The ability to hybridize various detector arrays in disparate technologies to an assortment of state-of-the-art silicon readouts has enabled direct comparison of key IR detector technologies including photovoltaic (PV) HgCdTe/Al₂O₃, PV HgCdTe/CdZnTe, PV InGaAs/InP, and the photoconductive (PC) GaAs/AlGaAs quantum well IR photodetector (QWIP). The staring focal plane arrays range in size from 64 X 64 to 1024 X 1024; we compare these IR detector technologies versus operating temperature and background flux via hybrid FPA test at operating temperatures from 32.5 K to room temperature and photon backgrounds from mid-10⁵ to approximately equals 10¹⁷ photons/cm²-s. Several state-of-the-art IR FPAs are included: a 1.7 micrometers 128 X 128 InGaAs hybrid FPA with room temperature D of 1.5 X 10¹³ cm-Hz^1/2/W and 195K D of 1.1 X 10¹⁵ cm-Hz^1/2/W; a 3.2 micrometers 1024 X 1024 FPA for surveillance; a 4.6 micrometers 256 X 256 HgCdTe/Al₂O₃ FPA for imaging with BLIP NE(Delta) T of 2.8 mK at 95K; and a 9 micrometers 128 X 128 GaAs QWIP with 32.5 K D > 10¹⁴ cm-Hz^1/2/W at 32.5K and 8 X 10¹⁰ cm-Hz^1/2W at 62K.

Investigations of the performance of IR thermal detectors as compared to photon detectors are presented. Due to fundamental different types of noise, these two classes of detectors have different dependencies of detectivities on wavelength and temperature. The photon detectors are favored at long wavelength IR and lower operating temperatures. The thermal detectors are favored at very long wavelength spectral range. The comparative studies of the thermal detectors with HgCdTe photodiodes, doped silicon detectors and quantum well IR photodetectors are carried out. In comparison with Kruse's paper these studies are re-examined taking into account updated theories of different types of detectors. The considerations are made for different background levels.

Progress in the development of narrow gap IV-VI-on-Si technology for IR sensor arrays is reviewed. Epitaxial Pb_1-xSn_xSe layers, about 4 micrometers thick, are grown by molecular beam epitaxy onto 3 inch Si(111) substrates. An intermediate CaF₂ buffer layer of only 2 nm thickness was employed for compatibility reasons in most cases, direct growth without buffer layer, however, is possible. Material quality is improved by proper growth conditions and annealing. Threading dislocation densities as low as 10⁶ cm^-2 are obtained in samples with 3 X 3 cm² size after proper anneal. It seems that glissile threading dislocations sweep out across the edge of the samples, and, in addition, such dislocations are able to react with sessile ones and transform them to glissile. IR photodiodes with much higher resistance area products can be obtained which approach the theoretical limit in a certain temperature range with such improve material quality. If the Pb/Pb_1-xSn_xSe IR Schottky-barrier sensors are described with a model which allows fluctuations of the barrier height, the saturation of the resistance-area products at low temperatures as well as ideality factors > 1 are explained as well.

The characterization of impurities, defects, uniformity and some fundamental properties for the bulk and epitaxial HgCdTe(MCT) material undoped and doped with Sb, As, Fe have been investigated recently in our laboratory by means of photoluminescence, magneto-photoconductivity, quantum capacitance spectroscopy, transport measurements and other contactless nd nondestructive methods such as the IR, far-IR and millimeter wave measurements. This paper reports a portion of these new results.

The detecting properties and sensitivity limitation of the YBCO film have been studied. The practical photoreceiving service for thermovision systems with NEP approximately 2 X 10^-11W/Hz^1/2 is described. The methods of the registration of the IR image based on the control of superconducting film coordinate responsivity are proposed.

Quantum magnetotransport measurements were performed on liquid phase epitaxially grown In_0.35Ga_0.47As/InP heterostructures at 4.2 K temperature in magnetic fields up to 22 Tesla. Measurements in tilted magnetic field, in conjunction with the analysis of the derivatives with respect to the magnetic field of the magnetoresistance curves, allowed the resolution of spin-splitting of the Landau levels up to N equals 3. The spin-splitting energy E_SPIN was deduced for the half-filled Landau levels 0$ARDN, 1$ARUP, 1$ARDN, 2$ARUP, and 2$ARDN. The magnetic field dependence of the spin-splitting energy was interpreted using a simple model based on the exchange interaction of the electrons in the spin-splitted Landau levels, incorporating the disorder induced broadening of the Landau levels.

A new type of step quantum well IR detectors with electron Bragg reflectors in the barrier regions has be proposed. The Bragg reflector is consisted of special square well and help to form the highly localized quasibound states in the extended states above the barrier height. Using the transfer matrix method, the complex eigen-energies, corresponding eigen-wavefunctions, and oscillator strengths was calculated. Theoretical analyses indicate that this kind of structure has great facility to realize bicolor optical transitions and transport asymmetry of photocurrent.

The results of the investigations of the injection photodiodes p-i-n structures, based on high-resistivity semiconductors, compensated by deep-level impurities, are presented. Mechanisms of the photoelectric injection amplification are discussed, which consists in the direct influence of light on the charge currier distribution parameters in the semiconductor volume. The diodes are shown to by sensitive in a broad spectral range. The integral sensitivity of photodetectors of this type is much higher than that of injectionless devices. The physical mechanism of the injection amplification of photocurrent in mercuri- compensated and indium antimonide under the effect of the middle IR-wavelength band electromagnetic radiation has been studied both theoretically and experimentally.

The influence of light illumination and high electric field pulses on the long-term relaxation effect in piezoresistivity which has been discovered recently in p- GaAs/Al_0.5Ga_0.5As heterostructures has ben investigated. Significant acceleration of relaxation processes has been observed under the carriers heating by different external sources. This means that these phenomena are mostly determined by nonequilibrium processes in electron system. At 4.2 K under high electric fields switching of the samples to long-term high-resistance state has ben also found.

Modulator base don the amorphous Si-Te acousto-optic cell and operating in the mid-IR region has been manufactured and tested using 3.3 micrometers diode laser based on InGaAsSb/InAsSbP double heterostructure. Amplitude modulation efficiency for the laser beam coming from the end of a As₂S₃ fiber appeared to be not less than 70 percent, allowing to use the cell in optical gas sensor applications.

Intrinsic 'quality' of chaos (IqC) as a physical concept is discussed. The possibility is shown to introduce a self- sufficient concept of the intrinsic pat of a random physical value which acts like a whole invariable quantity of the concrete stochastic physical process. This IqC has no fundamental association with the quantum physics in principe, though quantified physical quantities can also be adequately acting like to IqC at proper circumstance. Physical situations considered in the frame of which the concept of IqC could be substantiated. The statement is proposed: if a physical value F is additive and its fluctuations are statistically independent then the variance of the F may be expressed in the form of the product of the mean value and the IqC.

Attention is concentrated on the original results of investigations of pyroelectric effect and related phenomena in various ferroelectric materials (FEM) used for creation of pyroelectric convertors for various purposes including single and multielements pyroelectric detectors of radiation (PDR) of plane and cavity types. Methods of pyroelectric certification developed for both simultaneous determination of pyroelectric, piezoelectric, dielectric and thermal parameters of pyroactive FEM and express selection of sensitive elements of PDR and pyrovidicons in conditions of mass production are considered. The results of amplitude- phase-frequency analysis of dynamic pyroelectric response under near-surface pyroelectric probing of multilayer contact systems based on wide used traditional dielectric FEM, on photosensitive FEM with semiconductive properties and ionic conductivity, namely ferroelectric-semiconductors and ferroelectric-ionics and also polymeric FEM of PVDF-type are presented. The applications of a number of effects connected with high pyroactivity, thermo-, photo- and electrical controllability characteristic for such FEM are discussed. The examples of practical realization of new principles under development of pyro- and photoelectric convertors, pyroelectric devices and units of electronic support are given. The peculiarities of PDR operation in pyroelectric current and voltage mode are discussed.

High resistivity Ge-doped crystals with exact defined by radiometric analysis Ge contain were characterized by IR microscopy, dislocation etch techniques, scanning electron microscopy followed by detector performance features examination. the influence of several defect structure types on detector parameters were shown.

P-channel silicon direct injection read-out devices with p- type buried channel CD multiplexers which consist of input circuits, shift register and output circuits were designed, fabricated and tested. Read-out devices were designed for using with IR p-n-photodiode linear arrays. The dynamical range of p-type read-out devices was estimated to be of the order of 60 dB at T equals 80 K. The two-phase p-channel CCD shift register was designed with 5 MHz clock frequency operation. Transfer efficiency without fat zero was 0.99985 at 1.0 MHz.

We inform on results C-V measurements of structures metal- insulator MnHgTe, in which interface insulator-MnHgTe is created anodic oxidation. Results of researchers of a structure of distribution of elements of a matrix on interface by a method Rutherford backscattering spectrometry are submitted. Interrelation between the characteristics of interface and C-V characteristics is shown. MIS-structures on MMT as with anodic oxide and with oxinitrid silicon deposition after removal anodic oxide. A nature of defects of a transient layer between oxide and MMT is discussed which requires further research. Passivation MMT by deposition Si_xO_yN_z allows to reach rather low concentration surface charge, that on the order is lower, than with anodic oxide.

Epitaxial films Pb_1-x-yGe_ySn_xTe:In grown by 'hot wall' method on insulating substrates BaF₂ are studied. Samples are made in Ukrainian Institute of Problems of the Study of Materials. Measurements of photoconductivity spectra and temperature dependence of resistance are carried out at different background fluxes. The correlation between a cutoff wavelength and thermoactivation energies of resistance of studied samples was observed. The observed phenomena are explained on the basis of a two-electron Indium impurity center model. Energies of local oscillations of impurity centers are determined.

The software representing a complex of tools for simulation, optimization, and characterization of planar gradient waveguides is developed. Up-conversion of the CO₂-laser IR signal under semiconductor laser pumping in nonlinear optical planar waveguides based on solid solutions GaAs in GaP is simulated. Parameters of waveguide composition profiles with the various forms are optimized.

We proposed a new physical model and results of numerical calculations. According to this model, 2D concentrations of ion-implanted impurity profiles with initial distribution Pearson-IV's type under pulse laser influence. Exclusive character of this model was connected with registration action not only concentration gradient but also internal thermodiffusional stress, thermoelectric fields and parallel calculation of evolution temperature-coordinate field dependence in CdHgTe crystal with taking to account temperature dependencies of thermoconductivity and density of material. Using numerical implicit method for solving set of nonlinear nonstationary differential equations we investigated processes of side diffusion of ion-implanted in CdHgTe impurity near edge of defense mask.

This paper reviews an attempt to formulate requirements for the semiconductor materials which arise in thermal radiation detection by means of a photodetector when the radiator is of small size or it consists of aggregation of small emitters. Practical necessity of the analysis is connected with the problem of adequate identification of the small objects. This seems to be of interest because of wide spread of IR vision into a new area of applications of science and technology. The above reasons require to take into account the physical peculiarities of the emitters to determine the real capabilities of the detectors. Restrictions of mode number of a blackbody radiator within the cavity of a small fixed volume were examined in connection with photo detecting process. The role of size-correction in the thermal radiation distribution, specific detectivity and the detecting time have ben shown. Critical values of mean size of the cavity which control character of fluctuation and statistics of signal processing were evaluated. Specific requirements for the sensitive materials of photo detector were described.

High purity In_0.53Ga_0.47As grown on InP by liquid phase epitaxy with small amounts of rare earth dysprosium (Dy) in the melt was investigated. The presence of Dy dramatically reduced the charge carrier and residual donor concentration, and shifted the low temperature photoluminescence peaks toward higher energies. Room temperature Raman spectra were also studied. The Raman shift of the GaAs-like longitudinal optical phonon band increased with the Dy content in the growth melt. The results were explained by the effect of gettering of unintentional donor impurities in the melt by Dy, as well as by the effect of strain modification in the layers due to the possible incorporation of Dy.

The Al_xGa_1-xAs/GaAs heterostructures represent a potentially useful material for photodetectors with high efficiency in spectral range 0.4 divided by 0.9 micrometers . To produce the thermostable detectors with high radiation hardness on the base of liquid phase epitaxy (LPE) the physical and chemical foundation of such epilayers formation was developed. The abilities of LPE method wee improved due to utilization of multicomponent solution-melts with rare-earth additions. The horizontal sliding-boat step-cooled LPE technique with controlled composition of gaseous medium and additions of Yb in Bi and Ga-Bi-Al solution-melts was used as the base of technology. As a result of our investigation the quickly responsive photodiodes with improved technical, exploitative and economical parameters were produced.

The rate of tunnel surface recombination (TSR) in a p-n structure has been calculated as a function of the excitation level and temperature in a semiclassical approximation under the assumption that the excess energy of a recombining electron is transferred to phonons or to a photon. The approximating analytical expressions obtained are applied in calculations of the effect of TSR on the characteristics of photodiodes, solar cells, light-emitting diodes and diode lasers.

The strong photoeffect was discovered experimentally in specially doped InSe crystals at temperature 4.2 K as a result of laser radiation action at fixed wave-lengths of 337 and 195 microns.Also some of the kinetic, galvanomagnetic and optical anomalies had been observed. They are explained by appearance of the gap E in the conduction band continuum of degenerated 2D semiconductor in charge density waves state. The long wave threshold of photocurrent was found to depend strongly on a magnitude of electric current through the crystal. A rough estimation gives a value dE/dJ approximately 0.4 meV/mA. We had carried out experiments in order to study instabilities of InSe electrical properties in temperature range 4.2 approximately 300 K by quasi stationary conditions. Abrupt electrical resistivity increases about 5 times were observed by us at temperatures 5, 10, 14, 27, 31, 170 and 200 K. The frequency dispersion of conductivity for high frequencies were observed.

Epitaxial Mn_xHg_1-xTe layers grown by the liquid phase method at temperatures 848K and 793K are investigated. Due to diffusion of Cd from substrate Cd_0.96Zn_0.04Te obtained layers are four-component. Results of conductivity and Hall measurements show that the graded-gap layer gives noticeable contribution to the transport characteristics.

Nonlinear optical transmission in single Cd_0.2Hg_0.8Te crystals in the range of fundamental absorption at high laser intensity level was investigated at 298K. For thick samples the decease of light transmission up to five times was registered at wavelength length (lambda) equals 10.6 micrometers and at laser intensity level 300 kW/cm². It was explained by new channel of absorption: two-level transition of the electron inter-intra-band increase under the laser pulse influence.

The performance of electronic devices such as field-effect or bipolar transistors is determined by extrinsic factors such as wiring, intrinsic technology such as metalization and contact resistance, transit lengths, and capacitances, and by transport characteristics of the material itself. The electronic transport characteristics are in turn largely determined by the electronic bandstructure. This bandstructure can be altered or engineered through the use of strain and quantum size effects in artificially structured heterostructures, allowing improvements in device performance.

We report on the dynamics of the transport processes which determine the photoresponse of quantum well intersubband IR detectors. Immediately after intersubband excitation, coherent transport is important. This process can be identified via interference effects between photoexcited carriers. The carriers are re-captured subsequently within a few picoseconds. These fast transport processes give rise to space charges, which induce an additional, slow component of the photocurrent in the ns to microsecond(s) regime.

The kinetics of photoconductivity and the spectral photosensitivity of a semiconductor with anisotropic electroconductivity in nonhomogeneous electric field has been investigated. Photoconductivity of germanium samples of ringlike geometry was studied experimentally and theoretically. The main results are: decay of the photocurrent in a semiconductor in the presence of the transverse gradient of electric field differs form the exponential one and depends on mutual directions of the gradient and the drift of the carriers; a photodetector with parameters reversibly controlled by electric and magnetic fields is possible. It was found that spectral photosensitivity is of either selective or bolometric type depending on mutual directions of incident light, the gradient of electric field, and of drift of carriers.

(Pb,Sr)Se and (Pb,Eu)Se are semiconductors with sodium chloride structure. They exhibit a direct energy gap which opens very sharply with increasing SeSe or EuSe content in the PbSe matrix. This is of interest for optoelectronic applications in photodetectors, injection lasers as well as for waveguides and cladding layers in quantum well and heterostructures in general. A detailed analysis of the optical, magnetooptical, photoelectric and photoluminescence properties of MBE-grown layers on BaF₂ substrates with energy gaps up to 500 meV at temperatures between 10 K and 300 K is given. The discussion is concentrated on the following points: character of the near-to-edge optical transitions, influence of Coulomb interaction on the spectra; dispersion of the refractive index and the enhancement near Eg; differences between (Pb,Sr)Se and the dilute semimagnetic (Pb,Eu)Se; applications in optoelectronic devices.

Diffusion lengths of minority electrons and holes in Hg_1-xCd_xTe single crystals produced by the diffusion controlled Bridgman growth from melt of constant composition were studied. Bulk p-HgCdTe samples were etched by low energy Ar ions in the VEECO ion etching system or in Ar plasma in a plasma etching reactor. As a result of this treatment a deep p-n junction was created in the samples. Secondary-electron and electron beam induced current images were used to determine the position of the p-n junction. The obtained EBIC data were then sued for evaluation of a set of minority carrier diffusion lengths at temperatures 140-270 K.

Spectroscopic ellipsometry and Raman spectroscopy have ben sued to characterize Si/Si_0.78Ge_0.22 superlattices grown by molecular beam epitaxy at different substrate temperatures, 550 degrees C < T_s < 810 degrees C. The result are interpreted to give information on material and interface quality, layer thicknesses, and state of strain, and are in good agreement with XRD, SIMS and RBS investigations. The observed frequencies of zone-folded longitudinal acoustic phonons in a high quality sample agree well with those calculated using Rytov's theory of acoustic vibrations in layered media.

The most important features of Pb_1-xMn_xTe(In) solid solutions are the effect of Fermi level (FL) pinning and the existence of metastable electronic states resulting in the appearance of the relaxation processes of long duration. The increase of MnTe content in Pb_1-xMn_xTe(In) leads to the shift of pinned FL towards the conduction band edge E_c and metal-dielectric transition at X approximately 0.05. The kinetic processes under the radiation of Pb_1-xMn_xTe(In) single crystals have been investigated in the temperature range 4.2-35 K. It has been found that under the composition X variation the view of kinetic curves changes qualitatively. At X 1 of the impurity center together with the ground one E₂ is assumed. It is shown, that if the shift of E₁ and E₂ levels relatively to E_c is characterized by the linear dependence on X, the fast relaxation appears near the point when E₁ level crosses E_c and enters the energy gap.

The effect of deep electron irradiation on the galvanomagnetic and photoelectric properties of p- and n- type PbTe single crystals doped with gallium have been investigated. It has been found that electron irradiation of p-type samples results in the decrease of the holes concentration, the p-n-conversion and the transition of irradiated crystals to a dielectric state. In all investigated samples long-term relaxation processes and effect of persistent photoconductivity at low temperatures have been revealed. Under the electron irradiation the photoresponse in the p-type samples with low gallium concentration monotonously increase up to the point of transition to the dielectric state. In the dielectric state gallvanomagnetic and photoelectric parameters of the samples do not depend on the irradiation fluence whether it has been achieved by means of sufficient doping or slight initial doping followed by the electron irradiation and PbTe doped with gallium possesses high radiation hardness of galvanomagnetic parameters.

One of possible attempt to get light emission out of silicon is to use low dimensional Si structures. There we report about nanocrystalline composite Si films with visible photoluminescence prepared by reactive pulsed laser deposition. We have examined the effects of nanocrystallite size and matrix composition on the optical properties. As a result, the structure of these composite films and superlattice based thereon have the ability of controlling the quantum size and consequently their optoelectronic properties.

The second harmonic generation due to the intersubband transitions in the doubly resonant nonparobolic quantum well systems is discussed theoretically, employing the self- consistent field method. It was shown that the correct description of the modification of the second-harmonic generation spectrum resulting from the nonparabolicity of the subbands have to take into account the depolarization effect.

The in-plane electron mobility limited by the interaction of the degenerate electron gas with the confined LO-phonons is investigated in the extreme quantum limit. The layered structures PbTe/PbSnTe with axes < 111 > are considered. A square quantum well approximation is assumed for the calculations. The influence of Kane's two-band energetic structure of the electrons is taken into account. It is shown that the manifestations of the non-parabolicity of the electron energy dispersion law in quantum size case are twofold: (a) as a bulk-like non-parabolicity, considerably reducing the calculated mobility, (b) as effective mass quantization whose influence on the mobility arises at small quantum well width.

PbS-based optical sensors are sensitive in the IR-region of the spectra and are important for a lot of applications in optoelectronic field. Photoelectric properties of thin polycrystal PbS films prepared by a new spray method have ben investigated. This method allows of a smooth change in the dosage of oxidant concentration in the initial solutions, which influences the parameters and characteristics of produced samples. Large scale temperature dependencies of dark and photo currents, volt-watt and volt- ampere characteristics, electron beam microscopy of films surface were investigated. A very low value of relaxation time of photoexcitation is the characteristic property of the prepared films. Volt-ampere characteristics of the dark current are superlinear at high voltage, and, in case of photo current, have a section of the negative differential conductivity. Calculated are the reduced chemical potentials for holes and electrons and its concentrations n, p and degeneration criteria (eta) _i for a row of temperatures: 4.2K, 77 K, 300 K. It was shown, that a hole gas is degenerated at low temperatures and particularly degenerated at room temperatures. Suggested is a model that explains experimental results by means of a concept of degeneration areas in 'noes' of inverse channels net and tunneling of minor carriers through oxidant barriers on crystallite borders. Furthermore, a diffusion length 1 and a transparency D for oxidant interlayers were calculated for different temperatures in accordance with barrier model. The tunnel component of dark current as a function of the supplied voltage was calculated theoretically. Analytical dependencies correlate well with experimental results.

Peculiarities of photovoltaic effect (PVE) in graded-band- gap (GBG) layers with intrinsic type of conductivity and linear coordinate dependence of energy gap in the conditions of layer illumination by strongly absorbed monochromatic light are investigated theoretically. It is established that sign reversal of the photoEMF takes place on the spectral dependencies of PVE in the case when light is incident on the wide-gap of the layers. The dependence of PVE reversal point on the energy gap gradient and surface recombination velocities of charge carriers is analyzed. The photoEMF of GBG layers illuminated from narrow-gap side is shown to essentially exceed the photovoltage of uniform samples with the same energy gap as at narrow-gap side of GBG layers.

The effect of high hydrostatic pressure on the galvanomagnetic properties of n- and p-Pb_1-xSn_xTe irradiated with electrons has been investigated. It has been shown that independently of the initial type of conductivity under the electron irradiation the Fermi level in Pb_1-xSn_xTe alloys reaches the limiting position and 'soft' pinning of the Fermi level in the valence band occurs. In all irradiated alloys the reconstruction of the energy spectrum under pressure leads to the increase of the hole concentration due to the redistribution of electrons between the valence band and the radiation-induced resonant states situated slightly below the valence band top. On the basis of the obtained experimental results the model of the energy spectrum of irradiated Pb_1-xSn_xTe alloys has been discussed. In terms of this model by comparing the experimental and theoretical fluence and pressure dependences of the free carriers concentration the main parameters of irradiation- induced defect states in Pb_1-xSn_xTe alloys were determined.

In this paper we propose the new method of ultrasonic sensitive centers study. The semiconductor samples are measure by Hall effect method and simotaneously are exposed to ultrasonic treatment. Ultrasound acoustoactivates any centers which don't be activated under ordinary conditions and can't be displayed by the ordinary Hall method. Such temperatures (80:350 K) investigation with ultrasonic influence (time and amplitude dependences also) significantly increases and completes Hall method possibilities. The crystals of neutrontrasmutation dopes Ge:Sb were studied.

The analysis of photoconductivity (PC) spectra in PbTe(Ga) single crystals and films shows that a pronounced photoresponse is observed at an energy approximately 20 meV less the energy gap value. The relative amplitude of the sub-band photoresponse depends on the method of the crystal synthesis, but its energy position does not depend on temperature or growth technique. For PbTe(Ga) thin films the structure of the absorption edge is similar to undoped PbTe and amplitude of the sub-band photoresponse appears to be small. The phenomenological description of the PC kinetics of the investigated samples under the IR-radiation of pulse and heat sources is done. It is established that under the radiation with pulse duration 10 mcs the characteristic relaxation times are 10^-3 s at 4.2 K, and the persistent PC can be observed only under the continuous radiation at T < 80 K. Moreover, at low intensities of the continuous radiation PC relaxation time is about 1 ms and only the increase of radiation intensity results in appearance of the persistent PC with the relaxation times of 10⁵ s. We propose a phenomenological model of energy spectrum and impurity states in PbTe(Ga), which is able to describe the experimental data. According to this model the metastable impurity states 20 meV lower the bottom of the conduction band exist in addition to the ground states 70 meV lower the bottom of the conduction band. The increase of the radiation intensity provides the growth of the metastable states concentration and the impurity band formation. So it can be concluded that PbTe(Ga) may be considered as an advanced material for the multispectral photodetectors operating in near IR-region if the ground state electrons are excited and in far IR-region if the excited from preliminary induced metastable states.

Influence of a weak magnetic field on photo-electric, electrophysical characteristics of MIS - structures is experimentally investigated.Long-term changes of a spectrum of surface states of Si-SiO₂-structures, caused by a magnetic field are considered. It is supposed that the reason of a long-term relaxation in Si-SiO₂ - structures are a diffusion and reactions of nonequilibrium defects, arising at relaxations of polarization of nuclear spin system, in InSb, InAs the diffusion passes on mechanism of transfer of defect of a type 'broken off connection'.

Optical and photoelectrical properties of both as-grown and annealed at 600 C during five hours CdTe:V crystals with Vanadium concentration in liquid phase of 5 X 10¹⁸cm^-3 and 5 X¹⁹cm^-3 were investigated. Presented data are based on investigation of photoluminescence (PL) spectra and spectral dependence of photoconductivity (PC). The effect of PL band kindling has been detected with maximum at 1.55 eV in crystals of N_v equals 5 X 10¹⁸ cm^-3 doping concentration. The effect is accompanied by dramatic increase of crystals' resistance. As mechanism responsible for formation of high- resistance state the self-compensation of the impurities with creation of complexes that include isolated Vanadium and vacancy in the metal sublattice is considered.

The temperature and concentration dependences of the thermal conductivity of the PbTe-MnTe solid solutions in the range of (170 divided by 670) K were obtained. THE existence of minima in all the curves in the region of (400 divided by 450) K is related to appearance of intrinsic conductivity. The estimation of contributions into the thermal conductivity made by different factors was carried out. The effective cross-section of phonon scattering under doping with Mn was calculated.

Phonon-assisted self-trapping of free carrier is considered in diluted semimagnetics. It is shown that the binding energy of free magnetic polaron can be substantially larger when the 'spin-phonon' coupling is taken into account. For the particular case of 'soft' lattice dynamics the region of stability for hole-induced polaron can be promoted to the temperature of tenths of degrees and magnetic field of a few Tesla. The possible hybridized excitations with the partition of free magnetic polaron are discussed in semimagnetic semiconductors.

High-conductivity semiconductor films with low reflectance in the IR-region can be used as absorbing coatings of pyroelectric radiation detectors. The plasma reflectivity of InSb-CdSe and InSb-CdS solid solutions were studied both experimentally and theoretically. A computer simulation was made of the dependences of spectrum shape nd plasma minimum depth on the relaxation time (tau) and sample structure inhomogeneity parameter (Delta) . The calculated reflection spectra with suitable selection of (tau) and (Delta) were found to agree well with the experimental ones. The results can be used for reflecting structure inhomogeneity diagnostics.

The influence of the deformation on the magnetic susceptibility of molybdenum and zinc single crystals in the range 77 divided by 300K at the magnetic fields 0,03 divided by 2.5KOe has been investigated. It is deduced that the increase of a deformation degree causes the essential growth of paramagnetism and the occurrence of nonlinear susceptibility dependence on the intensity of a magnetic field. At room temperature and H < 100Oe the abnormal diamagnetism increase have been observed. This phenomenon can be explained by the occurrence of superconductive phases in the bulk of the crystal. We have established that the ten-fold abnormal diamagnetism increase is observed for (InSb)_0.95(CdTe)_0.05 solid solution when the temperature falls. This phenomenon can be explained due to the emergence of metal superconductive modifications in the bulk of the crystal.

Characteristic features of the photoelectric amplification of graded-band-gap photoresistors which energy gap is increased linearly towards contacts are considered theoretically. It has been shown that nonmonotonic field dependence of the photoelectric amplification coefficient is realized in such photoresistors. Maximum value the photoelectric amplification coefficient being increased under the increase of energy gap gradient can be much greater than that of the homogeneous samples.

Electrical and magnetic investigations of HgTe with substitution of Cr and Cd_0.2Hg_0.8Te substituted by In are represented. Common behavior and difference is of action of these impurities on A^IIB^VI properties are shown. Extraordinary temperature dependence of thermoelectromotive force of HgTe:Cr is observed.

Purposeful changes of the properties of Cd_xHg_1-xTe (CMT) semiconductors by irradiation with nanosecond ruby laser pulses were studied in order to obtain structures with desired physical parameters. An investigation was made of photoelectric, electrophysical properties and structure of different CMT solid solutions. Irradiation of CMT with laser pulses of subthreshold energy density modified the point-defect structure in the surface layer leading to an improvement homogeneity of samples. An increase in the energy density shifted the maximum and the long-wavelength edge of the photoconductivity spectrum toward shorter wavelengths. It was established that laser pulses can be used in producing both a p-n-junction in n- type crystals and the surface p⁺-region in p-type solid solutions. Pulse laser irradiation increased the photosensitivity of the epitaxial CMT layers with a cellular structure.

The irreversible gigantic modification (IGM) occurs in semiconductors under simultaneous action of strongly polar liquid, acceptors dissolved in it, and optical radiation in the region of fundamental absorption. The IGM phenomenon is found by the authors in the III-V and II-VI compound semiconductors. During the IGM process the reflection and transmission coefficients are gradually varying in a modified near-surface semiconductor region. This enables to reduce controllably the real part of the complex refractive index in a near-surface semiconductor region, vary its chemical composition and the luminescence spectrum. After IGM the modified semiconductor with the velocity of 100 ms/mm. Increasing a distance between the controlling and controlled beams enables to implement a time delay between signal. The time delay up to 1.7 seconds has been achieved experimentally. We have used the IGM phenomenon to fabricate elements and devices of the integrated semiconductor optics. The IGM phenomenon enables to make antireflective optical elements.

The effect of the deposition rate, the substrate temperature, the annealing temperature, the laser and high energy electron irradiation on the mechanical stresses for the heterostructure obtained by thermal evaporation of Ge₃₃As₁₂Se₅₅ film onto the crystalline p-Si has been investigated. It has been found that the mechanical stresses are the tensile ones and are in the range between 1 X 10⁷ Pa and 1 X 10⁸ Pa dependent on the film structure related to the deposition technique. Special features of the stresses changes at the deposition rate 6.0 nm/s and the substrate and the annealing temperatures 450 K has been revealed. The results have been interpreted in terms of the topological structural transition associated with the transition from the 2D structure to the 3D one.

Faraday rotation, absorption spectra, and the intrinsic carrier concentration temperature dependencies were investigated in order to determine the interconsistent system of values of the narrow-gap Hg_1-xCd_xTe band parameters. The undoped and doped with indium or copper crystals with x < 0.315 were studied. The analysis of data of measuring was made with account of the far band influence. The value of matrix element P equals (8.1 +/- 0.08_ X 10^-8 eV cm have been obtained with a high degree of certainty. The parameters of the second approach of the Kane model were found too: (gamma) ₁ equals 4.0; (gamma) equals 0.7; (gamma) _s equals 0.5. A new method of determination of the heavy hole effective mass have been elaborated and have been used successively in the heavy hole energy range (epsilon) < 0.15 eV. A new form of the light carrier dispersion relation and more exact relation for the temperature dependence of (epsilon) _g have been obtained too. The heavy hole Hall factor at T equals 77 K, the heavy hole mobility at T equals 295 K, and the constant of valence band deformation potential E₁ equals 12.5 eV have been determined. It has been found that doping of the material with indium, causes the appearance of donor states in the conduction band about 0.1 eV above the bottom of the band. The band structure of Hg_1-xCd_xTe (MCT) is studied for a long time, and its peculiarities are well known. The light carriers spectrum is believed to be described in framework of the 3-band Kane's model, and the parabolic approximation for heavy hole subband is thought to be sufficient as a rule. The influence of far bands is taken into account rather seldom. But at the same time, the values of band parameters obtained by different authors are not in a good agreement often. In result, it was impossible to agree with an acceptable accuracy the measured and the calculated values of some physical characteristics of MCT by using the known values of band parameters. In order to achieve perfect conformity between the theory and the experiment, another approach must be used. It is necessary that the complex experiment be carried out with a high accuracy of not only the measuring, but of the mathematical models of studied effects and the calculations too. All the main sources of systematic error should be revealed and removed, and the values of band parameters should be determined over again. Such a study was carried out, and its results are reported in this paper.

We have carried out experimental investigation of spectral and temperature dependences of photoconductivity in n-type Hg_1-xMn_xTe and studied an influence of nanosecond pulses of ruby laser irradiation on such properties. It has been shown that irradiation of the samples with subthreshold energy densities does not cause a change of their photosensitivity and leads to the surface refining from impurity atoms and oxides. A laser treatment of the samples with energy densities E > Eth stimulates a rise of the defect number in the crystals that causes a change of the lifetime characteristics and photosensitivity lowering.

In this paper, work carried out in recent years at Coventry University on the diffusion of Hg in CdTe is reviewed, and where relevant, a comparison is made with other published work in the same material. CdTe is used extensively in the fabrication of IR devices using (Hg_0.8Cd_0.2)Te. The majority of the diffusion anneals were carried out in sealed silica capsules under saturated vapor pressure conditions due to Hg and the Hg concentration profiles were measured using a sectioning techniques. As is customary with II-VI materials, two component profiles were obtained in the majority of cases. It was found that the diffusion of Hg in CdTe is rate limiting volume diffusion involving a slow stream and a fast stream. From pressure dependency measurements it is proposed that the slow component occurs by an interstitial mechanism at low values of P_Hg and a vacancy mechanism at high values. In addition the diffusivity for the slow component increases systematically with etch pit density whereas the diffusivity for the fast component is independent of etch pit density. Both the Arrhenius plots of D and C_o show a sharp change in gradient at 275 degrees C. When compared with the results reported by other workers there is considerable agreement, particularly at high temperatures, but at low temperatures there are distinct differences. The values of the Hg diffusivity in CdTe are independent of x in (Hg_xCd_1-x)Te in the range 0 < x < 0.03 but is much less than for corresponding values in (Hg_0.8Cd_0.2)Te.

Fourteen A²B⁴C₂⁵- and A¹B³C₂⁶-compounds with chalcopyrite-type crystal structure are under investigation. The process of formation of a sole ternary compound form chemical elements is dealt with. Design-based model anticipates adiabatic conditions. Characteristics of the self-propagating high-temperature synthesis such as adiabatic combustion temperature, initial temperature of synthesis process, share of liquid phase in combustion product are calculated.

The concentration dependences of unit cell parameter, the x- ray liens width, microhardness, electrical conductivity and the Seebeck coefficient for the Pb_2-xGe_xTe alloys were obtained. Anomalies of physical properties were revealed in the range of x approximately equals 0.008-0.02. The obtained results prove existence of concentration phase transitions occurring in any solid solution and are associated with percolation effects in impurity subsystem of crystal when percolation threshold is reached.

The technique of InAs_1-x-ySb_xBi_y/InSb heterostructures forming by LPE was developed to obtain semiconductor material with intrinsic absorption edge (gamma) > 8 micrometers at 77K. Smooth epilayers with x equals 0.88-0.97 and y equals 0.0016-0.0036 were grown on InSb(111)A substrates in 380 450 degrees C temperature range. E_g(77K) values, obtained from optical absorption spectra measurements, were found to decrease by 0.017-0.020 eV as compared to InAs_1-xSb_x with the same x. The possibilities of InAs_1-x-ySb_xBi_y/InSb strained multilayer heterostructures as semiconductor material for long- wavelength applications have been analyzed. Results of our calculation demonstrate that the strain-induced energy band- gap shift in such structures enables the attainment of 0.07- 0.15 eV E_g values at 77K for 0.82 < x < 0.94 composition range. The obtaining of strained multilayer heterostructures with layer thickness 1-x-ySb_xBi_y/InSb_1-yBi_y/InSb multilayer heterostructures with epilayer thicknesses from 0.05 to 0.2 micrometers depending on growth conditions can be successfully obtained by LPE.

Hg_1-xCd_xTe(MCT) samples epitaxial structures are irradiated by pulse electron beams under the doze 10¹³- 10¹⁷ cm^-2. Electron beams have the next parameters: 500 eV energy electron ; 200 keV energy electron. Electroconductivity and recombination of modified samples are investigated by Hall effect and photoconductivity methods. For 200 keV electron energy beam irradiation of the n-type surface regions have been obtained under threshold mechanisms of donor defect generation.FOr 500 keV electron energy beam irradiation the maximum value of charge carrier lifetimes occur in p- to n-type conductivity conversion range for the initial p-type crystals due to the conductivity compensation. MCT samples are implanted by Al ions under the dose 10¹²-10¹⁶ cm^-2. Ion beams have the next parameters: (1-10) A/cm² ion current density; (100-200) ns current pulse; (150-450) keV Al ion. The ion distribution and doping profiles were investigated by PIGE and Hall effect methods. The comparison between MCT samples after power pulse ion implantation and after standard ion implantation demonstrate a difference in ion distribution, doping profiles and defect formation radiation mechanisms.

The comparison of actual manganese concentration in (Hg,Mn)Te samples grown by liquid phase epitaxy on CdTe and Cd_0.96Zn_0.04Te substrates to values obtained from the phase diagram of Hg-Mn-Te system reveals considerable discrepancies. The thermodynamic analysis made in assumption that the manganese concentration in the melting is low strained solid phase and superolled liquid one, i.e. the crystallization process is affected by elastic strain in epitaxial layer caused by lattice mismatch between substrate and film. It is shown also that the model of complete association in liquid phase do not provide a good agreement with experimental data.

Ion beam milling effect on electrical properties of usual vacancy doped and especially In compensated p-Cd_xHg_1-xTe has been investigated. In all cases after ion beam milling by low energy neutralized. Ar ions n-p structure with thickness of n-layers that depended on initial hole concentration and irradiation dose has been created. It was shown that in the usual vacancy doped Cd_xHg_1-xTe the electron concentration in n-layers well agrees with concentration of residual donors. For the especially doped samples the electron concentration was determined by the In donor impurities' concentration. The possibility of the n-p⁺ Cd_xHg_1-xTe photodiode fabrication with optimum required carriers' concentration both in n- and p-regions has been demonstrated by ion beam milling of the especially doped samples.

The diffusion and solubility of Ge in CdTe and Cd_0.96 Zn_0.04 Te crystals at near saturated cadmium vapor pressure at 838 - 1108 K has been studied by radiometric and optical methods The influence of thermal etching process on Ge diffusion rate are discussed. The result suggest that local stress field in II-VI crystals are the sites where migrating Ge had been concentrated in separate phase form.

Atomic-scale epitaxial BaTiO₃ (BTO) thin films were grown on SrTiO₃ (STO) substrate by computer-controlled laser molecular beam epitaxial system. The crystal quality, surface and interface microstructure of the laser MBE BTO thin film has been investigated by in-situ reflection high- energy electron diffraction, x-ray diffraction, transmission electron microscope and atomic force microscope. We find that the laser MBE BTO thin film prepared at ozone pressure of 10^-6 Torr and at STO substrate temperature of 750 degrees C has highly c-axis oriented tetragonal phase and single crystal structure, the BTO/STO interface is abrupt, and the surface of the BTO thin film shows atomically smooth.

The presence or the absence of the chemical reciprocal interaction of the II-VI, III-VI and IV-VI semiconductor compounds with metals can be estimated with sufficiently reliability according to the temperature dependence of the thermodynamic Gibbs potential. The character of the initial component interaction in the binary systems, which limit each concrete tenary system, must be taken into consideration.

On the samples of lead-tin telluride the possibilities of native oxides application in IV-VI photodiodes technology were shown. It is demonstrated that usage of a thin chemical oxide as an intermediatory layer between metal and semiconductor improves the Schottky barrier properties while anodic oxide passivation raises thermal and temporal stability as well as lowers the scattering of parameters from element to element in multi-element linear arrays.

Magneto-reflectivity spectra are studied to determine giant spin splitting (GSS) of the excitonic transitions in a set of quantum wells Cd_1-xMn_xTe/CdTe/Cd_1-xMn_xTe of different widths. Paramagnetic enhancement of the excitonic state GSS in the quantum wells is observed. Corrections to the GSS in the quantum well due to both a) reduction of the number of nearest neighboring magnetic ions with strong antiferromagnetic coupling at the CdTe/Cd_1-xMn_xTe interfaces and b) mixing of materials of CdTe and Cd_1-xTe in the interface region are calculated. It is shown that relative role of the paramagnetic enhancement increases as the quantum well width rises. It is noted that paramagnetic enhancement results from the weakening of two factors of the antiferromagnetic Mn-Mn coupling in the semicmagnetic semiconductors which usually tend to decrease GSS. Those factors are excluding of the part of magnetic ions contribution to the magnetization due to the antiferromagnetic coupling and account for the effective temperature of the magnetic ion subsystem.