Igor Prokopenko

Igor Prokopenko
National Academy of Sciences of Ukraine | ISP · Division of Structural and Elemental Analysis of Semiconductor Materials and Systems

About

83
Publications
2,857
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243
Citations
Citations since 2016
5 Research Items
66 Citations
20162017201820192020202120220246810
20162017201820192020202120220246810
20162017201820192020202120220246810
20162017201820192020202120220246810

Publications

Publications (83)
Conference Paper
Full-text available
Practical Atomic Force Spectroscopy Assisted by Artificial Neural Networks
Article
Full-text available
Photosensitive plasmon-active structures derived from nanostructured gold films and chalcogenide glass As20Se80 have been prepared. Regular sub-wavelength reliefs are formed on the surface of As20Se80 glass due to the interaction of an amorphous chalcogenide glass film located on the metallic film nanostructures of different geometry and a localize...
Data
The paper presents a study on modeling the mechanical interaction between the tip of a scanning atomic force microscope (AFM) and surfaces of various types, which makes it possible to optimize parameters and modes for mechanical AFM nanolithography. The practical assessment of mechanical nanoprobe lithography based on the method of a direct surface...
Article
Full-text available
We have established that mass-transport processes in two types of amorphous materials, based on light-sensitive inorganic compounds like Se and As 20 Se 80 chalcogenide glasses (ChG), can be enhanced at the nanoscale in the presence of localized plasmonic fields generated by visible light in gold nanoparticles (GNPs), if the condition of surface...
Article
The paper presents a study on modeling the mechanical interaction between the tip of a scanning atomic force microscope (AFM) and surfaces of various types, which makes it possible to optimize parameters and modes for mechanical AFM nanolithography. The practical assessment of mechanical nanoprobe lithography based on the method of a direct surface...
Article
Full-text available
Transistor heterostructures with high-carrier-mobility have been studied. It is shown that, as the γ-irradiation dose Φ increases, their degradation occurs in the following sequence. (i) At Φ < 107 rad, the GaAs surface layer is damaged to a depth of 10 nm due to a >0.2-eV decrease in the diffusion energy of intrinsic defects and, probably, atmosph...
Article
The measurements of capillary forces on different diamond-like materials and carbon allotropic modifications taken using a scanning force microscope have been discussed. The amplitude-frequency characteristics of the nanorelief surfaces studied have been widely varied by plasma chemical treatments. The measurements of capillary forces have been com...
Article
The paper presents an overview and analysis of the most reliable and at the same time rather simple theoretical models describing liquid nanomeniscus geometry and forces occurring between atomic force microscope (AFM) probe and a real surface. There are experimental results in capillary bridge force rupture measured in air, and interaction forc...
Article
Demonstrated experimentally in this work was the possibility of controlled handling the nanoparticles with the size from 50 up to 250 nm on a semiconductor surface by using an atomic force microscope under conditions of acoustic excitation. It has been shown that the selective transport of particles of a certain size is possible owing to the ch...
Article
An influence of the randomly distributed defects (RDD) in the bulk crystal on value of the intensities of hkl and hkl̄ Laue-ref lections' ratio, Y = Ihkl/Ihkl̄ is revealed. It has been shown the possibility to carry out the RDD-parameters diagnostics by deviation of Y for crystal with RDD from Yperf, for perfect crystal as well as by its variation...
Article
Full-text available
The model for deformation dependence (DD) of a jumpof the integratedintensity of scattering (IIS) in the absorption K-edgeregion is developed and experimentally approbated. The nature of randomly-distributed defects (RDD) of several types is investigated, and principles of their parameters measurement and improvement are developed using radiations...
Article
The model for deformation dependence (DD) of a jump of the integrated intensity of scattering (IIS) in the absorption K-edge region is developed and experimentally approbated. The nature of randomly-distributed defects (RDD) of several types is investigated, and principles of their parameters measurement and improvement are developed using radiatio...
Article
Silicon-based nanotechnology is highly promising since it is compatible with conventional silicon integrated technique. To date silicon nanowires have been synthesized by varying experimental conditions and a wide range of electronic nanodevices have been demonstrated. A key challenge facing the device realization is the elaboration of a self-assem...
Article
The method for determination of the single-crystal defects' parameters is proposed and experimentally certified. This method is based on the joint analysis of deformation dependences (DD) of the total integrated reflective power (TIRP), which are obtained within the approximations of 'thin' and 'thick' crystals in the Laue geometry. The semi-phenom...
Article
The authors created n-InSe/p-CdTe heterojunction by deposition over optical contact, investigated temperature evolution of its current-voltage dependences under the forward bias, and determined the prevailing current transport mechanisms in the structure. It was shown that misfit dislocations at the boundary between the semiconductors form a stable...
Article
Within the scope of the dynamical theory of x-ray scattering in crystals with defects of arbitrary sizes for Laue diffraction geometry, the phenomenon model is developed for the total integrated reflective power (TIRP) dependence for 'thin' crystals, which contain defects, on the cylindrical elastic bent degree. Those parameters of this model, whic...
Article
The growth, shaping, and doping of silicon nanowires in a catalyst-mediated CVD process are analyzed within the framework of a multilevel modeling procedure. At an atomistic level, surface transport processes and adsorption are considered by MC simulations. At the macroscopic level, numerical solutions of chemical kinetics equations are used to des...
Article
To reveal recombination centers responsible for ZnO UV photosensitivity, combined investigations of photoconductivity (PC) and photoluminescence (PL) spectra were performed in nominally undoped ZnO single crystals. In PL spectra, green (500 nm), orange (620 nm) and red (720 nm) bands related to deep levels were present, the greater the relative int...
Article
We have investigated lateral self-assembling in In0.4Ga0.6As/GaAs quantum dot (QD) multilayers, which were grown by molecular beam epitaxy on GaAs(100) and (n11)B substrates with n = 9,8,7,5,4,3. The lateral self-assembling and the QD size distribution have been studied by atomic force microscopy depending on substrate orientation and the number of...
Article
Dense ensembles of silicon nanowires were prepared by metal-catalyzed chemical vapor deposition on silicon substrates. Some of these ensembles were doped with phosphorous during growth. The nanowires were characterized using scanning electron microscopy, X-ray diffraction, and mass spectroscopy. Field emission of electrons from these structures was...
Article
Peculiarities of PbTe nano-islet films formation on BaF2 (111) fresh cleavages by hot wall epitaxy deposition have been investigated using atomic force microscopy. It has been shown that various growth mechanisms could be realized by selection of proper temperature regimes in the growth chamber: growth of three-dimensional nano-islets (Volmer-Weber...
Article
The dynamic diffraction model is proposed and experimentally approved. It describes the experimental deformation dependences (DD) of the total integrated reflection power (TIRP), which are obtained within the 'thick'crystal approximation in Laue geometry, for single crystals containing the randomly distributed microdefects (RDD) within the bulk. Fo...
Article
Modified reverse micelles method allowing fabrication of CdSe nanoparticles in toluene solution in series of sizes with average diameter from 1.2 to 3.2 nm and size distribution ∼ 12-30 % is presented. Simple empirical relation between the CdSe nanoparticle diameter and exciton absorption wavelength is proposed, which allows to do prompt and effect...
Article
Surface morphology of microsize defects on the surface of various high-index GaAs substrates was investigated using an atomic force microscope (AFM). The surfaces investigated were the top layer of 1- and 17-period In0.45GaAs0.55/GaAs structures with quantum dots or buffer layer. These structures were characterized by the formation of oval defects...
Article
Correlation of the recrystallization process technological parameters with the morphology and structure of screen-printed p-CdTe layers intended for CdS/CdTe solar cell fabrication has been established. The optimal regimes to form layers with required characteristics have been found. As distinct from the used previously screen-printing techniques f...
Article
Films of nanosized composites of poly(N-epoxypropylcarbazole) (pEPC) and poly(3,6-di-Br-N-epoxypropylcarbazole) (pdBEPC) with vanadium pentoxide (V2O5) are produced for the first time ever. The electroconduction in dark and when illuminated, absorption spectra, steady-state photoluminescence spectra, and time-resolved photoluminescence spectra for...
Article
Full-text available
The methods of an X-ray diffractometry (with using quasi-forbidden reflections) probe the InxGa1-xAs/GaAs and Al xGa1-xAs/GaAs multilayered structures with quantum wells obtained by the MBE growth process. The possibility of monitoring of variations of a solid-solution composition in layers is analysed. Influence of thickness and structure on forma...
Article
We studied the effect of microwave electromagnetic radiation on silicon low-dimen- sional structures. The nanocrystalline silicon (nc-Si) films on p-Si substrate were formed with pulsed laser ablation. The surface morphology of films was studied with atomic force microscopy. We made X-ray phase analysis of films and measured strains in the structur...
Article
Phase, structural, and electrical properties of Au-Mo-TiBx-AuGe-GaAs multilayer contact systems, which are used in the process of formation of GaAs-based Gunn diodes, were investigated. The phase composition and level of residual stresses were investigated by X-ray diffraction, the morphological specific features of Au films were investigated by th...
Book
Full-text available
For a wide range of semiconductors (GaAs, GaP, InP, InSb, CdxHg1-xTe, SiC), as well as contact structures based on them, that are of importance in engineering, the monograph gives, in a systematized and generalized form, the results of investigation of their properties modification under action of high-power microwave radiations and nanosecond lase...
Article
ZnS: Cu films are prepared with a chemical nonvacuum technique by joint pyrolysis of zinc and copper dithiocarbamates at a substrate temperature between 260 and 300°C. It is shown that the films have the hexagonal lattice and are polycrystalline, with grains oriented mostly in the 〈0001〉 direction. The luminance-voltage characteristics, charge-volt...
Article
Growth of silicon nanoobjects integrated to silicon based electronic circuits is of great importance for nano-, opto-electronics as well microsensorics. In this work, self-organizing technology has been used to grow silicon wires of complex structure on silicon substrate. To characterize the wires different high-resolution instruments (Hitachi SEM...
Article
Kinetics of recrystallization in screen-printed polycrystalline CdS films has been investigated by X-ray structure analysis and optical microscopy. The relation between the crystallite size, crystallite orientation and the macrostrain, as well as their dependence on heat treatment regimes is established. It is shown that single-phase CdS films havi...
Article
Full-text available
The surfaces of wire-like silicon crystals grown by self-organization processes are characterized using electron microscopy of high resolution, scanning tunnelling microscopy, x-ray microprobe analysis, secondary-ion mass spectroscopy, and Auger electron spectroscopy. The results obtained have shown that the upper layer of each microcrystal is a na...
Article
Naturally grown silicon wire-like crystals have been studied by transmission electron microscopy of high-resolution, scanning tunneling microscopy (STM), ion and Auger spectroscopy. It is known that they are the smallest Si-based heterostructures consisting of a central core of bulk silicon and a nanoporous silicon envelope. Such a structure of the...
Article
The surface morphology of the polymer films based onpolyepoxypropylcarbazole and 3,6-di-Br-polyepoxypropylcarbazole with V 2 O 5 was investigated by Atom Force Microscopy (AFM). The surface of composite has been found to be a chaotically intertwining of V 2 O 5 fibres intermittent with inclusions of a corresponding polymer. Polymer inclusions are s...
Article
For TiBx film ~50 nm thick formed by magnetron sputtering from a pressed target onto the <100> GaAs substrate we experimentally revealed lateral nonuniformity ordering at microwave irradiation (frequency of 2.45 GHz, illuminance of 1.5 W/cm2). This correlates with improvement of the TiBx-n-n+-GaAs diode structure parameters after similar microwave...
Article
Complex of X-ray diffractometrical investigations, both angular and spectral dependences of a reflectivity for quasi-forbidden reflections, enable not only to discover structural microdefects and to measure their radii r as well as concentration n, but also to determine the level of nonstoichiometry, , where are concentrations of lattice components...
Article
Silicon and silicon-germanium wire-like crystals grown by self-organizing processes have been studied by high-resolution transmission electron microscopy, scanning tunnelling microscopy, and ion and Auger spectroscopy. It is shown for the first time that such a crystal consists of a central part of bulk material and a nanoporous envelope and that t...
Article
Full-text available
Two-dimensional maps of x-ray diffuse scattering (DS) in a reciprocal space for a real crystal containing Coulomb deformation centres (clusters or dislocation loops) were calculated using a new dynamical theory developed for a crystalline media with homogeneously distributed defects. Such maps were calculated for both the fundamental, 400, as well...
Article
The structure of two types of GaAs i-n −-n-n + epilayers on GaAs〈100〉 semi-insulating substrates was studied by electron microscopy. The low-temperature photoluminescence spectra were measured and their special features were analyzed. It is shown that the formation of dislocations during growth in such structures significantly affects the photolumi...
Article
Dynamic phenomena, namely the thickness oscillations of reflectivity and the angular variations of intensity in Laue-transmitted beams, have been shown to manifest themselves both in experiments and in numerical calculations performed by using the Takagi equations and the corresponding formulae of the theory of X-ray dynamic scattering for quasi-fo...
Article
For the first time, ZnS:Cu films with an intense photoluminescence were prepared by a chemical nonvacuum method. They were produced by means of the combined pyrolytic deposition of zinc and copper dithiocarbamates onto glass and ceramic substrates heated up to 260–300°C. A close packing of practically identical grains is characteristic of these fil...
Article
The investigations of the structure parameters of Au–TiB2/GaAs and TiB2/GaAs device structures and their transformations at short-term thermal annealing were carried out. The metal films were magnetron sputtered on Czochralski-grown (001) GaAs in an argon atmosphere. The growth rate was ∼5 nm/s and the film thickness ranged from 10 to 50 nm. The sa...
Article
We present the results of structural, analytical, optical and electrophysical investigations of TiBx–GaAs contacts. They were obtained by magnetron sputtering from pressed powder targets and were studied before and after rapid (60 s) thermal annealing (RTA) in a hydrogen atmosphere at T=400°C, 600°C and 800°C. It was shown that a transition layer i...
Article
Full-text available
We used X-ray diffraction method of total rocking curves and nondestructive direct observation techniques (atomic force and scanning electron microscopies) to quantitatively determine the defect characteristics (radii and concentrations) for the main types of defects in Czochralski-grown silicon single crystals annealed at 750 °С.
Article
Full-text available
One of the important subjects in the material science of semiconductor compounds is a problem of stoichiometry. The methods based on the measurement of kinematical integral reflectivity (IR), RiK, for the quasi-forbidden reflection (QFR) of X-rays were formerly used for investigation of the GaAs composition. To determine the value of deviation from...
Article
Full-text available
The topology of the pendulum fringes of intensity in the Borrmann triangle in the Bragg case of diffraction in a crystal with planar defects is investigated by the numerical solving of the Takagi-Taupin equations. The peculiarities of X-ray diffraction on the defect boundaries for the cases of a thin layer and a thick one with plane surfaces as wel...
Conference Paper
Si/Si and Ge<sub>x</sub>Si<sub>1-x</sub>/Si superlattices were grown by vapour-transport reactions. Au and Pt were used to initiate self-organized growth of different “brushes”. A low of distribution and shape of growth peculiarities has been studied by electron microscopy
Article
The polycrystalline SmS films were fabricated by MOCVD technique using a number of ditiocarbamates, synthesized by different techniques. The growth kinetics and temperature dependen-cies of the film growth rate are investigated, which allowed us to determine the activation energies and the reaction type. The investigations of the structure and surf...
Article
The averaged values of radii r̄ and concentration n̄ of microdefects which are the SiOx precipitates surrounded by dislocation loops were determined from the measured X-ray integral reflectivities of Czochralski grown silicon crystals subjected to annealing at high hydrostatic pressure (107–109 Pa) as well as from analysis of differential diffuse s...
Article
Full-text available
The research of the surface and the near-surface region of Cz-Si wafers irradiated with fast oxygen and neon ions of energy 4 MeV/u and dose 1014 particles/cm2 is presented. In our study several methods based on the Bragg case of X-ray diffraction using Ag Kα1, as well as reflection high-energy electron diffraction and Nomarsky optical microscopy w...
Article
Full-text available
Manifestation of the dynamical phenomena, namely the thickness oscillation of a reflectivity, the angular variations of an intensity in the Laue-transmitted beams, was shown experimentally as well by calculations using the Takagi equations and the corresponding formulae of the theory of X-ray dynamical scattering for the quasi-forbidden reflections...
Conference Paper
The effect of ultrasonic treatment on the physico-chemical, structural, and electrical properties of Pt,Cr,W/n-n<sup>+</sup>-GaAs structures has been studied. It is shown that ultrasonic treatment produces spatial and chemical ordering of the contact region of GaAs. This decreases the reverse currents in diode structures with a Schottky barrier. A...
Article
Full-text available
The proposed new method of the differential-integral triple-crystal X-ray diffractometry of imperfect single crystals is justified theoretically and experimentally. The principles of the work of triple-crystal diffractometer (TCD) in the differential mode of measurements are described. Original construction and scheme of the universal TCD created i...
Book
In recent years considerable attention of numerous researchers has been focused on the effect of different radiations on semiconductor materials and devices. This is especially true in regard to the GaAs-based integrated circuits (IC) and devices. It is these devices that are most widely used in the areas of high radiation levels (such as atomic po...
Article
Processes of the structure relaxation in GaAs single crystals under microwave electromagnetic radiation depending on duration of processing are investigated. The magnetron radiation with frequency 2.38 GHz and irradiancy 100 W/cm2 is used. It is shown by X-ray diffraction techniques that the change of structural characteristics such as residual str...
Conference Paper
The transport phenomena and mechanical strength of monocrystalline Si and Ge were investigated at extremely high uniaxial stress. The low temperature plasticity was studied by the conductivity recording and the metallographic method. It was established that the real mechanical strength of Si and Ge crystals was substantially lower than a theoretica...
Article
The effect of ultrasonic treatment on the physicochemical, structural, and electrical properties of Pt, Cr, W/n-n +-GaAs structures has been studied. It is shown that the ultrasonic treatment produces spatial and chemical ordering of the contact GaAs region. This decreases the reverse currents in diode structures with a Schottky barrier. A possible...