Приведены результаты теоретических и экспериментальных исследований по вопросам оптоэлектроники, солнечной энергетики и полупроводникового материаловедения фотопроводящих материалов. Изучены влияние ионизирующего облучения на электронно-ионные процессы в щелочно-галоидных кристаллах при воздействии стационарных пространственно-периодических световых полей, облучения и термоциклирования на параметры оптических полупроводниковых элементов. Освещены результаты исследования релаксации заряда в тонких пленках сульфида свинца с различным потенциальным рельефом зон. Предложена новая схема метода селективной фотодиссоциации молекул в задачах лазерной очистки полупроводниковых материалов и вещества в газовой фазе. Рассмотрены перспективные направления развития фотоэлектроники.

Головний редактор:

Наведено результати теоретичних та експериментальних досліджень з питань оптоелектроніки, сонячної енергетики і напівпровідникового матеріалознавства фотопровідних матеріалів. Визначено перспективні напрямки розвитку фотоелектроніки.

Приведены результаты теоретических и экспериментальных исследований по вопросам оптоэлектроники, солнечной энергетики и полупроводникового материаловедения фотопроводящих материалов. Определены перспективные направления развития фотоэлектроники.

Головний редактор:

Наведено результати теоретичних і експериментальних досліджень з питань оптоелектроніки, сонячної енергетики і напівпровідникового матеріалознавства фотопровідних матеріалів. Розглянуто питання застосування фотоакустичних методів для візуалізації просторового розподілу полів механічних напруг в кристалах карбіду кремнію. Проаналізовано вплив інтенсивності освітлення на кінетичні ефекти в монокристалах антимоніду кадмію. Викладено послідовні квантові підходи у теорії напівпровідникового суператома та кварконію у зовнішньому електромагнітному полі, а також до опису нових лазерних електрон-ядерних фотоявищ у молекулах. Висвітлено нову технологію обробки даних часової та просторової структур поля аерозольного забруднення і фрактальних параметрів для аерозольної атмосфери. Наведено оптимальні схеми лазерного фотоіонізаційного методу для приготування плівок надчистого складу.

Приведены результаты теоретических и экспериментальных исследований по вопросам оптоэлектроники, солнечной энергетики и полупроводникового материаловедения фотопроводимых материалов. Рассмотрены вопросы применения фотоакустических методов для визуализации пространственного распределения полей механических напряжений в кристаллах карбида кремния. Проанализировано влияние интенсивности освещения на кинетические эффекты в монокристаллах антимонида кадмия. Изложены последовательные квантовые подходы в теории полупроводникового суператома и кваркония во внешнем электромагнитном поле, а также к описанию новых лазерных электрон-ядерных фотоявлений в молекулах. Освещена новая технология обработки данных временной и пространственной структур поля аэрозольного загрязнения и фрактальных параметров для аэрозольной атмосферы. Представлены оптимальные схемы лазерного фотоионизационного метода для приготовления пленок сверхчистого состава.

Головний редактор:

Universal thermoregulating cryostat system: Вып. 13, 2004

The universal thermoregulating cryosystem ensuring a possibility to work practically with any kind of working cryoagent without a modification in construction of the cryostat is developed. For a want of application of liquid helium as the work cryoagent the system ensures regulation of temperature in a range 1,4 - 4,2 - 300 K with the stability not worse 0,1 K and the consumption of liquid helium not more 0,08 Ltr/hour. In a case of use of liquid nitrogen the system ensures a thermal control in a range 77; 80 - 300 K with the stability not worse 0,1 K and the consumption of liquid nitrogen not more 0,15 Ltr/hour.

Thermodynamical analysis of intrinsic defects in gallium nitride: Вып. 13, 2004

Thermodynamic analysis in content of intrinsic defects for GaN was carried out. The causes depending the tendency of GaN to monopolar conductivity type were observed. The model for defect formation is suggested.

The atomic chemical environment and beta electron final state interaction effect on beta decay probabilities: Вып. 14, 2005

Contributions of the atomic chemical environment effect and final states interaction of the beta electrons into the <$E beta> decay characteristics are calculated within a new theoretical, optimized gauge invariant Dirac - Fock approach. The results are presented for the non-unique transition of the first forbidding (<$E roman {nothing sup 241 Pu~symbol О~nothing sup 241 Am}>) and the super allowed transitions <$E roman {O sup +~symbol О~O sup +}>.

Surface modification of gallium phosphide stimulated by high-power pulsed laser irradiation: Вып. 13, 2004

The growth condition effect of gallium phosphide monocrystals grown by Czochralski method on change of microhardness, photoluminescence and edge absorption spectrum under the action of high power pulsed laser radiation has been studied. The modifications of microhardness and edge absorption curves, increases in a number of radiative recombination centers has been associated with laser stimulated dissociation of the region rich of impurities, generation of defects and their interaction with intrinsic defects.

Substrate crystallographic orientation effect on photoluminescent properties of porous silicon: Вып. 14, 2005

Etching duration and anodic current density dependences of intensity and maximum position of the photoluminescence spectra of porous silicon layers obtained by anodization of silicon wafer are investigated. The sizes of silicon nanoclusters formed during the anodization procedure are estimated. It is shown that the dependence of formed clusters sizes on etching conditions for porous layers is different for various crystallographic orientations of the substrate. The model explaining this feature at various speeds of porous layer frontal advance deep into silicon substrate is offered. Presented results may be used for optimization of etching conditions in order to obtain the porous silicon layers having the preset parameters.

Structural properties of nanocrystalline tin dioxide films deposited by electrostatic spray pyrolisis method: Вып. 14, 2005

This paper describes investigation of structural properties of nanocrystalline tin dioxide films deposited by electrostatic spray pyrolisis method. Average crystalline size measured from XRD methods was (<$E 3,5~symbol С~0,8>) nm and (<$E 5,8~symbol С~0,9>) nm for films deposited on glass and alumina substrates. Sensitivity of tin dioxide thin films to ethanol was measured under different ethanol concentrations. Annealing temperature influence on crystalline size and sensitive properties was studied.

Stochastic effect mechanism in the multi-photon processes for molecules in an intense laser field: Вып. 14, 2005

A process of multi-photon excitement into continuum within generalized kinetical equations model with an account of the stochastic diffusion mechanism in quasi-continuum is considered. A dependence of the excited molecule part q and their averaged energy eq upon density of energy of the CO2 laser pulse is calculated for the CF3I molecules. The energy threshold, at which the vibrational energy is randomly distributed among the vibrational modes during interaction with the IR laser pulse, is determined.

Stochastic dynamics of Wannier - Mott excitons and highly-excited atoms of alkali elements in electromagnetic field: Вып. 13, 2004

Dynamics of Wannier - Mott exciton and non-H, multielectron atomic systems in electric and low electromagnetic field is studied within a new version of consistent, quantum-mechanical approach - quasi-stationary, quasi-energy states method and the model potential method. It is carried out the numerical estimate of energy shift for 2S and 2Pz states of excitons in CdS semiconductor at the electric field strength ~ <$E 10 sup -5> a. u. For alkali atoms the dependencies of quasi energy upon parameters of electromagnetic field (strength and frequency) are calculated. The quantitative estimates to manifest stochasticity, quantum fluctuations, stabilization and de-stabilization in the cited systems in electromagnetic field are carried out.

Spectroscopic studies of LiF crystals irradiated with heavy ions: Вып. 13, 2004

The goal of this study is the understanding of some peculiarities of color center creation in LiF irradiated with various ions with the energy loss beyond and above of the critical value of (dE/dx)crit ~ 10 keV/nm. In the experiments optical spectroscopy in the range of 200 - 700 nm was used, as well as optical bleaching and thermal annealing. The main experimental results on radiation damage in ion tracks in LiF are presented.

Spectral characteristics of film structures CdS-PbS: Вып. 13, 2004

Sulfides of lead and cadmium form the limited solid solutions that are especially appreciable on spectral characteristics of this heterophase system [1], as initial substances of it are the known photoconductors. The purpose of the given work is to study spectral characteristics of heterophase film structures photocurrent at presence of external illumination and contact injection.

Sensitivity of disk shaped magnetodiodes: Вып. 14, 2005

It is shown the change of the neutral contact in Corbino disk by the injection contact brings to the increase of magnetosesitivity in diode structures.

Semiconductor chemiluminescent sensor for determination of the partial pressure of atoms in the gases: Вып. 13, 2004

The principles to create the semiconductor sensors to determine the atom concentration (H, O) in gases (H2, O2, O2 + Ar etc.) are described. The principles to create the sensors on the basis of semiconductor surface excited by heterogeneous chemiluminescence (HCL) owing to energy of heterogeneous atoms recombination. Conditions of work and semiconductor for non-equilibrium chemiluminescent sensors on solid are determined. It's showed, that HCL excitation of semiconductor sensor takes place as a result of impact atoms recombination by Rideal-Eley's mechanism only. It's retrieved, that to this wide band gap semiconductors <$E roman {A sup II B sup VI}> (ZnS, CdS) satisfy. The processes taking place during HCL excitation were modeled numerically using the developed excitation mechanism of heterogeneous chemiluminescence.

Radical-beam geterising epitaction in technology of <$E bold {A sup roman II~-~B sup roman VI}> semiconductors: Вып. 14, 2005

A new method is proposed to control the defect composition in chalcogenide semiconductors <$E A sup roman II~-~B sup roman VI>. To achieve an inversion of mono-polar n-type semiconductor to p-type conductivity, the crystals should be annealed in activated chalcogenide vapour at the certain temperature. The new low temperature technique for growing <$E A sup roman II~-~B sup roman VI> semiconductor structures (Radical Beam Gettering Epitaxy) is used. This technique offers the possibility to grow both n- and p-type <$E A sup roman II~-~B sup roman VI> epilayers. The technology made also possible to obtain heterostructures.

Radiation stability of IR-photodetectors: Вып. 14, 2005

The results for influence of ionizing radiation on photodetectors on the base of <$E {roman Cd} sub x {roman Hg} sub 1-x roman Te> by changes in photoresponse are estimated. The preference for devices operated in the mode of minority carriers transit is shown.

Quantum galvanomagnetic phenomena in quasi-two-dimensional hole gas confined within <$E bold {roman Ge "/" p- {roman Ge} sub 1-x {roman Si} sub x}> heterosystem: Вып. 13, 2004

Magnetoresistance and quantum Hall effect (QHE) are studied of hole gas confined in <$E p- {roman Ge} sub 1-x {roman Si} sub x "/" roman Ge "/" p- {roman Ge} sub 1-x {roman Si} sub x> quantum well (QW) within ranges of QW widths 8 - 38 nm and hole gas densities <$E (1~-~6)~cdot~10 sup 15~roman m sup -2> under magnetic fields up to 40 T and temperatures down to 0,1 K. Strong changes in the structure of QHE experimental traces are revealed when the upper subbands become populated and shown is that detailed information may be extracted from the analysis of these changes. It was found that in Ge layers wider than 35 nm hole gas is separated into two 2D sublayers located next to the interfaces. In this case the analysis of weak field magnetoresistivity yields relative characteristics of normal and inverted heterojunctions. At the intermediate stage of the self-organized formation of double QW, the quantized Hall insulator phase is discovered. For magnetic fields configured parallel to the layers, a strong negative magnetoresistance is found caused by depopulation of the upper subbands due to their diamagnetic shift in energy. Under parallel magnetic fields some additional peculiarities in magnetoresistivity of the samples with divided hole gas have been found, which are tentatively explained as being due to the complicated structure of energy dispersion surface of double QW formed in valence band.

Properties and characteristics of photocells with heterojunction structure p-(Cu2O)-n-(CdS) on a thin substrate: Вып. 13, 2004

Techniques to manufacture and to research the properties of film photocells (PhC) presented on the basis of p-(Cu2O)-n-(CdS) heterojunction, produced on thin polyamide film by thermal vacuum evaporation. The obtained samples of PhC have shown the different types of voltage-current characteristic from clearly defined nonlinear up to almost linear. The maximum efficiency of PhC is equal to 2 - 3 %. Spectral dependence of short-circuit currents PhC which shape has shown the presence of two maximums corresponding to the contribution to photoe. m. f. as from layer of CdS near to 500 - 530 nm, and layer Cu2O from 600 up to 800 nm, is investigated. The low weight of the separate PhC, equal to 20 mg, compensates insufficient magnitude of efficiency and makes it perspective for the further research and improvement of parameters.

Photoluminescence of tin dioxide thin films, obtained with the use of polymers: Вып. 14, 2005

Tin dioxide nanostructured thin films properties obtained by the photoluminescent methods are reported. As a result of the researches fulfilled the luminescence in the visible region of 577 nm and 642 nm was established which is not yet reported in the literature. The luminescent mechanism connected with the system of centers typical for nanostructured objects are analyzed. The radiation spectra types changes, caused by the thermal treatment of a nanoscale tin dioxide films were noticed, which may be connected with structural transformations. These transformations seems caused the luminescent mechanism change from the intercenters' type to the recombinational one.