Publications on the project |
069 Patent of Ukraine for invention "Nanocomposite photocapacitor" |
Authors: | Bakhtinov A.P., Vodopianov V.M., Kovalyuk Z.D., Netiaha V.V., Konoplianko D.Y. | |
Summary: | The invention relates to nanoelectronics and capacitor manufacturing and can be used in optoelectronic memory systems, in photoelectric sensors, in light energy convertors, electric energy storages. A nanocomposite
photo-capacitor comprises a photosensitive nanocomposite material presenting as a gallium selenide semiconductor matrix of crystalline structure. It comprises arrays of crystalline structure nanosized three-dimensional (3D) potassium nitrate ferrielectrics inclusions orderly located along hexagonal symmetry axis of layered crystalline matrix. The surface density of inclusions in the basic flat (0001) of layered crystal is more then 10^9 cm-2, geometrical dimensions can not exceed single ferroelectric domain in that material. The technical result is increase of specific electric capacitance and a light overlap coefficient of solid photocapacitor within aria of low electric frequency (less than 10^2 Hz). | |
Keywords: | | |
Edition: | Bull. № 19 | | | 2012,
,Ukrainian |
069 Patent of Ukraine for invention "High-frequency spin capacitor" |
Authors: | Bakhtinov A.P., Vodopianov V.M., Kovalyuk Z.D., Netiaha V.V. | |
Summary: | The invention relates to nanoelectronics and capacitor building and can be used in modern electronics spintronic semiconductor devices where processes of transferring and accumulation of spin-polarized charge carriers are used. High-frequency spin capacitor is a vertical double barrier hybrid heterostructure based on a p-type semiconductor having a layered crystalline structure comprised orderly located nano-sized three-dimensional (3D) ferroelectric inclusions. High-frequency electric capacitance of the device is provided by transportation of spin-polarized electrons accumulated in arias of spin-selective barriers of the structure, through a system of quantum wells in nanocomposite material in strong electric fields localized in the ferroelectric inclusion areas. The technical result is increase of electric capacitance over high frequencies (over 1 MHz) and extending class of electronic devices using accumulation and transferring spin-polarized electrons at high (room) temperatures. | |
Keywords: | | |
Edition: | Bull. № 3 | | | 2014,
,Ukrainian |
069 Capacitors on the basis of intercalate <KNO₃> |
Authors: | Kovalyuk Z.D., Konoplianko D.Y., Netiaha V.V., Bakhtinov A.P. | |
Summary: | The compound GaSe<KNO₃> is obtained by the technique of intercalation of a GaSe single crystal in a melt of the ferroelectric salt KNO₃. The x-ray analysis of its crystal structure has been carried out and dielectric frequency characteristics of samples has been measured. It is established, that accumulation of electric charges occurs in the examined examples in frequency area 100-1000 Hz. A sample of filter capacitor has been created on the basis of the received compounds. | |
Keywords: | | |
Edition: | TKEA | | | 2010,
6-8,Russian |
069 Electrical and topological properties of oxides films grown thermally on InSe substrates |
Authors: | Katerynchuk V.N., Kovalyuk Z.D., Khomyak V.V. | |
Summary: | The surface resistance dynamics of oxides grown thermally on InSe substrates in two crystallography planes is obtained. It is determined that resistance changes considerably only during the first 5 minutes of the oxidization period. The increase of an oxidization duration does not influence on its value, but it results in transformation of surface topology. The images of atomic-power microscopy visualize the surface nanostructurization of oxide in the form of nanoneedles. Their lateral and vertical parameters as well as their density are caused by temperature-time factors. | |
Keywords: | | |
Edition: | TKEA | | | 2010,
6-8,Russian |
069 Electrical and optical properties of capacitors based on GaSe<KNO3> nanocomposite material |
Authors: | Kovalyuk Z.D., Netyaga V.V., Konoplyanko D.Yu., Bakhtinov A.P. | |
Summary: | Impedance spectra of the GaSe<KNO3> nanostructures are investigated under illumination. It is established that the processes of accumulation and transport of charge carriers in these structures are due to quantum-dimensional processes in high electrical fields. We have found an essential increase of the capacity of capacitors under their illumination. | |
Keywords: | intercalation, ferroelectric,capacitor,nanostructure | |
Edition: | Eastern-European Journal of Enterprise technologies | | | 2010,
30-35,Ukrainian |
069 Surface Morphology and Electrical Resistance of the Oxide Film on InSe |
Authors: | Katerynchuk V.N., Kovalyuk Z.D. | |
Summary: | Experimental evidence is presented that air oxidation of InSe crystals produces a native oxide layer which possesses not dielectric but conductive properties and is separated from the semiconductor substrate by a potential barrier. The surface resistance of oxide films grown on InSe across and along the C axis has been measured as a function of oxidation time and temperature. The results demonstrate that the surface resistance of the films varies significantly only during the first five minutes of oxidation. Subsequently, the surface resistance remains almost constant at 100–150 Ω/square. The surface morphology of the native oxide on InSe has been studied by atomic force microscopy. The oxide surface is shown to be nanotextured due to nanospikes normal to the substrate surface. The influence of oxidation temperature and time on the dynamics of the surface morphology of the oxide layer (the lateral dimensions, height, and density of nanospikes) is examined. | |
Keywords: | | |
Edition: | Inorganic Materials | | | 2011,
749-752,English |
069 Sheet resistance and surface topology time dynamics of intrinsic oxide film on InSe crystals |
Authors: | Katerynchuk V.N., Kovalyuk Z.D. | |
Summary: | It has been shown that a result of InSe crystal oxidation is formation of an intrinsic oxide film that has not insulating but conductive properties. This conductive film forms a potential barrier with the semiconductor substrate. Sheet resistance measurements of the InSe oxide film in dependence on the oxidation time under various temperature conditions were carried out. The resistance was also tested for oxide films obtained for two mutually orthogonal crystal faces: perpendicular and parallel to the с axis. It has been established that the film sheet resistance is substantially changed only for 5 min of the oxidation time, and further oxidation does not affect its value that is about 100-150 Ohm/square. Surface topology of InSe intrinsic oxide was studied using the atomic-force microscopy method. It was found that this surface becomes nanostructured and contains nanoneedles oriented perpendicularly to the plane of sample surface. Dynamics of surface topology changes in dependence on temperature-time conditions of the oxidation process has been ascertained. It manifests itself in a change of lateral and vertical dimensions of nanoneedles as well as their density. | |
Keywords: | InSe, thermal oxidation, intrinsic oxide, sheet resistance, atomic-force
microscopy, surface topology | |
Edition: | Semicond. Phys. Quantum Electron., Opoelectron | | | 2011,
106-108,English |
069 Morphology of nanostructures formed on the van der Waals surface of GaSe layered crystals annealed in sulfur vapor |
Authors: | Bakhtinov A.P., Kudrynskyi Z.R., Lytvyn O.S. | |
Summary: | The morphology of nanostructures, which were grown on the (0001) van der Waals surface of layered GaSe crystals and annealed under thermodynamically equilibrium conditions at high pressures of sulfur vapor, has been investigated using atomic force microscopy. The morphology and phase composition of the nanostructures are determined by the deformation and chemical interactions between the vapor phase and the crystal surface and by the thermodynamic conditions of annealing. Elements of nanostructures are formed as small Ga2S3 nanocrystallites, pyramidal quantum dots, and quantum rings on the defective (0001) van der Waals surface that contains nanosized indentations (nanocavities) and liquid gallium. | |
Keywords: | | |
Edition: | Fisika tverdogo tela | | | 2011,
2045-2050,Russian |
069 Synthesis and investigation of the electrical proporties of indium and gallium monoselenides intercalated by KNO3 |
Authors: | Konoplyanko D.Yu. | |
Summary: | | |
Keywords: | | |
Edition: | Scientific Bulletin of Lviv National University. Physics | | | 2011,
43-45,Ukrainian |
069 Investigation of the morphology of the van der Waals surface of the InSe single crystal |
Authors: | Dmitriev A.I., Vyshnyak V.V., Lashkarev G.V., Karbovskyi V.L., Kovalyuk Z.D., Bakhtinov A.P. | |
Summary: | The morphology of the (0001) van der Waals surfaces of the layered single crystal In1.03Se0.97, which were prepared using different techniques, has been investigated by scanning probe microscopy methods. It has been assumed that the van der Waals surface prepared with the use of an adhesive tape oxidizes in air due to the chemisorption of acid agents on dangling bonds of the metal and selenium. An analysis of the current-voltage characteristics of the tunneling current has shown that the composition of natural oxides represents a mixture of phases of the In2O3 oxide and wide-band-gap selenium oxides. In the InSe surface prepared by cleavage with subsequent exposure in air for approximately 2 min, the scanning with a tunneling microscope has revealed a surface ordering in the form of a corrugation of a complex profile with a fine structure. The last fact reflects the charge density redistribution after the chemisorption of gas molecules from air on this surface and its relaxation to the state with a minimum energy. Atoms of the basal plane are observed on the InSe(0001) van der Waals surface prepared by cleavage in an oxygen-free medium. The surface corrugation is absent. Point defects cause a disturbance of the periodic potential of the single crystal, which extends over a distance equal to four lattice spacings and appears as a shadowing. A technique has been proposed for producing In2O3 oxide nanostructures on the surface of the single crystal of the layered semiconductor InSe with the use of an atomic-force microscope probe as a nanoindenter. The ability of the probe to operate in gaseous and liquid media significantly extends the capabilities of the method. | |
Keywords: | | |
Edition: | Fisika tverdogo tela | | | 2011,
579-589,Russian |
069 Electrical properties of In2Se3 intercalated layered crystals |
Authors: | Boledzyuk V.B., Zaslonkin A.V., Kovalyuk Z.D., Pyrlya M.M | |
Summary: | The anisotropy and the electrical properties of In2Se3 layered crystals and their lithium and hydrogen intercalates are studied in the temperature range 80÷400 K. It is established that, with increase in the temperature, the electrical conduction and the mobility along layers decrease, whereas the free electron concentration remains practically invariable. The obtained temperature dependence of the electron mobility is explained by the interaction of electrons with homopolar optical phonons. A change of the electrical conduction of hydrogenated In2Se3 crystals depending on the annealing time is due to the formation of new levels in the forbidden band and the effect of intercalated hydrogen on the deformation potential of a crystal. The established decrease of the anisotropy for the Li1.5In2Se3 intercalate as compared with that of In2Se3 in the temperature interval 250÷400 К is caused by the prevailing reduction of the electrical conduction normally to layers over a slight decrease of the conduction in parallel to them. | |
Keywords: | | |
Edition: | Ukrainian Journal of Physics | | | 2011,
378-383,English |
069 Investigation of InS-InSe heterojunction prepared using sulphurisation of p-InSe |
Authors: | Kovalyuk Z.D., Duplavyy V.S., Sydor O.M. | |
Summary: | n-InS/p-InSe heterojunctions were obtained by annealing p-InSe samples in sulphur vapours. By means of the atomic force microscopy method, topology of InS film surface was investigated. Current-voltage characteristics of the heterojunction were measured, and principal mechanisms of charge transfer were established. The spectrum of relative quantum efficiency of the heterojunction was measured. | |
Keywords: | InS, InSe, heterojunction, current-voltage characteristic, annealing | |
Edition: | Semiconductor Physics, Quantum Electronics and Optoelectronics | | | 2012,
38-40,English |
069 Heterojunction formed by annealing of GaSe and InSe layered crystals in pairs of zinc |
Authors: | Kudrynskyi Z.R.,Kovalyuk Z.D. | |
Summary: | The article presents a method of creating heterojunctions based on semiconductors with different lattice types. Substrates manufactured from GaSe and InSe layered crystals were annealed in Zn vapor. This way, n-ZnSe-p-GaSe and n-ZnSe-p-InSe heterojunctions were obtained. The obtained heterojunctions are photosensitive in near and infrared spectral regions. This method opens up greate possibilities of producing heterostructures with a desired sensitivity band. | |
Keywords: | layered crystals, heterojunctions, annealing, spectral characteristics, current-voltage characteristics | |
Edition: | TKEA | | | 2012,
40-43,Russian |
069 Diffraction Properties of the Nanostructured Surface |
Authors: | Katerynchuk V.M., Kovalyuk Z.D., Savchuk A.I. | |
Summary: | The photosensitive In2O3-p-InSe heterostructures in which the In2O3 frontal layer has a nanostructured surface were investigated. The photoresponse spectra of such heterostructures are found to be essentially dependent on surface topology of the oxide. The obtained results indicate that the In2O3 oxide is not only the active component of the structure but also acts as a diffraction cellular element. The oxide surface topology was investigated by means of the atomic-force microscope technique. It was established that the surface topology is caused by the technological conditions of growing In2O3 oxides. Under different conditions of oxidation the sample surfaces had contained nanoformations preferably in the form of nanoneedles. Their location has both a disordered and ordered character. The sizes, form and density of the nanoneedles are different, too. A dimensional optical effect in the oxide was found to be due to the anisotropic light absorption in InSe. The higher deviation of incident light from its normal direction due to a nanostructured surface is the higher variation in the generation of carriers in the semiconductor is. These changes consist in the energy broadening of the heterostructure photoresponse spectrum as well in peculiarities of the excitonic line. The higher density and ordering of the nanoneedles on the oxide surface is the higher long-wave shift and more intensive excitonic peak in spectrum takes place. | |
Keywords: | | |
Edition: | Journal of Nanoscience and Nanotechnology | | | 2012,
6844(1)-6844(4),English |
069 Photoelectric properties of In2O3–InSe heterostructures with nanostructured oxide |
Authors: | Katerynchuk V.M., Kudrynskyi Z.R. | |
Summary: | The photosensitive In2O3-p-InSe heterostructures, in which the In2O3 frontal layer has a nanostructured surface, have been investigated. The photoresponse spectra of these heterostructures have been found as essentially dependent on surface topology of oxide. The obtained results indicate that In2O3 oxide is not only an active component of the structure but also acts as a diffraction cell element. Oxide surface topology was investigated using the atomic-force microscope technique. Under different conditions of InSe oxidation, the sample surfaces contained nanoformations preferably in the form of nano-islands. Their location acquired both disordered and ordered characters. A dimensional optical effect in the oxide layer was found to be due to the anisotropic light absorption in InSe. The higher deviation of incident light from its normal direction due to a nanostructured surface is, the higher variation in generation of carriers in this semiconductor is. These changes consist in the energy broadening of the heterostructure photoresponse spectrum as well as in peculiarities of the excitonic line. The higher density and ordering of the nanoneedles on the oxide surface is, the higher long-wave shift and more intense excitonic peak in spectrum takes place. | |
Keywords: | InSe, In2O3, heterostructure, photoelectric properties, atomic-force microscopy, nanostructured surface | |
Edition: | Semiconductor Physics, Quantum Electronics & Optoelectronics | | | 2012,
214-217,English |
069 Surface topology of p-InSe and n-SnS2-xSex (0 <=x<= 1) layered crystals and heterojunctions on their basis |
Authors: | Katerynchuk V.N., Kudrynskyi Z.R., Kovalyuk Z.D., | |
Summary: | The surfaces of the grown p-InSe and n-SnS2-xSex layered crystals were studied by means of atomic force microscopy. By the method of optical contact we have created p-InSe–n-SnS2-xSex heterojunctions and investigated their spectral and current-voltage characteristics.
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Keywords: | atomic force microscopy, layered crystals, heterojunctions, spectral characteristics, currentvoltage characteristics | |
Edition: | Journal of nano- and electronic physics | | | 2012,
02042(1)-02042(4),Ukrainian |
069 X-Ray Diffractometry and Raman Spectroscopy Investigation or Irradiated Layered III-VI Crystals |
Authors: | Kovalyuk Z.D., Sydor O.M., Sydor O.A., Tkachenko V.G., Maksemchuk I.N., Dubinko V.I., Ostapchuk P.M | |
Summary: | The present results of investigations of the influence of irradiation on layered n-InSe, p-InSe, and p-GaSe semiconductors. Two types of irradiation are considered: (1) the bremsstrahlung gamma-quanta with effective energy of 3MeV and the irradiation dose ranging from 0.14 to 140 kGy and (2) 12 MeV electron irradiation up to the dose ranging from 3.3 to 33 MGy. The crystal structure, lattice parameters, and atom coordination environment were investigated by means of X-ray structure analysis and Raman spectra measurements. It is shown that all samples under investigation have high structural perfection. It is shown that even the maximum dose levels of -quanta and electrons did not caused qualitative changes in the investigated spectra, which indicates that the influence of the irradiation on the subsystems of vacancies and impurities in InSe and GaSe is insignificant. Possible physical phenomena occurring in the layered crystals subjected to irradiation are described. It is suggested tentatively that the dopant atoms of Cd in p-InSe are the centers for localization of radiation-induced vacancies, whereas in the intentionally undoped crystals, the vacancies are localized in the sublattices of In or Ga. These results enable one to consider layered semiconductors as potential candidates for preparation of radiation-resistant photoconverters or detectors of high-energy particles. | |
Keywords: | layered crystal, gamma-irradiation, electron irradiation, Raman spectra, X-Ray diffraction | |
Edition: | Journal of Materials Science and Enginttring A | | | 2012,
537-543,English |
069 Influence of impurity doping and gamma-irradiation on the optical properties of layered GaSe crystals |
Authors: | Zhirko Yu.I., Skubenko N.A., Dubinko V.I., Kovalyuk Z.D., Sydor O.M. | |
Summary: | Presented in this paper are the results of electron-microscopic (SEM, EDS) and low-temperature (Т = 4.5 K) photoluminescence (PL) and absorption investigations of layered GaSe crystals, both non-doped and doped with Zn, Cd and Sn impurities taken in the concentration 0.01 wt%. The crystals were exposed to gamma-irradiation with energies 0 to 34 MeV and doses up to 1014 γ/cm2 . SEM investigations did not reveal any structural changes at the crystal surface after gamma-irradiation with the investigated doses. PL investigations enabled the discovery that doping GaSe crystals with Zn or irradiation of non-doped crystals with gamma-quanta results in decreased amounts of intrinsic defects (according to Schottky and Frenkel, respectively) in these crystals. As a consequence, an essential increase in the parameter S0 (the integrated intensity of PL) was observed with increasing doses of gamma-irradiation. In contrast, doping with Sn impurities resulted in a sharp drop in S0 that began to increase after irradiation with gamma-quanta. It has been shown that gamma-irradiation of GaSe crystals doped with Cd results in the appearance of wide bands in the PL and absorption spectra, caused by transitions of carriers between direct and indirect conduction bands and deep acceptor levels, as well as by transitions of the donor-acceptor type. The types of transitions, energies of acceptor levels (25, 70, 150, 310, 460 meV) relative to the top of valence band and the energy of the donor level (165 meV) relative to the bottom of the conduction band, as well as Huang-Rys factors and the energies of lattice phonons taking part in these transitions were determined. | |
Keywords: | GaSe, layered crystals, gamma-quantum, semiconductor sensor | |
Edition: | J. Mater. Sci. and Engineering: B | | | 2012,
91-102,English |
069 Characteristics of photodiodes with "intrinsic oxide - InSe" structure , irradiated with high-energy electrons |
Authors: | Sydor O.N., Sydor O.A., Kovalyuk Z.D., Dubinko V.I. | |
Summary: | The article describes the research of the influence of electrons with an effective energy of 12 MeV in the 0,33—33 Mrad dose range on the electrical and photovoltaic properties of photodiodes with "intrinsic oxide — p-InSe" structure. It has been found that the minimum dose improves their basic parameters, while the maximum dose significantly reduces the short circuit current and devices photosensitivity. In this case, an increase in volt-watt sensitivity and a minimal increase in coupling coefficient of the I-V characteristic are observed. | |
Keywords: | layered crystals, indium selenide, photodiode, high-energy electrons, radiation defects | |
Edition: | TKEA | | | 2012,
29-31,Russian |
069 Dimensional optical effect in the In2O3 nanostructured films |
Authors: | Katerynchuk V.N., Kudrynskyi Z.R. | |
Summary: | In the In2O3 surface-nanostructured films the dimensional
optical effect was revealed due to the investigations of the
photoelectric properties of In2O3−p-InSe heterostructures with
the anisotropic substrate. Under fabrication of such structures
the surface of intrinsic oxide is structured in an ensemble of
nanoneedles the topology of which depends on time of structures
forming. The oxide asperities peculiarities were investigated by the
atomic-force microscope images. The direct dependence between
the surface topology and the structure of the heterostructures
photoresponse spectra was established. The higher the density,
height, and ordering of nanoneedles on the oxide surface, the
more marked is the long-wavelength shift and more intensive is
an appearance of the edge peak in the photoresponse spectra. All
the spectra changes are interpreted on basis of model of interaction
of light with the nanodimensional cellular-type oxide surface which
results in strong diffraction of rays. | |
Keywords: | | |
Edition: | Fizika i technika poluprovodnikov | | | 2013,
320-323,Russian |
069 Surface topology of CdO thin oxide films formed on Van Der Waals surfaces oF InSe and GaSe layered crystals |
Authors: | Kudrynskyi Z.R | |
Summary: | Thin films of CdO were fabricated by dc reactive magnetron sputtering onto van der Waals surfaces of InSe and GaSe layered crystals. The structure of the films was studied by X-ray diffraction method. Surface topology of the obtained films was investigated by atomic force microscopy. It was established that the surface is nanostructured, but the growth of the films differs on InSe and GaSe substrates. On InSe substrate one can observe nanoobjects in the form of separate hills and their clusters. The density of such nanoobjects is ∼ 2,25⋅1010 cm–2. The peculiarity of surface topology of CdO films on GaSe is that the nanoobjects are distributed uniformly and have domelike shape. There is no tendency to formation of clusters of such nanoobjects. It was estimated that the density of these nanoobjects is ∼ 6,4⋅109 cm–2. | |
Keywords: | thin oxide films, layered crystals, surface topology, atomic force microscopy | |
Edition: | Physical surface engineering | | | 2013,
185-190,Ukrainian |
069 Fabrication and characterisation of photosensitive n-CdO-p-InSe heterojunctions |
Authors: | Kudrynskyi Z.R., Kovalyuk Z.D., Katerynchuk V.M., Khomyak V.V., Orletcky I.G., Netyaga V.V. | |
Summary: | Photosensitive n-СdO/p-InSe heterojunctions were developed and studied for the first time. The hetero- junctions were fabricated by dc reactive magnetron sputtering of CdO thin films onto the freshly cleaved p-InSe single-crystal substrates (0 0 1). Surface morphology of the obtained films was studied by means of atomic force microscopy. From the X-ray diffraction result, it is shown that the CdO film is polycrystalline with cubic structure. The mechanisms of current transport through the space-charge region under forward and back biases were estab¬lished by investigation of temperature dependences of the I-V characteristics. The main photoelectric parameters and the photosensitivity spectra were measured at room temperature. | |
Keywords: | | |
Edition: | Acta Phys. Polonica A | | | 2013,
720-723,English |
069 Tuning the bandgap of exfoliated InSe nanosheets by quantum confinement |
Authors: | Mudd G.W., Svatek S.A., Ren T.M., Patane A., Makarovsky O., Eaves L., Beton P.H., Kovalyuk Z.D., Lashkarev V.G., Kudrynskyi Z.R., Dmitriev A.I. | |
Summary: | Strong quantization effects and tuneable near-infrared photoluminescence emission are reported in mechanically exfoliated crystals of γ-rhombohedral semiconducting InSe. The optical properties of InSe nanosheets differ qualitatively from those reported recently for exfoliated transition metal dichalcogenides and indicate a crossover from a direct to an indirect band gap semiconductor when the InSe flake thickness is reduced to a few nanometers. | |
Keywords: | indium selenide, two-dimensional systems, dichalcogenides, atomic force microscopy, micro-photoluminescence | |
Edition: | Advanced Materials | | | 2013,
1714-1718,English |
069 Nanocomposite materials based on GaSe and InSe layered crystals, intercalated RbNO3 ferroelectric |
Authors: | Kudrynskyi Z.R., Netyaga V.V. | |
Summary: | In the present study, we established for the first time that single-crystal samples of gallium GaSe and indium InSe selenides can be intercalated by molecules of RbNO3 ferroelectric salt rubidium nitrate. We investigated kinetics of the intercalation process at different temperature-time regimes. Structural properties of the intercalate nanocomposites were studied by X-ray diffraction. The studied structures can be presented as composite superlattices which consist of a lattice of anisotropic layered semiconductor with embedded ferroelectric layers. We established that GaSe<RbNO3> nanocomposite material exhibits electric energy storage properties. Energy storage properties are associated with polarization of the intercalated ferroelectric under external electric field. We developed a solid state electric energy storage device on the basis of GaSe<RbNO3> nanocomposite material. | |
Keywords: | nanocomposite materials, layered crystals, ferroelectric, intercalation, gallium selenide, indium selenide | |
Edition: | Journal of nano- and electronic physics | | | 2013,
03028-03035,Ukrainian |
069 Photosensitive n-In2O3 / p-InSe heterojunctions with nanostructured surface of the frontal layer |
Authors: | Kovalyuk Z.D., Kudrynskyi Z.R., Katerynchuk V.N., Lytvyn O.S. | |
Summary: | We report on photosensitive n-In2O3 / p-InSe heterojunctions with nanostructured In2O3 frontal layer. It was established that photoresponse spectra of the heterojunctions significantly depend on the surface topology of the oxide. this means that the oxide with semiconductor substrate is not only an active component of the structure, but also serves as a cell diffraction material. Surface topology of the oxide was studied by means of the atomic force microscope. At various conditions of oxidation of InSe the surface of the samples contained nanoformations preferably in the form of nanoneedles. Their location has both a disordered and ordered character. A dimensional optical effect in the oxide was revealed due to the anisotropic light absorption in InSe. The higher deviation of incident light from its normal direction due to a nanostructured surface is, the higher variation in the generation of carriers in the semiconductor is. These changes consist in the energy broadening of the heterojunction photoresponse spectrum as well as in the peculiarities of the excitonic line. The higher density and ordering of the nanoneedles on the oxide surface is, the higher long-wave shift and more intensive excitonic peak in the spectrum takes place. | |
Keywords: | heterojunctions, layered crystals, nanostructures, atomic force microscopy, oxide films | |
Edition: | Journal of nano- and electronic physics | | | 2013,
030271-03274,Ukrainian |
069 Temperature dynamics of polarization sensitivity spectra of intrinsic oxide–p-InSe heterojunctions |
Authors: | Katerynchuk V.N., Kudrynskyi Z.R., Kovalyuk Z.D. | |
Summary: | Temperature dependence of the photopleochroism coefficient for the intrinsic oxide–p-InSe heterojunction was investigated. We observed different temperature dependence of the shift of longwave edge of photocurrent for two polarization orientations: Е||С and Е_|_С. | |
Keywords: | intrinsic oxide–p-InSe heterojunction, anisotropy, photopleochroism coefficient | |
Edition: | Sensor electronics of microsystem technologies | | | 2013,
92-96,Ukrainian |
069 Impurity band in electron-irradiated n-InSe |
Authors: | Mintyanskyi I.V, Savytskyi P.I., Kovalyuk Z.D. | |
Summary: | Electrical properties of indium selenide InSe single crystals irradiated with electrons with energy of 9,2 MeV are investigated in the temperature range 80 to 400 K. The observed extrema in the temperature dependences of the Hall coefficient and the Hall mobility of electrons along the layers are explained by considering the two-band model with electrons in both the conduction and impurity bands created by donor centers. The carried out numerical calculations taking into account a redistribution of carriers between the bands well reproduce the experimental data. An analysis of the temperature dependence of chemical potential and calculations within the model of partially compensated donor level additionally confirm the existence of the impurity band with a width of 6 to 8 meV. High mobilities of the carriers in this band are supposed to be due to delocalized conduction type.
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Keywords: | | |
Edition: | Physical surface engineering | | | 2013,
326-377,Ukrainian |
069 Optical and electrical properties of InSe and GaSe layered crystals intercalated with ethanol |
Authors: | Boledzyuk V.B., Kovalyuk Z.D., Pyrlya M.M, Barbyutsa S.G. | |
Summary: | Structural, optical, and electrical properties of InSe and GaSe single crystals diffusely intercalated with ethanol have been studied. The X-ray analysis confirmed that ethanol molecules become introduced into the interlayer space of samples. The dependences of the energy position of the main exciton maximum and a half-width of the excitonic absorption band on the holding time of InSe and GaSe single crystals in ethanol are found to be non-monotonous. The temperature dependences of the conductivity, concentration, and mobility of electrons along the layers in InSe are obtained. The change in the conductivity of InSe crystals intercalated with ethanol and its dependence on the holding time are explained by the formation of new levels in the energy gap and the influence of intercalated alcohol molecules on the deformation potential in a crystal.
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Keywords: | InSe, GaSe, intercalation
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Edition: | Ukrainian Journal of Physics | | | 2013,
859-864,Ukrainian |
069 Electrical and photoelectrical properties of anisotype n-CdO−p-InSe heterojunctions |
Authors: | Katerynchuk V.N., Kudrynskyi Z.R., Khomyak V.V., Orletskyi I.G., Netyaga V.V., | |
Summary: | Anisotype n-CdO−p-InSe heterojunctions were created for the first time on the basis of InSe layered crystals. Temperature dependences of I−V characteristics of the heterojunctions were studied. Mechanisms of charge transport through the barrier under forward and reverse bias were established. Photosensitive region of the heterojunctions was defined. | |
Keywords: | | |
Edition: | Fizika i technika poluprovodnikov | | | 2013,
935-938,Russian |
069 Optical properties of layered GaSe and InSe crystals intercalated with hydrogen containing of toluene, water and alcohol. Comparative Study. |
Authors: | Zhirko Yu.I., Skubenko N.A., Kovalyuk Z.D. | |
Summary: | GaSe, InSe, Photoluminescence, Intercalation, H2O, C7H8, C2H5OH
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Keywords: | GaSe, InSe, Photoluminescence, Intercalation, H2O, C7H8, C2H5OH
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Edition: | Materials and processes for energy: communicating current and technological developments (A. Mendez-Vilas, Ed): in Energi Book Series-№. 1 | | | 2013,
895-902,English |
069 Spectral anisotropy of a photoresponse from heterojunctions based on GaSe and InSe layered crystals |
Authors: | Katerynchuk V.N., Kudrynskyi Z.R., Kovalyuk Z.D. | |
Summary: | The object of investigation is photoresponse spectra taken from the cleaved end face of heterojunctions formed by GaSe and InSe anisotropic crystals. Spectra taken from the as-prepared and chemically processed faces of the heterojunctions are compared. A modified method of growing GaSe crystals with a virgin end face is suggested, and the surface of GaSe crystals thus grown is examined by atomic force microscopy. | |
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Edition: | Journal of Technical Physics | | | 2014,
99-102,Russian |
069 Structure of oxidized and unoxidized end faces of GaSe layered crystals |
Authors: | Katerynchuk V.N., Kudrynskyi Z.R., Kovalyuk Z.D. | |
Summary: | The surface topology and structure of unoxidized and oxidized end faces of a GaSe crystal have been studied by atomic force microscopy and X-ray diffraction. The largest deviation of the unoxidized end face of the GaSe crystal was within ≃2 nm, indicating high surface quality. The thermal oxidation of the GaSe crystal in air at a temperature of 600°C for 4 h was shown to influence the topology of its end face. Its structure resembled a set of small-angle cones with a density of ≃4 × 109 cm−2. Oxidation led to the formation of two chemical phases in the near-surface region: Ga2Se3 and Ga2O3. | |
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Edition: | Inorganic Materials | | | 2014,
339-343,English |
069 Photopleochroism coefficient and its temperature dynamics in the natural oxide-p-InSe heterojunctions |
Authors: | Katerynchuk V.N., Kudrynskyi Z.R., Kovalyuk Z.D. | |
Summary: | Temperature dependence of the photopleochroism coefficient for the natural oxide-p-InSe heterojunction was investigated. We observed different temperature dependences of the shift of photocurrent longwave edge for two polarization orientations: E || k C and E _|_ C. | |
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Edition: | Fizika i technika poluprovodnikov | | | 2014,
797-800,Russian |
069 Photosensitive anisotype n-ZnSe / p-InSe and n-ZnSe / p-GaSe heterojunctions |
Authors: | Kudrynskyi Z.R., Kovalyuk Z.D. | |
Summary: | Anisotype n-ZnSe/p-InSe and n-ZnSe/p-GaSe heterojunctions are obtained for the first time. They are grown on layered crystalline GaSe and InSe substrates by annealing in Zn vapor. It is found that these heterojunctions are sensitive to light in the near-infrared and visible spectral ranges. | |
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Edition: | Journal of Technical Physics | | | 2014,
102-105,Russian |
069 Room temperature electroluminescence from mechanically-formed van-der Waals III-VI homo-junctions and heterojunctions |
Authors: | Balakrishman N., Kudrynskyi Z.R., Fay M., Mudd G., Svatek S., Makarovsky O., Kovalyuk Z.D. Eaves L., Beton P., Patane A. | |
Summary: | Room temperature electroluminescence from semiconductor junctions is demonstrated. The junctions are fabricated by the exfoliation and direct mechanical adhesion of InSe and GaSe van der Waals layered crystals. Homojunction diodes formed from layers of p- and n-type InSe exhibit electroluminescence at energies close to the bandgap energy of InSe (Eg = 1.26 eV). In contrast, heterojunction diodes formed by combining layers of p-type GaSe and n-type InSe emit photons at lower energies, which is attributed to the generation of spatially indirect excitons and a staggered valence band lineup for the holes at the GaSe/InSe interface. These results demonstrate the technological potential of mechanically formed heterojunctions and homojunctions of direct-bandgap layered GaSe and InSe compounds with an optical response over an extended wavelength range, from the near-infrared to the visible spectrum. | |
Keywords: | metal chalcogenides, electroluminescence, van der Waals crystals, homojunctions, heterojunctions | |
Edition: | Advanced Optical Materials | | | 2014,
1064-1069,English |
The events in the framework of the project |
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069 3.1. Multifunctional nanomaterials Purpose:Finding of the features of nano-objects building on the surface of III-V layered semiconductors, creating nanostructures "layered crystal-ferroelectric" by intercalation, study of technological factors on the dynamics nanoformations. Expected results:Release of new product: technology Stage 1:Growing III-V layered semiconductors and creating nano-objects on its surface. Stage 2:Elaboration of technology for nanoformations on the surface of III-V layered crystals by its oxidation in air, by annealing in sulfur vapor and the creation of nanoscale ferroelectric phases in the van der Waals gaps. Stage 3:Investigation of structural, electrical, optical and photovoltaic properties of layered semiconductors and growing on its a new quantum-dimensional nano-objects of various thermodynamic equilibrium form. Stage 4:Making of heterojunctions based on layered crystals by using various techniques of a potential barrier formation. Stage 5:Investigation of the high radiation effect on the properties of films and heterostructures.
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