Cu films are widely used in electronics for interconnections. In some applications, reliable thin-film connecting elements having high electrical conductivity, mechanical stability and adhesion to a glass substrate are required. In this case the length of the elements amounts to tens of centimetres. In this paper, Cu was used as the basis for the connecting elements. To ensure high adhesion Cr was used as an underlayer. The paper investigates the structure, electrical conductivity, adhesion, defect formation of Cu, Cu-Cr, Cr-Cu-Cr thin-film conductors. As a result of the performed research, the regularities of changes of the film structure, electrical conductivity, adhesion, defect formation depending on the technological process parameters were established. Physical and technological mechanisms determining the observed patterns are considered. The research results are used in the device production technology.

Currently, the main material for the production of solar cells is still silicon. More than 70% of the global production of solar cells are silicon based. For solar-grade silicon production the technologies based on the reduction of silicon from organosilicon compounds are mainly used. These technologies are energy-consuming, highly explosive and unsustainable.

The present paper studies the technology of purification of metallurgical-grade silicon by vacuum-thermal and plasma-chemical treatment of silicon melt under electromagnetic stirring using numerical simulation and compares this technology with the existing ones (silane technologies and Elkem Solar silicon (ESS) production process) in terms of energy consumption, environmental safety and the process scalability.

It is shown that the proposed technology is environmentally safe, scalable and has low power consumption. The final product of this technology is multicrystalline silicon, ready for silicon wafer production.

In this work, we present the results of investigation of the nanoporous material – carbon fabrics, which is used as electrodes in rechargeable energy storage capacitors (ultracapacitors). The impurity composition in the fabrics, the influence of thermal annealing conditions on the impurity concentration is studied. The performed studies resulted in determination of the investigated carbon material structure, determination of impurity composition of carbon material and change of impurity content depending on thermal treatment in vacuum at different temperatures and time intervals. The optimum temperature range for the treatment of carbon fabrics in vacuum that is important for its application in energy storage devices is found.

The influence of deep level defects lateral distribution in active layers of multicrystalline Si-based standard solar cells is investigated. Multicrystalline p-type Si wafers with 156×156 mm dimensions and 200 μm thickness were used for SCs preparation. One type of solar cells with conversion efficiency 20.4% was studied using capacitance voltage characteristics method (C-V) and by current deep level transient spectroscopy (I-DLTS). From various places along the diagonal of solar cell’s substrate with 20.4% efficiency nine pieces with an area ∼20 mm2 were extracted and studied. I-DLTS spectra of the five pieces from solar cell were measured. The features of deep levels defects concentration lateral distribution along the SC’s surface were studied.

It is known that n-Si solar cells have higher efficiency than p-Si solar cells. One of the problems connected with n-Si application for solar cell production is the difficulty of using Czochralski method for growing n-Si ingots, uniform in structure. The present paper examines the possibility of production of n-Si ingots, uniform in resistance, by neutron transmutation doping (NTD) for photovoltaics using the mathematical modeling method. The provided calculation data are obtained by MCU-RFFI/A accounting code with DLC/MCUDAT-1.0 constant library developed by «Kurchatov Institute» Russian Research Center. The MCU accounting code is used for solution of the neutron-transport equation by Monte-Carlo procedure on the basis of estimated nuclear data for arbitrary three-dimensional geometry systems.

The present paper provides the estimation of uniformity of neutron-flux density along the ingot length and radius; dependence of silicon resistance on duration of irradiation. These studies established the neutron flux density distribution along the ingot length and radius; regularities of silicon resistance changes on duration and intensity of irradiation.

Electrodeposition in pulse current mode of nickel-molybdenum alloy on a nickel substrate was studied. The range of current density variation from 2 to 9 A/dm2 was investigated. The range of pulse and pause step lengths is from tens to hundreds of milliseconds. SEM-images of applied coatings surfaces are obtained. The method of energy dispersive spectroscopy determined that the molybdenum content in the coating is 21-24 wt%. It was found that under transient pulse mode of electrolysis, with the pulse step corresponding to hundreds of milliseconds, the most rigid and smooth coatings of the electrolytic nickel-molybdenum alloy are obtained from ammonium-citrate electrolyte. It is shown that the percentage of nickel in the alloy does not depend on the electrolysis mode.

The present paper examines nanoporous material – carbon fabrics, which is used as electrodes in rechargeable energy storage capacitors (ultracapacitors). The fabrics structure, impurities composition, the influence of impurity types on ultracapacitor characteristics and the influence of thermal treatments on the impurities concentration are studied. The analysis of the ultracapacitor equivalent circuit with the studied material is made and the capacitor charge-discharge characteristics are investigated.

The performed studies resulted in determination of the investigated carbon material structure, determination of impurities composition of carbon material and change of impurities content depending on thermal treatment in vacuum. The optimum temperature range for treatment in vacuum is established. The equivalent circuit of the ultracapacitor is analyzed and its charge-discharge characteristics are investigated. The chosen equivalent circuit makes it possible to estimate the influence of pores different size on the ultracapacitor charge-discharge characteristics that is important for its application in energy storage devices.

The electrophysical (donor-acceptor) properties of the of glass carbon (GC) surface before and after its electrochemical modification in conditions of chemisorption of fluorine-containing nanogroups were studied using the methods of scanning probe microscopy. The values of the coefficients characterizing local (for atomic-scale) electrophysical properties of the surface are calculated on the basis of obtained local spectral dependences of the tunneling current on the tunnelling voltage. Fluorination of the GC surface resulted in change of the ratio of its donor-acceptor atomic characteristics, acceleration of electrode processes, and increase of the overall tunneling activity of local places.

The present paper has suggested a new non-observational method to calculate electronic structure of carbynes taking into consideration the influence of the spin-orbital coupling. The method is demonstrated by calculations of the structure splitting at the Fermi level in cumulene and polyyne carbynes having semiconductor and metallic electronic structure correspondingly. These couplings result in 2 - 3 meV gaps.

The paper presents the research results of formation features of nanoporous titanium oxide structure under electrochemical anodizing by AC-DC current. It is shown that addition of current AC-component (at the frequency of 100 Hz – 10 kHz) leads to increase of the coating formation rate and to structure quality changes of nanoporous TiO2 coatings: open intertubular space appears, intertubular bridges are formed and the nanotubes section form becomes round.

The paper presents the research results of influence of various parameters of magnetic field concentrator geometry on sensitivity of magnetically controlled MEMS switches. It is shown that magnetic sensitivity increases with the growth of the magnetic concentrator width and practically does not depend on its length. It is established that dependence of magnetic sensitivity on the overlap length of the ferromagnetic flexible contact-concentrator has a minimum corresponding to 2-3 lengths of the contact gap. Recommendations on sensitivity increase of magnetically controlled MEMS switches are provided.

The present paper contains results of the experimental researches of structure properties of the catalytic coating based on the nanoporous TiO2 film affected by corona-discharge plasma in air atmosphere under atmospheric pressure in the test system of needle-plane electrodes. Coating of the plate electrode was found to influence insignificantly on the discharge current-voltage characteristic, however if there is a coating on the plane electrode surface, an offset is observed towards lower currents under constant voltage at the gap. Obtained data on the surface morphology change shows that under negative corona erosion of the nanoporous TiO2 coating surface is practically absent and under positive corona, decrease of the coating thickness is observed.

The influence of deep level defects (DLs) on the conversion efficiency of multicrystalline Si-based standard solar cells (SCs) is investigated. Multicrystalline p-type Si wafers with 156×156 mm dimensions and 200 μm thickness were used for SCs preparation. Three types of SCs with conversion efficiency 10%, 16.8% and 20.4% were studied using capacitance voltage characteristics method (C-V) and by current deep level transient spectroscopy (I-DLTS). The correlation between the total concentration of DLs and the values of the SCs conversion efficiency is found.

The paper presents the research results of formation peculiarities of barrier electrically insulated coatings based on titanium oxide (TiO2) under conditions of AC-DC electrochemical anodizing. It is shown that overlapping of AC component (at the frequency of 100 kHz – 10 MHz) leads to formation of coatings 1.2-1.4 times thicker. Dependences of the coating thickness on frequency under various ratios of the AC-component amplitude to the DC-component of anodizing voltage have been obtained.

The paper presents the results of numerical modeling of thermomechanical stresses and thermal fields for conditions of erosion-resistant electrode coatings of vacuum and gas discharge switching devices with W-Ti-Cu and W-Mo-Cu structures at local temperature and electric current influence in axially symmetrical approximation. The efficiency assessment of intermediate layers introduction by comparison of interlaminar mechanical stresses is carried out. It is shown that introduction of titanium interlayer in the coating with W Cu structure results in considerable (more than two times) decrease of internal thermomechanical stresses between layers that increases coating resistance to delamination. The optimum value of interlayer thickness at which the minimum thermomechanical stresses are provided is determined.

The paper presents complex research of the structure and electrophysical properties of thin films on the basis of Cr2O3, V2O5 and SiO2 oxides compounds. The paper studies binary compounds films of Cr2O3 -V2O5 and Cr2O3 - V2O5 -SiO2 films. The method of electron-beam evaporation is used for the films deposition; glass is used as the substrate. The films structure is studied by the methods of slow electron diffraction, infrared spectroscopy, and electron paramagnetic resonance. The films composition is determined by the X-ray microanalysis.

In the course of studies the following regularities have been established:

- dependence of the films structure on their composition;

- dependence of electrophysical films properties on the their composition;

- dependence of volt-ampere characteristics on the films composition (memory effect);

- high film stability to the effect of electron flow and radiation in the discharge plasma.

The paper presents the results of numerical modeling of thermomechanical stresses and thermal fields for conditions of erosion-resistant electrode coatings of magnetically controlled MEMS switches with W-Ti-Cu structure at local temperature and electric current influence in axially symmetrical approximation. It is shown that the introduction of titan interlayer (30-100 nm) in the coating with W-Ti-Cu structure results in considerable (more than two times) decrease of internal thermomechanical stresses between layers that increases coating resistance to delamination. It is established that there is an optimum value of Ti layer thickness at which the minimum thermomechanical stresses are provided.

Creation of high efficiency and safe air purification systems is the important task caused by their wide use in living quarters, medical institutions, industrial areas. The most effective cleaning systems are the ozone based ones which is formed as the result of the corona or barrier discharge. The main disadvantage of these purification systems is high concentration of ozone in discharge air. The paper concentrates on the study of catalytically active coatings on the basis of titanium dioxide for effective destruction of ozone inside air purification systems. It is shown that use of catalytically active coatings of collecting electrodes on the basis of titanium dioxide and manganese oxide allows to decrease significantly (20-50%) the ozone concentration at the filter exit. As the results of the researches the following requirements have been determined: -

Currently the improvement of stand-alone PV power systems characteristics, including increase of their service life is the actual direction of ground solar power development. The analysis of stand-alone PV power systems efficiency with the use of ultra capacitors is carried out by the means of mathematical modeling. The obtained data shows that the use of ultra capacitors as additional short-term energy storage devices in stand-alone PV power systems contributes to considerable increase of storage batteries lifetime and the total system operating time.

The paper reports the tests results of ruthenium contacts coatings of magnetically controlled MEMS switches. During the tests the contact resistance was measured and the lifetime of MEMS switches was evaluated. After testing the analysis of the form and contact surface structure using SEM-method was carried out. The experiment results showed that the application of ruthenium nanolayers as the contact coating at slight increase of the contact resistance improves the lifetime of MEMS switches considerably.

Nowadays the increase of the lifetime of all MEMS switch types (RF MEMS relays, magnetically controlled on-off MEMS switches) is the most actual problem. The work resource and operating characteristics, first of all, contact resistance, of any switching unit, the basis of the construction of which is a dry contact, are determined by the contact coating properties. This is true for MEMS switches too.

The paper presents the results of the study of the operating characteristics of magnetically controlled MEMS switches with ruthenium and gold contact coatings of up to 100 nm thickness. During tests the following switching mode was used: switching voltage – 3 V, current - 10 μA. Each MEMS switch was subjected to 100 million cycles switching at the frequency of 100 Hz. After testing the contact surface investigation by SEM-method and electrical characteristics measurement was carried out. The paper presents SEM-images of the contacts surface and statistical date of electrical characteristics.

After 100 million switching cycles MEMS switches with nanoscale ruthenium coating have shown 100% operating capacity; 16% of switches with gold contacts turned out to be inoperative due to electrical contacts sticking.

The results of researches by SEM-method show that the contacts without nanoscale coating have the traces of strong erosion and melting; the contacts with nanoscale ruthenium coating practically did not change the form and flatness.

So, the test results indicate that nanoscale ruthenium coatings of the electrical contacts provide excellent resource for the switches operation of hundred millions and more cycles.