS SCIENCE↗

DOE OSTI2016

Strained multilayer structures with pseudomorphic GeSiSn layers

The temperature and composition dependences of the critical thickness of the 2D–3D transition for a GeSiSn film on Si(100) have been studied. The regularities of the formation of multilayer structures with pseudomorphic GeSiSn layers directly on a Si substrate, without relaxed buffer layers, were investigated for the first time. The possibility of forming multilayer structures based on pseudomorphic GeSiSn layers has been shown and the lattice parameters have been determined using transmission electron microscopy. The grown structures demonstrate photoluminescence for Sn contents from 3.5 to 5% in GeSiSn layers.

36 MATERIALS SCIENCE↗