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We report an experimental study of the electrical properties of the interface between the Al2O3 passivating coating grown by plasma enhanced atomic layer deposition at different temperatures and the p-CdHgTe (xCdTe = 0.22) coating grown by molecular beam epitaxy via measuring the C–V characteristics of MIS structures. It has been established that, at an Al2O3 growth temperature of 200°C, the concentration of acceptors in CdHgTe increases due to dissociation and, at a temperature of 80°C, the spread of the insulator capacitance and built-in charge increases. The optimum temperature for growing the passivating Al2O3 coating on CdHgTe lies in the range of 120–160°C.

The possibility of local measurement of the fluctuation level of the radial plasma velocity using equatorial enhanced scattering of a narrow microwave beam in the upper hybrid resonance in internal regions of tokamak plasma is demonstrated. Restrictions of the proposed method at the plasma periphery where the density fluctuation amplitude increases and small-angle scattering of microwaves by the fluctuations along the path to the upper hybrid resonance and back becomes significant are clarified.

The C–V characteristics of Au/Al2O3/In0.52Al0.48As and Au/SiO2/In0.52Al0.48As metal–insulator–semiconductor structures have been studied. It has been established that the fragmentary measurement of the C–V characteristics of InAlAs-based metal–insulator–semiconductor structures, in contrast standard registration method to at a constant voltage sweep rate, significantly weakens the effect of the hysteresis phenomena and allows one to record stationary curves. It is shown that the density of fast interface states calculated by the Terman method from such C–V characteristics slightly changes over the InAlAs band gap and amounts to (3–6) × 1011 and (1–3) × 1011 eV–1 cm–2 for MIS structures with Al2O3 and SiO2, respectively.

The results of experimental studies on the breakdown of noble gases (argon and krypton) by terahertz radiation from the Novosibirsk free electron laser (NovoFEL) are presented. For the first time, the breakdown thresholds of noble gases by terahertz radiation were measured in a wide pressure range (0.2-1.5 bar). Previous experiments to measure breakdown thresholds in the THz range in various gases were carried out for hundreds of GHz or at atmospheric pressure. Experimental breakdown thresholds are compared with calculated data using various simplified models. Keywords: THz radiation, gas breakdown, THz laser discharge.

Polarizability and absorption cross section of metal (Ag, Au, Cu, and Na) nanoparticles in glass far from the plasmon resonance, within the spectral interval of 1–1.6 μm, are simulated numerically. By the example of Ag nanoparticles, it is shown that the absorption cross section of nanoparticles in the telecommunication wavelength range decreases by 103 times as compared to the corresponding value in the region of the plasmon resonance. At the same time, polarizability decreases by only ten times. Polarizabilities of nanoparticles made of the abovementioned materials and having different geometry are compared. The use of metal nanoparticles is shown to be promising for creating electrooptical glasses.

—The effect of low-dose γ radiation on the mechanisms of low-frequency conductivity of mesoporous silicon has been studied. It has been shown that γ irradiation preserves the hopping character of conductivity at a change of the frequency of phonon lattice vibrations, a decrease in the size of the hop, and a shift of the level of the capture of traps to the Fermi level in the band gap, which makes the structure with mesoporous silicon irradiated by γ radiation promising for the creation of multifunctional resistive and capacitive devices.

The interface between Cd0.22Hg0.78Te and HfO2 grown by plasma-enhanced atomic layer deposition at a temperature of 120oC in a specifically optimized deposition mode has been studied. The method used in this work for measuring the admittance of metal-dielectric-semiconductor structures made it possible to establish that their electrophysical parameters are uniform over the sample surface. The spectrum of fast surface states density at the HfO2-Cd0.22Hg0.78Te interface has been calculated. Keywords: CdHgTe, HfO2, ALD, C-V, passivating coating.

The surface of metals after irradiation by intense streams of argon plasma arising in the plasma focus was studied. Metal samples of steel, copper, tungsten and molybdenum were investigated. Different types of microstructures were recorded. The surfaces of steel samples contain micropores with sizes of 0.1-3 μm with a shape close to circular. On copper and tungsten plates the appearance of fine-dispersed structures with sizes of 0.5-20 μm is observed. The possible mechanisms of the appearance of these microstructures are discussed. Keywords: plasma focus, intense plasma flows, micropores, filamentous discharge structure.

We have measured the density of plasma (electron concentration) in discharge maintained in inhomogeneous argon flow under the action of high-power pulsed radiation of gyrotron (frequency, 0.67 THz; power 40 kW; pulse duration, 20–30 μs) in a range of background gas pressures in the discharge chamber from 10–3 to 300 Torr. The electron concentration at low pressures (10–3 to 7 Torr) was determined using Starkeffect induced broadening of the Hα atomic emission line (656.3 nm) of hydrogen present in discharge as a small impurity in residual gases. The maximum observed Stark broadening of the Hα line corresponded to a plasma density on the order of 2 × 1016 cm–3, which exceeded the critical value for the given frequency of radiation sustaining the discharge. At background pressures above 7 Torr, the plasma density was estimated from analysis of the spatiotemporal patterns and waveforms of discharge glow in the visible spectral range. These estimations gave electron concentrations on the level of (1–2) × 1015 cm–3.

The influence of low doses of γ rays on the capacitive properties of structures based on mesoporous silicon has been investigated. The concentration distribution of dangling charged bonds over the layer depth, which changes under irradiation, has been found using the capacitance–voltage characteristics at different frequencies of the test signal. It is shown that the concentration and relaxation time of surface charged states in a structure with a mesoporous silicon layer decrease under γ irradiation, which makes the material promising for devices with controlled reactance (varactors) that are resistant to γ irradiation.

The effect of low exposure doses (5–40 kR) of gamma radiation on the electrical properties of structures based on a mesoporous silicon (SiMP) layer is investigated. It is demonstrated that the conductivity of the SiMP layer increases, the Fermi level shifts, and the trap density changes in gamma-irradiated Al/SiMP/p-Si/Al structures. Long-term stable switched-state memory in the region of the I–V curve hysteresis is revealed. This effect is controlled by the irradiation dose.