2001   Volume 2   №3

Summary

Y.A. Mazurenko, A.I. Gerasimchuk, V.P. Ovsiannikov

Chemical Vapour Deposition, Synthesis of Functional Materials (review)

Institute of general and inorganic chemistry NAS Ukraine, 32/34, Palladine Av., Kyiv-142, 03680

The fundamental method aspects of chemical vapor deposition  (CVD) are considered. Development of this method, for last time gave rise to development of various its modifications essentially distinguishing it from classic variant. Into intercourse with those offers a generalized CVD processes scheme, that leagues all of these methods. Considered theoretical choice bases and synthesis precursors for CVD processes managing principle properties of functional materials, derivable by CVD method. Seen out method variants examination, their practical application and development perspective.

V.F. Zinchenko¹, N.P. Efryushina¹, G.I. Kocherba¹, O.G. Eryomin¹,
V.P. Sobol², O.V. Mozkova², V.Ya. Markiv³, N.M. Bilyavina³

Optical and Operational Properties of Thin-Film Coatings Obtained by the Vacuum Evaporation of RE Fluorides

¹O.V.Bogatskiy Physics-Chemical Institute NAS Ukraine,
86, Lyustdorfska Str., Odessa, 65080, E-mail: physchem@paco.net
²CCB "Arsenal", 8, Moskovska Str., Kyiv, 01010, tel. 044-254-59-08, E-mail: pagor@ukrpost.net
³Taras Shevchenko Nayional University, 60, Volodymyrska Str., Kyiv, 01003, E-mail: belmar@mail.kiev.ua

The regular research of binary and complex Rare Earths (RE) fluorides such as LnF₃ (Ln = La÷Lu, Y, Sc) and LnF₃-Ln'F₃, LnF₃-Ln'F₃-MFx (M-s, d-metal) as prospective materials for creation of coatings with a low refractive index is carried out. The materials are synthesised by a method of sedimentation by H₂F₂ from water solutions with the following fluoridation and thermal treating. X-ray method, chemical analysis and diffuse reflection spectroscopy identify the materials. The thin-film coatings are put by methods of thermal vacuum evaporation on substrates from different materials. The refractive index of coatings lays in borders 1,44÷1,61 while factor of dispersion essentially changes depending on a nature RE being 2,2–2,5 % for ScF₃ up to 0,03–0,12 % for EuF₃. The crystal structure of fluorides in coatings essentially does not change in comparison with initial FFM, with exception of EuF₃. The possible reasons of change of the composition and structure of EuF₃ during evaporation are discussed. The optical and operational properties of coatings on a basis of RE fluorides (particularly YbF₃) are essentially improved under action of the admixtures of other metals fluorides.

Ya.S. Budjak¹, D.M. Freik², L.I. Nykyruy², L.Y. Mezhylovska²

Elements of the Theory to Crystals Kinetic Properties for the Solid State

¹State University “Lvivska Polytehnika”, 12, Bandera Str., 79005, Lviv
²Physics-Chemical Institute at the Vasyl Stefanyk Precarpathian University,
 57, Shevchenko Str., 76000, Ivano-Frankivsk

Influence of symmetry elements of variance low on kinetic properties anizotropic crystals are shown.

A. Popescu², A. Buzdugan¹, V. Dolghier³

Modeling of the As₂(S, Se)₃Sn_0.1 Planar Waveguides Before and After Illumination

¹Center of Metrology, Automation & Scientific Research Work;
²Center of Optoelectronics, Institute of Applied Physics, Moldova;
³International Laboratory of High Temperature Superconductivity and Solid State Electronics, 3/2,
Academiei Str., MD-2028, Chisinau, Moldova

Is studied the influence of the illumination to characteristics of the structure of the thin films of As₂S₃ and As₂Se₃ doped with 2% of tin. As a result of photostructural transformation under illumination the tin atoms change their valence from IV to II. In a like manner the illumination changes the coordination number of the tin atoms and that make the structure of the doped thin films more stable.

A.B. Glot, A.M. Makeev

Non-Linear Electrical Characteristics of Composite Layers Conductor-Dielectric

Dnipropetrovsk National University,
tel.: (0562) 523581, (056) 7765426, E-mail: alexglot@mail.ru, ya_alexey@mail.ru

A current limiting phenomenon has been observed in a composite material graphite-polyethylene and was accompanied by the peak of current on the current-voltage characteristic. From the investigation of current on time and current on temperature relations one can see thermal nature of the phenomenon. Possible explanation of the effect is a destruction of some parallel conductive paths because of joule heating of them and, consequently, thermal bulk expansion of polyethylene. A simple quantitative model confirms the presence of current peak on voltage-current characteristic.

N.K. Kramar², V.M. Kramar¹, B.M. Nitsovych¹

Calculations of Effective Masses of the Electrons and Holes in the Layer Semiconductor Crystal PbI₂

¹Chernivtsi National University, 2 Kotsyubinskogo Str., 58012, Chernivtsi, Ukraine
²Bukovinian State Institute of Economics and Finanses,1 Shterna Str.,58001, Chernivtsi, Ukraine

The structure of the electrons energy bands in the layer semiconductor crystal PbI2 (2H-polytype) are calculated using the pseudopotential method. A calculation has been performed by use norm- conserving nonsocial “ab initio” pseudopotential by Bachelet-Hamann-Schlüter. Effects of the screening and correlation are taken into account. Effective masses of the electrons and holes were computed on the grounds of energies dispersion law. The presence of essential anisotropy of the electrons effective masses has been found, what is agreed with an experimental data.

B.К. Ostafiychuk¹, І.М. Gasyuk¹, О.V. Kopaev¹, V.М. Nadutov², L.S. Yablon¹

Influence of Neglegable Cationic Substitutions on
Magnesium - Zinc Ferrites Magnetic Microstructure

¹Vasyl Stefanyk Precarpathian University,
Shevchenko Str., 57, Ivano-Frankivsk, 76000, Ukraine,
²Kurdyumov metall-physics Institute NAS Ukraine,
Av. Acad. Vernadskiy, 36, Kyiv, Ukraine

On the basis of given of thermomagnetic measurements  and mossbauer spectroscopy the model of magnetic microstructure of magnesium-zinc ferrite is constructed. The influence  of cation replacements with character of the located magnetic condition is shown. At stoichiometric structure of ferrite the located magnetic condition are identical among themselves, and the ferrite is by homogeneous magnetic system.

N.T. Gladkikh, V.I. Larin, O.P. Kryshtal

About Size Dependence of Nanoparticles Surface Energy

V.N. Karazin Kharkiv National University, Physics Dep., Svobody Squ., 4, Kharkiv,
E-mail: Vitaliy.I.Larin@univer.kharkov.ua, tel. 0572-457589

The analysis of experimental outcomes on study of surface properties of nanosized metal particles has been carried out. It has been shown that examination of evaporation kinetics of small particles in vacuum and measurement of their lattice parameter allows one not only to receive information about their surface energy, but also to spot parameters describing properties of a surface of such objects. We present results of the analysis of experimental outcomes on a size effect of wetting and show that these examinations allows us to receive information on a microparticle - substrate interphase energy.

V.R. Kopach, N.P. Klochko, G.I. Kopach, V.O. Novikov

Current Versus Voltage Characteristics of
Electrodeposited CIS Films

National Technical University “Kharkіv Polytechnic Institute”, 21, Frunze Str. 61002 Kharkіv, Ukraine
Fax: 00-38-0572-400-601, E-mail: kopach@kpi.kharkov.ua

The purpose of carried out researches consisted in the determination of the preparation conditions for creation of thin film p-n junction on the base of electrodeposited copper indium diselenide (CIS) that possesses I-V characteristic similar to I-V characteristic of Shockley diode.

The influences of electrodeposition and following annealing conditions on the film I-V characteristics and types of the film conductivity were investigated by means of both characterioscope technique and hot-probe method. CIS film structure and chemical composition were studied by means of SEM, XRD, EDX as well as by laser mass-spectrometry method.

The comparison of preparation conditions influence on electrical properties, structure and chemical composition of investigated CIS films has shown, that cathode electrodeposition under potentiodynamic regime from aqueous acidic chloride electrolyte contained 0.9 mM CuCl, 4.5 mM InCl₃ and 1.5 mM SeO₂ (pH 1) at cathode potential ramped from -0.50 V up
to - 0.85 V (vs. saturated Ag/AgCl reference electrode) at rate 0.5 mV/s allows to obtain approximately 1 mm thick CIS films, in which p-CuInSe₂ / n-CuIn₃Se₅ junctions with I-V characteristics similar to Shockley diode I-V characteristic were arisen after CIS films annealing in an argon at 400^oC during 1 hour.

I.N. Smolensky, N.E. Kotjuschko

Synthesis of the 1,2 - Epoksypropylderived Oxyethylmetacrylat Gel by

Means of Macroporos Spherons Epoksyding

Ivano-Frankivsk State Technical Oil and Gas University, 15,
Karpatska Str., Ivano-Frankivsk-19, 76019, Ukraine,  E-mail: ismolensky@ifdtung.if.ua

Aiming at the creation of multifunctional carries with the spacer function of biologically active substances and semiproducts of the sorbents synthesis for the liquid chromatography and chromatofocusing the thermocathalyst reaction of the gel spherons epoksiding by epichlorhydrin in the presence of alcloide metals was studied. Special methods of epoksyspherons with cynetically concentrated volume of 0.2¸1.3 mg-eqv./Gsorb. production were also developed.

M.О. Galuschak², A.D. Freik¹, L.R. Pavlyuk², V.V. Prokopiv¹, V.M. Boychuk¹

Defect Subsystem of Thallium Doped Lead Selenide

¹Vasyl Stefanyk Prekarpathian University,
57, Shevchenko Str., Ivano-Frankivsk, 76000, Ukraine, E-mail: prk@pu.if.ua
²Ivano-Frankivsk State University of the oil and gas,
15, Karpatska Str., Ivano-Frankivsk, 76000, Ukraine

Is lead crystallo-quazychemistry calculation of an equilibrium concentration of defects in electronic crystals PbSe, doped by thallium. On the basis of comparison of experimental and theoretical results, and also datas of the thermodynamic approaches, is spotted equilibrium constants quazychemistry of responses of formation of vacancies of a seleniumand interlattice of thallium

S.А. Nedilko, І.V. Golubeva, А.L. Moroz, О.G. Zenjkovych, L.Ph. Nedilko

Influence of Substitution of Different Types to Superconducted Properties
Pb-1212 Cupratus

Taras Shevchenko Kyiv National University, Chemistry Dep.,
64, Volodymyrska Str., Kyiv, 01033, Ukraine, nedilko@nsa.chem.univ.kiev.ua

Ceramic and single crystals of Pb-1212 phase of compositions: Pb_0,73Cu_0,27Sr_2‑xY_0,79Ca_0,21+xCu₂O_z and Pb_0,73Cu_0,27Sr_2‑yCd_yY_0,79Ca_0,21Cu₂O_z (0 Јx, y Ј0,5); Pb_0,7Cu_0,3Sr₂Y_1-xCa(Na)_xCu₂O_y (0,1Јx Ј 0,5) and Pb_0,7Cu_0,3Sr₂Y_1-xCu₂O_y (0 Јx Ј0,3); Pb_1-xA_xSr₂Y_0,55Ca_0,45Cu₂O₇ (A = Cd, Ag, Zn, In: 0 Ј x Ј 0,5) were synthesized. Polycrystalline materials were obtained by precursor method and single crystals were grown by self-flax crystallization method. Materials obtained were studied by XRD technique, electron dispersion analysis, magnetic susceptibility and electroconductivity measurements. Correlations between superconducting properties and the nature of constituent cations were determined.

B.T. Boyko, G.S. Khrypunov, O.P. Chernykh

The Investigation of External and Internal Parameters of the
Thin Film Solar Cells Based on CuGaSe₂

National Technical University «Kharkiv  Polytechnical Institute»,
 Frunze, Str. 21, Kharkiv, 61002

By computer processing of the experimental light voltage-ampere characteristics the research output and diode parameters of thin film solar cells on the base of CuGaSe₂ was carried out. It was shown that reduction of the diode current saturation density and of series resistance and increasing of shunting resistance determinate the increasing of efficiency of solar cells with increasing of substrate temperature. The researches of spectral dependencies a of quantum efficiency factor have shown, that limitation of ZnO:Al/i-ZnO/CdS/CuGaSe₂/Mo solar cell efficiency at a level 6,4% on a comparison with ZnO:Al/i-ZnO/CdS/CuIn_0.71Ga_0.29Se₂/Mo solar cell with efficiency 12,3% is determined by a more intensive surface and volume recombination of non-equilibrium carriers generated by light.

Yu.G. Dobrovolskiy¹, А.А. Ascheulov²

Features of a Construction and Technology Silicon p-i-n Photodiodes

¹“CCB Rytm”, Golovna Str., 246, Chernivtsi, 58032, tel. (03722) 4-26-13, 7-87-21, E-mail: yuriydr@west.com.ua
²Yuriy Fedjkovych Chernivtsi National University,
2, Kotsyubynskiy Str., Chernivtsy, 58012, tel. (0572) 53-06-27

In the paper the basic approaches to designing and manufacturing modern silicon p-i-n of photodiodes are submitted. The mechanisms are considered which influence on dark a current of photodiodes and the review of ways of reduction generation by a component dark of a current is made. The results of influence on crystals p-i-n of photo diodes of static electrical and magnetic fields of the certain geometry are given which are capable to increase time of life of the not basic carriers of a charge in these crystals.

М.І. Dovgoshey, N.І. Popovych, І.Е. Kacher

Mass-Spectrometer Examinations of Processes of Thermal and Laser Transpiration of ZnGa₂S₄ Crystals

SRI PCSS at the Uzhgorod National University,
Pidgirna Str., 46, Uzhgorod, 88000, Е-mail: pmm@univ.uzhgorod.ua

In the article reduced results of mass-spectrometer examination of processes thermal and laser transpiration of stiogallat zinc crystals ZnGa2S4. Is obtained, that the sublimation of a composition ZnGa₂S₄ begins at temperature 1030 К; the most intensive transpiration is observed at temperature, higher for 1250 К. Reaction heat of transpiration of a composition ZnGa₂S₄ is 138.2 kkal/mol. In mass spectrums of resultant of laser erosion are detected both one-charging ions all a builder of a composition, and polyatomic clusters of binary and triple builders of a pair.

R.Ya. Mykhailyonka, V.M. Klanichka, G.D. Mateik

Thermoelectrical  Properties  Both  of  Lead Telluride-Gadoliniy  Telluride,
and  Lead  Telluride-Therbiy  Telluride  Solid  Solution

Physics-Chemical Institute at the Vasyl Stefanyk Prekarpathian University
57, Shevchenko Str., Ivano-Frankivsk, 76000, Ukraine

The dependence of specific electrical conductivity (s), efficient thermal electromotive force (a), and specific thermal capacity from composition of both solid solution PbTe-Gd₂Te₃ and PbTe-Tb₂Te₃ is investigated. The composition with optimal value of thermoelectric parameters is determined. Is propose the crystall-quasychemistry describe of defects subsystem of the bases matrix of solid solution.

D.L. Kardashev

Influence of the Isolated Impurity of Hydrogen on Density of Electronic States
of Amorphous Semiconductor Si and Ge Films

Odessa Sea State Academy, 8, Didriksona Str., Odessa, 65029, Ukraine

The electron local densities of states for isolated mono-hydride in hydrogenated amorphous Si and Ge are calculated by the Green function technique using the one-electron tight binding Hamiltonian including all nearest-neighbour interactions. The structures of the hydrogenated amorphous solids are approximated by the Bethe lattice.

S.V. Kozytsky, O.A. Rimashevsky, T.Yi. Ches’ka

Electrical Property of ZnS, Obtained by S H S Method

¹Odessa Sea State Academy, 8, Didrikhsona Str., Odessa, 65029, Ukraine
²I. Mechnikov National University, 2, Dvoryanska Str., Odessa, 65000, Ukraine

Dielectric constant and conductivity of the polycrystalline samples of ZnS obtained by method of Self-Propagation High-Temperature Syntes (SHS) was investigated with the frequency . Value of  was not anyzotropy and depended on the density of the samples. These results were explained in the frame of model where spherical pores of air were included into the crystalline material. Conductivity of samples was satisfied of Ostin-Mott’s law: with the same index =0.66.  Its indicated that we had substantial disorder in SHS-ZnS due to appearance of barriers as the result of deflection of stehіomerty and a lot of oxygen into polycrystalls.

T.M. Melnichenko, V.I. Fedelesh, I.M. Jurkin, T.D. Melnichenko, V.M. Rizak

Internal Pressure, Microhardness and Fluidity Limit
in the Chalcogenide Glasses

Uzhgorod National University, 54, Voloshin Str., Uzhgorod, 88015, E-mail : ipk@univ.Uzhgorod.ua

Through the data of elastic constants maximal internal pressure p_im is calculated for chalcogenide glasses and fluidity limit s_п . It was shown, that value of p_im not correlates with microhardness H after Vikkers in all of glasses. Fluidity (plastic) limit s_п more little then microhardness and maximal internal pressure p_im. Elastic constants and fluctuation free volume parameters in observed glasses largely depend on mean coordination number Z_ср

P.М. Fochuk, О.О. Korovyanko, О.Е. Panchuk

Calculation of Introduction Constants of the Alloying Elements in CdTe

Chernivtsy National University, chemistry dep.,  2, Kotsyubynskiy Str.,Chernivtsi, Ukraine

A short review of existing CdTe point defect structure models is proposed. Hall effect measurements at high temperature equilibrium under well-defined Cd/Te pressure, optimization of defect constants and In incorporation constant calculation were carried out. The criteria of optimization were charge carrier concentration defined from different dependencies. The average value for the In incorporation constant (973-1173 К) is K_In=5.6´0³⁹exp(-0,72 еВ/kT). The optimized CdTe defect structure models built in the framework of Kreger’s quasichemical reaction theory illustrate good agreement between experimental and calculated dependencies both for undoped and In doped CdTe.

A.A. Рtashchenko, O.S. Artemenko, F.A. Ptashchenko

Effect of Gas Atmosphere on the Surface Current in p–n Heterostructures on GaAs–AlGaAs

¹Odessa National University, 2, Dvoryanska Str., 65100, Odessa
²Odessa Sea State Academy, 8, Didrikhson Str., 65029, Odessa

The effect of vapours of water, ethylene, acetone and ammonia on I-V characteristics of the forward current of AlGaAs–GaAs double heterostructures (DHS) was investigated. The vapours of water, ethylene, and acetone did not remarkably change the surface current in DHS, while the ammonia vapours substantially increased it. The excess current caused by adsorption of NH₃ molecules linearly depends on the voltage, which can be explained by forming of a conductive surface channel in the p-n junction. The kinetics of the surface current at changing gas atmosphere was studied. The rise-time of the current after placing DHS in the NH₃ atmosphere ranged from 20 to 60s, while the decay time after subsequently replacing DHS in ear was 2 – 60 s. It is established that the surface current linearly depends on the NH₃ partial pressure in the range of 10² – 10⁴ Pа, which can be utilized for creating a sensor of this vapours.

О.Ya. Dovgiy, І.V. Kalytchuk

Conduction Profile at the PbS Epitaxial Films

Physics-Chemical Institute at the Vasyl Stefanyk Prekarpathian University
57, Shevchenko Str., Ivano-Frankivsk, 76000, Ukraine

It is made mark of the conduction profile both p- and n-type PbS films by Petriz model.

I.F. Mironyuk¹, V.V. Lobanov¹, B.K. Ostafiychuk², I.I. Grigorchak³, R.V. Ilnytskyy²

Electronic Structure and Properties of Titania Intercalated with Metalic Lithium

1Istitute of Surface Chemistry NAS of Ukraine, 17, General Naumov Str., 03164, Kyiv, Ukraine
2Precarpathian University named after V.Stefanyk, 57, Shevchenko Str., Ivano-Frankivsk, 76025, Ukraine
3Institute of Material Problems NAS of Ukraine, Lviv Department, 1, Paton Str., Lviv, 79000, Ukraine.

The electronic structure of the clusters simulating the state rutile and anatase intercalated with lithium atoms has been examined within the frameworks of SCF MO LCAO NDDO valence approximation. Basing on the examination of local density states, a conclusion has been made on the unchanged structure of rutile and anatase energy zones under embedding small quantities of lithium atoms into them.

I.M. Ivanyshyn, L.Y. Mezhylovska, V.V. Boryk

Defects in Nonstoichiometric Tin Telluride at Tetra- and Octahedral Situations of Indium

Physics-Chemical Institute at the Vasyl Stefanyk Prekarpathian University
57, Shevchenko Str., Ivano-Frankivsk, 76000, Ukraine

The relation of a defects formation of the solid solution SnTe-In versus a dose of dopant impurity is investigated. The crystalloquasichemical mechanism of solid solutions formation is proposed. Correlation between the hole concentration, number of point defects in the compounds and nature of defect formation processes was found. The concentration dependences of charge carriers and point defects are constructed

S.S. Lisniak, A.V. Bitneva, V.O. Kotsubunskiy, I.P. Yaremiy, G.V. Muhin

Crystaloquasichemical Mechanism of Adsorbtion From the Solutions and Gas on the Surface of Solid Like Spinel and Garnet

Vasyl Stefanyk Precarpation University,
57 Shevchenko Str, Ivano-Frankivsk, Ukraine

In the article the crystaloquasichemical mechanism of adsorbtion from the solutions and gas on the surface of solid like spinel and garnet has been studied. The theoretical model of surfaced active centres of adsorbtion and their dependent from charge state of cation has been proposed.