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The problem of stretching a plate with a central or lateral crack is considered. The previously obtained solution, which determines the stresses in the plate in the vicinity of the central crack, is used to predict the load at which plastic deformation appears in the plate with a lateral crack. The Mises condition is used as a criterion for plasticity. The calculation results are compared with the experiment carried out on plates made of aluminum alloy, brass and steel.

The problem of tension of a plate made of a brittle material with a central through crack is considered. The traditional approach to solving the problem of strength of brittle bodies, which is based on linear fracture mechanics, is discussed. The apparatus of a generalized theory of elasticity, which is based on analyzing the state of stress in a medium element having small but finite sizes, is used to solve the problem of crack.

Matrix photosensitive elements based on a HgCdTe semiconductor solid solution on silicon substrates with 640 × 512 elements at a pitch of 25 μm with a long-wavelength sensitivity of 5 μm at half maximum are designed and produced. The scheme and topology are developed according to which matrix multiplexers with 640 × 512 elements at a pitch of 25 μm, which ensure operating modes at a clock frequency up to 10 MHz, are manufactured. Using a hybrid assembly method on indium bumps, a matrix photodetector with 640 × 512 elements at a pitch of 25 μm is produced. The best photodetector specimens are characterized by the following parameters: average NETD value 99.5%.

—Design and fabrication of photosensitive array elements in the 384 × 288 element format with a step of 25 μm with a long wavelength limit of sensitivity at 0.5 to approximately 9.5 μm were performed. The circuit and topology were developed, according to which matrix high-speed multiplexers are manufactured in the form of 384 × 288 elements with a step of 25 microns, which provide operating modes at a clock frequency of up to 20 MHz. The 384 × 288 element hybrid photodetector (PD) format in 25 μm increments has an average Noise Equivalent Temperature Difference (NETD) of less than 30 mK, while the number of working elements was more than 97%. Examples are given of using the microscanning system to reduce defective pixels in an image frame and/or increase the frame format to 768 × 576. It is shown that as a result of the use of microscans in a thermal imaging channel based on the developed PD during the transition to the 768 × 576 format, an improvement in spatial resolution of 1.4 times was obtained for the same minimum resolved temperature difference (MRTD), while the MRTD at a frequency of 0.44 mrad-1 decreased from 1.6 to 0.9 K compared to the original 384 × 288 format.

The influence of characteristics of ligands and nickel complex compounds on the rate of the autocatalytic (chemical) deposition of nickel–phosphorus coating and the phosphorus content is considered. It has been established that the charge and complex of the ligand have the highest effect on the rate of process, and charge number and stability of the complex ion have the highest effect on the content of phosphorus in the coating. Mathematical models describing the relationship between the deposition rate, the composition of coatings, and the corresponding ligand parameters are obtained. Recommendations for the selection of the ligand composition of solutions for the chemical deposition of nickel–phosphorus alloy are proposed.

The results of the theoretical and experimental studies of the electric wind velocity and efficiency are considered. The experiments are carried out in air at atmospheric pressure using the electrode system as a flat multispike electrode–two parallel tube.

The impact of the presence of the near-surface graded-gap layers with an increased content of CdTe on the admittance of MIS structures based on MBE-grown n-Hg1–xCdxTe (x = 0.22–0.23) with the Al2O3 insulating coating has been experimentally studied. It has been shown that the structures with a gradedgap layer are characterized by a deeper and wider capacitance dip in the low-frequency capacitance–voltage (CV) characteristic and by higher values of the differential resistance of the space-charge region than the structures without such a layer. It has been found that the main features of the hysteresis of capacitance dependences typical of the graded-gap structures with SiO2/Si3N4 are also characteristic of the MIS structures with the Al2O3 insulator. The factors that cause an increase in the CV characteristic hysteresis upon formation of the graded-gap layer in structures with SiO2/Si3N4 or Al2O3 are still debatable, although it may be assumed that oxygen plays a certain role in formation of this hysteresis.

The requirements imposed on vertical-cavity surface-emitting lasers in a number of metrological problems in which optical pumping of alkali atoms is used are considered. For lasers produced by different manufacturers, these requirements are compared with the experimentally observed spectral characteristics at a constant pump current and in the microwave modulation mode. It is shown that a comparatively small number of lasers in the microwave modulation mode make it possible to obtain the spectrum required for atomic clocks based on the coherent population-trapping effect.

In a temperature range of 9–200 K, temperature dependences of the differential resistance of space-charge region in the strong inversion mode are experimentally studied for MIS structures based on CdxHg1–xTe (x = 0.22–0.40) grown by molecular-beam epitaxy. The effect of various parameters of structures: the working layer composition, the type of a substrate, the type of insulator coating, and the presence of a near-surface graded-gap layer on the value of the product of differential resistance by the area is studied. It is shown that the values of the product RSCRA for MIS structures based on n-CdHgTe grown on a Si(013) substrate are smaller than those for structures based on the material grown on a GaAs(013) substrate. The values of the product RSCRA for MIS structures based on p-CdHgTe grown on a Si(013) substrate are comparable with the value of the analogous parameter for MIS structures based on p-CdHgTe grown on a GaAs(013) substrate.

A new technological process for the synthesis of composite materials based on carbon fibers and the combination of a thermoset and a thermoplastic matrix is described. The mechanical characteristics of a two-matrix composite are presented. The scope of its application is discussed.

The group chemical composition of oil fractions refined at Kinef Ltd. is shown to change with time. The oxidation rate and penetration index of asphalt obtained from heavy residual increase as the penetration increases. The extensibility of road asphalt decreases markedly as the paraffin content increases. Road asphalt meeting PNST 1-2012 specifications was produced by compounding asphalts oxidized to different degrees.

Metal–insulator–semiconductor structures based on n -Hg 1− x Cd x Te ( x = 0.19–0.25) were grown by molecular-beam epitaxy on the GaAs (0 1 3) substrates. Near-surface graded-gap layers with high CdTe content were formed on both sides of the epitaxial HgCdTe. Admittance of these structures was studied experimentally in a wide temperature range (8–150) K. It is shown that an increase in the composition of the working layer and a decrease in temperature lead to a decrease in the frequency of transition to high-frequency behavior of the capacitance–voltage characteristics. The differential resistance of space charge region in the strong inversion increases with the composition of the working layer and for x = 0.22 and 0.25, the differential resistance is limited by the Shockley-Read generation. The values of the differential resistance of space charge region at different frequencies and temperatures were found.

The characteristics of SWIR (1.6–3 μm) 320 × 256 and 1024 × 1024 focal plane arrays (FPA’s) based on n-type In-doped HgCdTe heteroepitaxial layers are reported. The HgCdTe layers were grown by molecular beam epitaxy on silicon substrates with ZnTe and CdTe buffer layers. p–n junctions were formed by arsenic ion implantation into HgCdTe film. Reverse current in the temperature range from 210 to 330 K was found to be limited by the diffusion mechanism. At the same time in the temperature range from 140 to 210 K the reverse current was dominated by the thermal generation of charge carriers through deep traps located in the middle of the band gap. At 170 K NETD was less than 40 mK.

Total conductance of MIS structures based on graded-gap p-Hg1–хCdхTe (x =0.22–0.23) grown by molecular beam epitaxy (MBE) is studied in a wide temperature range 8-300 K. It is found that for MIS structures based on graded-gap MBE p-Hg1–хCdхTe (x =0.23) doped with As to a concentration of 1017 сm–3, the differential resistance of space charge region in the temperature range 8–100 K is limited by the processes of tunnel generation of minority carriers. It is shown that for MIS structures based on graded-gap MBE p-Hg1–хCdхTe (x =0.22) with the hole concentration of (8–9)·1015 сm–3, the differential resistance of space charge region in the temperature range 30–90 K is limited by the processes of Shockley-Read generation, regardless of the presence of a graded-gap layer. At higher temperatures, the differential resistance of space-charge region is limited by processes of the minority carrier diffusion from the quasi-neutral bulk region.

3 Admittance of MIS structures based on graded-gap n-Hg1-хCdхTe (x = 0.31-0.32) grown by molecular beam epitaxy (MBE) is investigated in a wide temperature range (8-300 K). It is shown that the temperature and frequency dependences of the differential resistance of space charge region for structures with a graded-gap layer are qualitatively similar to those for structures without a graded-gap layer. It is found that for MIS structures based on MBE n-Hg1-хCdхTe (x = 0.31-0.32), regardless of the presence of a graded-gap layer, the differential resistance of space charge region is limited by the processes of Shockley-Read generation in the temperature range of 25-100 K.

Total conductance of MIS structures based on heteroepitaxial n-Hg1–xCdxTe (x = 0.23) grown by molecular beam epitaxy has been studied in the temperature range 8–150 K at frequencies of alternating test signal 2 kHz – 2 MHz. It is found that for structures with a near-surface graded-gap layer and an increased content of CdTe, the differential resistance of space charge region increases significantly, as the temperature decreases from 77 to 8 K, and for structures without a graded-gap layer, the changes in the differential resistance of space charge region are nonmonotonic and relatively small. These results can be explained by the fact that at 8–77 K, for structures without graded-gap layers, the differential resistance of the space charge region is limited by tunneling via deep levels, and for structures with graded-gap layers, it is limited by the Shockley-Read generation processes.

Modulation characteristics of absorption at the resonance D 1 line of cesium atoms in a cell with antirelaxation coating are studied. It is experimentally shown that the minimum of the response to harmonic modulation in a certain frequency band coincides with Maxwellian velocity distribution maximum, despite the line profile distortion observed during linear frequency scanning [1]. The effect is theoretically explained.

This paper gives the parameters of 320 × 256 element long-wavelength infrared photodetectors fabricated by a new improved technology based on heteroepitaxial mercury-cadmium-tellur structures. In these photodetectors, the variation of the photodiode bias voltage over the area of the array is minimized; inefficient photodiode regions related to both hybridization and spike-shaped growth defects of epitaxial films are eliminated; the current-voltage characteristics of the diodes in the resulting photodetectors are homogeneous and are limited by the diffusion current component up to −400 mV. The dark current is 0.25–0.45 nA, and R 0 A = (0.6–3) · 102 Ω · cm2. The voltage sensitivity, the threshold irradiance, and the average NETD at the maximum sensitivity are 11.8 · 108 V/W, 3.7 · 10−8 W/cm2, and 26.8 mK, respectively. The percentage of defective elements is 1.5%.

We study the peculiarities of the absorption spectra in D1,2-lines of Cs, caused by optical pumping in cells with antirelaxation coating. In these cells the internal state of the atom, which arose under optical pumping by a monochromatic laser field, is preserved with a high probability in a collision with the wall. As a result, the optical pumping action extends to the entire volume of the cell and to all the velocities of the atoms. This leads to the speed-dependent scanning distortions of the absorption line profile. The detected features should be considered when using laserpumped quantum magnetometers with antirelaxation-coated cells.

Results of the research aimed at improving the strength of hybrid photodetectors (PD) based on mercury-cadmium-telluride heteroepitaxial layers are presented. It is shown that annealing of silicon multiplexers at 157 °C in a hydrogen flow in vacuum changes the shape of indium bumps to hemispherical and levels off their mechanical properties over the plate. Controlled recovery of the natural curvature of silicon multiplexer plates and photosensitive element arrays in hybrid photodetectors at 120 °C extends their operation time. A sequence of technological operations on PD hybridization providing an increase in the efforts needed for separating photosensitive elements from silicon multiplexers at least by 75% compared to the PD with fused indium bumps is proposed.

The dependences of photo-emf of metal-insular-semiconductor structures based on n-Hg1–xCdxTe (x = 0.21–0.23) on bias voltage, frequency, and temperature are experimentally studied. The photoelectrical characteristics of the metal-insulator-semiconductor structures based on epitaxial n-Hg1–xCdxTe (x = 0.21–0.23), including those taking into account the presence of near-surface graded-gap layers having an increased content of CdTe at various temperatures are calculated. The calculated dependences are compared with experiment and it is shown that the differential resistance of the spatial charge region for the metal-insulatorsemiconductor structures based on n-Hg1–xCdxTe (x = 0.21–0.23) without a graded-gap layer is restricted by tunneling through deep levels, whereas the differential resistance of the same structures with graded-gap layers – by the charge-carrier diffusion.

Production of hollow fibres is a promising technology for creating membrane materials with controllable properties. The major factors affecting the structure of hollow fibre are viscosity of the polymer solution, its concentration, and conditions of its casting and post-treatment. The viscosity of the spinning solution is shown to have an effect on the formation of porous structure and its evolution in the post-treatment process. The obtained polyamide-imide based fibres exhibited gas-separating properties at the level of their commercial analogs.

The elastic properties of polymer networks formed via the radical polymerization of macromonomers with two polymerizable end groups are studied via computer simulation. It is shown that variation in the average functionality of network junctions, favg, in a wide range (∼5–55) leads to a significant change in the shear modulus of the network. According to experiments with real networks (gels of poly(ethylene oxide) macromonomers), the shear modulus increases as favg increases. This effect is not due only to a decrease in the fluctuations of positions of network junctions. The main cause of the increase in the modulus is that the modulus component due to interaction between polymer chains (entanglements) increases as the functionality of junctions in the investigated networks increases. The conclusion is made that these networks gain entanglements during the formation of network junctions with high functionality rather than inherit them from the solution of macromonomer chains.

Experiments on open transitions of the D1 line of alkali metals (Cs and Rb isotopes) reveal the dual structure of saturated absorption resonance in the signal of a high-intensity optical wave in the presence of a low-intensity counterpropagating wave. Theoretical analysis shows that the observed shape of the resonance is associated with the openness of the atomic transition as well as with the Doppler effect for atoms in a gas. The results are of general physical significance for nonlinear spectroscopy and can also find application in metrology (frequency and time standards on open transitions).

The classical problem of stability of a thin elastic cylindrical shell loaded by axial compressions forces is considered. The axially symmetric and non-axisymmetric buckling modes of isotropic and orthotropic shells are studied. In contrast to the traditional approach, the well-known expressions for the critical load are obtained by analyzing the equations for the shell behavior and are independent of the boundary conditions.

Capacitance-voltage characteristics of MIS structures based on graded band-gap heteroepitaxial HgCdTe (x = 0.22–0.23 and 0.32–0.36) with grown in situ CdTe as a passivating coating are examined. The average surface-state densities as well as mobile- and fixed-charge densities are determined for the HgCdTe/CdTe, HgCdTe/CdTe–SiO2–Si3N4, and HgCdTe/CdTe–ZnTe systems. It is shown that grown in situ CdTe forms a fairly qualitative interface, and deposition of additional SiO2–Si3N4 and ZnTe layers makes it possible to control the electric strength and charges in the dielectric used.

Short-cavity diode lasers (SCDLs) emitting at the 894-nm D1 line of caesium are developed. Low threshold currents and power consumption will make it possible to use these lasers in chip-size atomic clocks (CSACs) and magnetometers. The SCDL parameters are comparable with the parameters of surface-emitting lasers.

The process of reconstuction of the distribution profile of hole concentration in the p +–n structure by the method of differential Hall measurements upon implantation of ions As+ (Е = 190 keV, D = 3.1014 cm-2, j = 0.025 μA/cm2) into epitaxial films Cd x Hg1–x Te for x ~ 0.2, with the initial electron concentration and mobility n = 1014 cm-3 and μ = 2∙105 cm2∙V–1∙s–1 is numerically simulated. The dependences of degree of reconstruction of the hole-concentration distribution profile on the depth of a shunting n-layer and magnitude of the magnetic field, at which the electrophysical parameters of the p +–n structure are measured, are calculated. The dependence of the limiting magnetic field determining the magnetic-field range for measurements on the n-layer depth is found. It is shown that in calculations one should use the conduction values measured at the same magnetic fields as the Hall coefficients for determination of the holeconcentration distribution profile using the Petritz model.

Capacitance-voltage characteristics of the structure In-SiO2-(graded-gap layer Cd0.71–0.27Hg0.29–0.73Te)-p-Cd0.27Hg0.73Te-GaAs are investigated at temperatures of 80 K and higher. The characteristics have the hysteresis, specifically, the characteristic is similar to a forward portion of the usual high-frequency characteristic (from enrichment to inversion), while the reverse portion has an extended plateau, in which the capacitance of the space-charge region is larger by a factor of approximately 2. To interpret the capacitance-voltage characteristic, the effect of partial screening of the graded-gap part of the space-charge region from the electric field of the test signal, as well as the effect of formation of the potential electron well near the surface due to the recharging of donor levels are considered.

Voltage, frequency, and temperature dependences of photo-emf are experimentally studied in the MIS HgCdTe/SiO 2 /Si 3 N 4 and HgCdTe/AOF structures. The MIS structures were produced on the basis of graded-bandgap Hg 1−x Cd x Te films grown by molecular-beam epitaxy on GaAs substrates. It is found that the subsurface graded-band-gap layers do affect the photoelectrical characteristics of MIS structures. The mechanisms limiting the differential resistance in the space-charge region at various temperatures are revealed.

Networks with different junction functionalities as obtained by polymerization of a macromonomer (composed of 20 units) at identical concentrations were studied by computer simulation. The functionality determined by the length of chains produced from the end units of the macromonomer was varied over a wide range by varying the kinetic parameters of polymerization. From the number of collisions of units with the lattice walls at different swelling stages, the network swelling pressure and the osmotic pressure of solution of its fragments obtained by cutting in half interjunction chains were determined. From these data, the osmotic and elastic components of swelling pressure were found, the former was defined as the pressure of solution and the latter was defined as the difference of the network and solution pressures. The osmotic component is a power function of the polymer concentration with the power index increasing from 2.7 to 3.9 with an increase in functionality from 4.8 to 55 in accordance with a change in network topology. The elastic pressure depends on the swelling ratio Q in different manners at a low and a high functionality of junctions. Its absolute value decreases with a growth in Q in the former case, in agreement with the theory of elasticity of phantom networks (∼Q −1/3), but increases in the latter case. This behavior is consistent with the effect of functionality on the elastic behavior of real polymacromonomer networks and confirms that differences in the character of change in the modulus of such networks during swelling are due to a difference in the functionality of their junctions. Possible mechanisms of the influence of multifunctional junctions on the elasticity of polymer networks are discussed.

The first results on the formation of n+-p photodiodes with a long-wavelength boundary at λ0.5 = 10.6 μm based on p-CdHgTe epilayers with a hole density of 3.3 × 1014 cm−3 are presented. The CdHgTe layers were obtained by molecular beam epitaxy and exhibited p-type conduction in the as-grown state. The hole density and mobility were determined by means of the mobility spectrum technique. The photodiode structures were prepared by B+ ion implantation into as-grown p-CdHgTe epilayers without additional annealing. The R0A product for the n+-p photodiodes obtained is about 20 Θ cm2 at 77 K.

Basic methods and facilities for the external cleaning of the heating surfaces of boilers designed for the combustion of low-grade solid fuels are discussed. Water and steam blastings, which are the basic means of cleaning furnace shields, and semi-radiative and convective heating surfaces have the greatest range of application.

The voltage dependence of photo-emf in the HgCdTe/SiO 2 /Si 3 N 4 and HgCdTe/AOF MIS structures is experimentally studied. The heteroepitaxial graded-band films Hg 0.78 Cd 0.22 Te were produced on the GaAs substrates by molecular-beam epitaxy. It was found that the type of field dependence of photo-emf is related to the conduction type of the semiconductor used and to the presence of near-surface graded-band layers.

A system is developed which allows one to stabilise the diode laser frequency at any point in the vicinity of the cyclic D2-line transition in Rb in the interval from +40 to -150 MHz and to switch the laser frequency within this interval for ~1 ms. A method is proposed and realised for increasing the contrast of the reference sub-Doppler resonance observed in circularly polarised fields. The ultimate contrast of the resonance is estimated. This system can be used to study the anomalous light pressure force acting on atoms in an optical molasses. A magnetooptical trap for Rb atoms is described.

A possibility of application of semiconductor lasers of the visible range as exciting sources for Raman spectroscopy is studied. An experimental set-up for measuring Raman spectra of polycrystalline dielectrics and broad-gap semiconductors excited by a semiconductor laser with a wavelength of 640 nm was created. The conditions under which the spectral width of the lasing line of a semiconductor laser was within 10-3 cm-1 in the continuous mode with a power of 10 mW are realized. The characteristics of various types of exciting sources used in Raman spectroscopy are compared. The results of studies of the characteristic Raman spectra excited with a semiconductor laser in polycrystalline sulfur are presented.

The study of the photosensitivity of an In-SiO2-Cd0.28Hg0.72Te metal-insulator-semiconductor structure with an opaque electrode is continued and the results are reported in this paper. The effect of a drastic decrease in photosensitivity with increasing inversion voltage is considered. This effect manifests itself both under unmodulated illumination (measurements of photocapacitance) and under modulated illumination (measurements of photovoltage), with the onset of a decrease in photovoltage coming ahead of that in photocapacitance. It is believed that this effect is caused by an increase in the longitudinal resistance of the inversion layer and by the anomalous generation of charge carriers at the semiconductor-insulator interface; as a result of the latter, the resistance of the induced p-n junction decreases.

It is demonstrated for the first time that high-performance scanning infrared (IR) focal plane assemblies of the 288 × 4 format for long-wavelength (8–12 μm) IR spectral range can be created based on a CdxHg1 − xTe/Si(310) heterostructure.

A technology has been elaborated and photodetector modules based on Hg1−x CdxTe/GaAs heterostructures and GaAs/AlGaAs multiquantum-well structures grown by molecular-beam epitaxy were fabricated for the 3–5 and 8–12 µm spectral ranges. The photosensitive HgCdTe layers were grown on the GaAs substrates with the intermediate buffer layer of CdZnTe. To decrease the surface effect on the recombination processes, the graded-gap Hg1−x CdxTe layers with x increasing towards the surface were grown. A silicon multiplexer was designed and fabricated by CMOS/CCD technology with a frame rate of 50 Hz. The hybrid microassembly of the photodetector array and the multiplexer was produced by group cold welding on indium columns while monitoring the connection process. The fabricated 128×128 modules based on HgCdTe layers with the cutoff wavelengths 6 and 8.7 µm had a temperature resolution of 0.02 K and 0.032 K, respectively, at a temperature of 78 K and a frame rate of 50 Hz. The photosensitive GaAs/AlGaAs multilayer quantum well structures were fabricated by MBE. It is shown that the technology developed allows 128×128 multielement photodetector arrays (λpeak=8 µm) to be produced with a temperature resolution of 0.021 K and 0.06 K at operating temperatures of 54 K and 65 K, respectively.

The characteristics of the photodiodes based on CdxHg1−xTe solid solutions with graded gap layers were calculated in the context of a one-dimensional diffusion-drift model. The parameters of the photodiodes were shown to be improved when the p-n junction was located in the near-surface graded gap region rather than in the central homogeneous section of the structure. The photodiodes with the n-type layer adjacent to the substrate were found to offer an advantage over the diodes with the p-layer close to the substrate in the case of illumination from the substrate side.

This paper is the continuation of the analysis of a method of determining the cutoff wavelength λc of infrared photodetectors by irradiating the sample with radiation from two blackbodies with different temperatures. The emitters can operate at lower temperatures as the cutoff wavelength λc is increased. The parameters of a system employing two blackbodies, which are placed inside a liquid-nitrogen cryostat and have temperatures of 260 and 320 K, respectively, are presented. It is shown that an error of 1 K in determining the lower or higher temperature produces an error of approximately 0.3 and 0.2 µm, respectively, in λc if λc=10 µm. Measurements on photodiodes fabricated on the basis of Cd0.24Hg0.76Te (λc=8.1 µm) epitaxial layers showed that the difference in the values of λc obtained by this method and from spectral measurements is no more than several tenths of a micron. It is suggested that this method be used as a standard method.

The Hall effect in polycrystalline barium-substituted lanthanum manganite La0.67Ba0.33MnO3 has been investigated in the temperature interval 298

This paper reports on the realization of small area long-wavelength infrared (LWIR) photodiodes based on CdHgTe films grown by molecular beam epitaxy (MBE). The composition of the ternary compound is controlled in situ by a single-wave ellipsometer that offers the possibility to grow epilayers with a desirable composition profile across the film thickness. Photodiodes have a vertical configuration and have been fabricated using planar technology by annealing under an anodic oxide film.

All-round studies of heteroepitaxial HgCdTe nanostructures (NS) growth on GaAs and Si substrates by molecular beam epitaxy have been carried out. In case of Si substrate HgCdTe NS's is very perspectives for IR detectors because of equal thermal expention coefficient with silicon read-out circuits. The problems of HgCdTe conjugations with Si at epitaxy connected with large differences in lattice mismatch and differences in chemical bonding that leads to antiphased domains. We found that the precise formation of transition layer (2 nm in thickness between Si substrates and first ZnTe buffer layer leads to growth HgCdTe NS's without antiphrasis domains. V-defects and etch pits densities are equal to 103 cm−2 and 107 cm−2 respectively. The HgCdTe/Si were used for fabrication photovoltaic 640×512 MWIR focal plane arrays. The operability for λ1/2 = 4.2 μm (77K) was over 97%. The response (Sv) and NETD were as 1,5 × 109 V/W and less 20 mK respectively. We developed the precise growth of symmetric and antisymmetric HgTe QW. We found the following effects: the presence 2D electron gas with high mobilities over 5×105 cm/V×s in doped HgTe QW, the presence @D holes and electrons in undoped HgTe QW and high sensitivity to linear and circular polarized IR and THz radiation in 6 – 400 μm region.

This paper proposes a photodetector design based on a CdHgTe variband heteroepitaxial structure with a high-conductivity layer (HCL) that ensures that the photodiodes have low series resistance and simultaneously serves the function of a short-wavelength cutoff filter. Based on an analysis of how the parameters of the HCL affect the quantum efficiency and the noise-equivalent temperature difference of the photodetector arrays (PDAs), its optimum parameters are determined. Samples of PDAs are fabricated with a format of 320×256 elements for the 8-12-μm spectral range, based on hybrid assembly of photosensitive elements made from p-type (013) HgCdTe/CdTe/ZnTe/GaAs heteroepitaxial structures with an HCL and a silicon multiplexer. The voltage sensitivity, the threshold irradiance, and the noise-equivalent temperature difference at the maximum sensitivity were 4.1×108V/W, 1.02×10−7W/cm2, and 27mK, respectively.

Infrared n-p-photodiode photodetectors based on a hybrid assembly of photosensitive elements of format 288×4 with a 56×43-μm step, made from mercury-cadmium telluride heteroepitaxial structures obtained by molecular-beam epitaxy, have been developed, fabricated, and investigated for the 8–12-μm spectral range, along with silicon multiplexers with bidirectional scanning and internal time delay and storage of the signal. The 288×4-format linear photodetector has the following mean values of voltage sensitivity, detectivity, and NETD at the maximum sensitivity: (1–3)×108V∕W, (1.5–2.0)×1011cmHz1∕2W−1, and 9mK, respectively. There are no defective channels.

This paper presents a comparison of the dark currents and differential resistance of photodiodes, obtained using p-type cadmium-mercury telluride (CdHgTe) layers doped with boron ions, grown by molecular-beam epitaxy (MBE) and liquid-phase epitaxy (LPE). The volt-ampere responses for diodes on CdHgTe layers with composition x=0.215, grown by MBE and LPE (x≈0.222) are characterized by various saturation currents (reverse bias −0.25V) of 1-2 and 5-10nA, even though the band gap is greater for the latter. In this case, the maximum differential resistance is 4×109 and 5×107Ω for diodes based on MBE and LPE layers, respectively. The experimental data are compared with the calculated values. Numerical modelling showed that, for MBE structures with low biases, the dark current is limited by the diffusion current and by the Shockley-Read-Hall current outside the n-p junction, whereas, in LPE structures, there is a substantial contribution of currents through traps in the depletion region.

This paper discusses the results of investigations of processes for forming monolithic integrated cadmium-mercury telluride (CdHgTe)-based IR arrays and their parameters. The processes for growing CdHgTe heteroepitaxial layers (HELs) by molecular-beam epitaxy (MBE) in the cells of a silicon multiplexer have been studied, as well as for forming an n-p junction and contact compounds. For the selective growth of CdHgTe MBE HELs, regimes have been determined for preparing a silicon surface in dielectric windows with dimensions from 30×30to100×100μm. Selective layers of CdHgTe (8μm)/CdTe(5-7μm)/ZnTe(0.02μm) have been grown on Si (310). Ion implantation of boron into selective p-type layers has been used to form n-p junctions. Measurements showed that the parameter R0A is 1.25×105Ωcm2 for the spectral range 3-5μm. A monolithic linear array of format 1×32, based on a CdHgTe MBE HEL, has been fabricated by growth in the cells of a silicon multiplexer.