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The goal of this work is the qualitative and quantitative interpretation of experimental data obtained for the effect of additional boron ion implantation on the temperature dependence of dislocation-related luminescence (D1 line) of self-implanted silicon. This goal is motivated by the need in development of effective light emitter for silicon-based optoelectronics. The model explaining the previously established improvement of the D1 line temperature dependence is suggested and supported by computer calculations based on a set of kinetic equations taking into account the radiative and nonradiative electron transitions between energy levels.

The effect of anticancer antibiotic doxorubicin on structural organization of anionic lipid monolayers has been studied. X-ray reflectivity and grazing incidence diffraction techniques were applied to monitor the changes in 2D structure and electron density distribution of Langmuir monolayer composed of negatively charged dipalmitoylphosphatidylglycerol (DPPG) and dioleoylphosphatidylserine (DOPS). For comparison, monolayer of zwitterionic dipalmitoylphosphatidylethanolamine (DPPE) also was investigated. The presented experimental results suggest that doxorubicin interaction with anionic lipid monolayers (DPPG and DOPS) proceeds preferentially via electrostatic attraction—positively charged amino groups of doxorubicin bind to negatively charged head groups of phospholipid molecules. Based on the obtained data, the penetration of doxorubicin into the hydrophobic part of anionic lipid monolayers does not occur. X-ray measurements on DPPE monolayer indicated that doxorubicin did not cause any significant alterations of molecular packing in condensed monolayer of zwitterionic DPPE molecules.

The formation of oxide semiconductor films of the (Mn,Co,Cu)3O4 type by radio frequency magnetron sputtering is presented. The conditions of deposition and subsequent heat treatment make it possible to obtain films with electrophysical characteristics close to those of the bulk ceramic materials used as a target for magnetron sputtering. Two variants of thermistor geometry were implemented. In the first case, the working layer of oxide semiconductor was deposited directly on the dielectric substrate (planar geometry), and in the second case on the layer with high electrical conductivity (Ni or Al) forming the inner electrode (layered geometry). The lower limit of the nominal resistance of the planar thermistor while maintaining high temperature nonlinearity is ~ 10 kΩ. The layered structure with the inner electrode makes it possible to reduce the lower limit of resistance up to ~ 50 Ω without losing the temperature nonlinearity of the thermistor. In addition, heat treatment above 450 °C or current self-heating with sufficient power output leads to the appearance of a pronounced voltage nonlinearity, which increases the thermal constant B of thermistors from 2400–3400 to 5000–5500 K. The fields of application of oxide-film structures for the correction of linear resistors and the implementation of integration approaches in the construction of linearized sensors are discussed.

The electrophysical characteristics of a multilayer memristive Au/Ta/ZrO2(Y)/TaOx/TiN structure have been studied. Electron and ion electret effects due to charge carrier trapping and ion migration polarization in the dielectric have been discovered. The influence of traps on electroforming processes and resistive switching has been established. The values of activation energy and ion and trap concentrations have been determined. The effect of resistive switching stabilization has been found, which is associated with the specific bilayer structure of TaOx and self-forming tantalum nanoclusters. The nanoclusters serve as electric field concentrators in the course of electroforming and subsequent resistive switching.

An alternative to the currently existing elemental basis for creating dynamic random-access memory and flash memory is memristor structures, i.e., two-electrode systems, whose operation is based on the resistance switching effect. In this paper, the results of studying the specific features of the production of memristor structures on the basis of copper sulfide as a promising material providing high-efficiency performance of the structures are reported. The process of copper sulfurization is considered. In this process, the surface region of the copper layer is transformed into sulfide, and the remaining part of the layer is used as the active electrode for the later formed memristor structure. It is shown that, as the concentrations of the initial chemical reagents is increased, the surface roughness of the sulfide layer significantly increases. The sulfide growth rate at optimal initial concentrations of the chemical reagents is ~30 nm/min. In studies of memristor structures, it is established that, as the copper sulfide thickness is increased, the ratio between the resistances in the low- and high-resistance states increases from 11.2 to 12.5. In the memristor structures formed in the study, the time of switching from the high- to low-resistance state is about 1.3 μs, whereas the time of switching from the low- to high-resistance state is 0.9 μs.

In this paper, the study of the dynamic pyroelectric effect under different powers of modulated heat flux in deuterated triglycine sulfate (DTGS) near the Curie point is presented. It was f...

The peculiarities of resistive switching in capacitors with yttria-stabilized hafnia layers were studied. The characteristics of current transport in the initial state and after electroforming and resistive switching at different temperatures were examined. The parameters of a small-signal equivalent circuit of a capacitor were determined for switching into low- and high-resistance states. These parameters suggest that the resistance of filaments changes after each successive switching. This provides an opportunity to use such measurements to determine the nature of resistive switching and verify the reproducibility of its parameters. The contribution of electron traps to switching was revealed. Ion migration polarization was observed at temperatures above 500 K, and the activation energy of ion migration and the ion concentration were determined. The effect of resistive switching under the influence of temperature was observed and interpreted for the first time.

In this work, a process solution for the formation of an array of piezo- and pyroelectric structures with the use of a matrix of nanoprofiled silica is demonstrated. It is proposed to use plasma etching through a hard mask of porous anodic alumina for the formation of the matrix. Nanoparticles of a ferroelectric copolymer of vinylidene fluoride with trifluoroethylene are formed in the pores of the matrix. The results of measurements of the piezoelectric and pyroelectric responses of this structure are presented.

An approach to formation and training of an artificial neural network (ANN) based on thin-film memristive metal–oxide–metal nanostructures, which exhibit the effect of bipolar resistive switching, has been proposed. An experimental electric circuit of a small-sized ANN (a two-layer perceptron with 32 memristive elements) has been constructed. An algorithm for formation of weighting coefficients (ANN training), which takes into account probable spread of technological parameters of memristive structures has been developed.

The frequency dependence of real (e′) and imaginary (e″) components of the complex dielectric permittivity has been determined for tin-thiohypodiphosphate Sn2P2S6 films in the temperature region from 150 to 400 K. There are two dielectric relaxation regions in the frequency range between 10−1 and 107 Hz. The high-frequency dielectric dispersion region at 103–107 Hz exhibits Debye type behaviour due to a semiconductor-metal interface barrier similar to a Schottky barrier. At low frequencies from 10−1 to 103 Hz, dielectric response is nearly a “flat loss” at least in the low-temperature region. At elevated temperature, the flat dispersion region disappears and a strong linear decrease of e″ (ω) is observed because of the dc conductivity.

In this paper we demonstrate a technological route for the formation of an array of memristor structures using a self-assembly matrix of porous anodic aluminum oxide. We propose using a porous alumina matrix as a solid mask to develop pores in the dense silicon oxide layer below the mask, in which a material characterized by the possibility of resistive switching is formed. The merit of this mask should include reproducibility and the high-precision control of geometric parameters of the pores. The current-voltage characteristics of a memristor structure based on solid electrolyte Cu2S are determined.

The results of a study of film composites based on polyvinylidene fluoride with carbon nanotubes (CNTs) by dielectric relaxation spectroscopy are presented. For composite samples containing more than 0.5 wt % of nanotubes, nonlinear current–voltage characteristics are obtained. The concentration dependences of the electrical conductivity of the composites are examined and the percolation threshold for the samples under study is determined. It is shown that an insignificant increase in the electrical conductivity of the composites is observed even upon filling with 0.2 wt % of CNTs, whereas the electrical conductivity becomes three orders of magnitude higher upon the introduction of 1 wt% of CNTs and is seven orders of magnitude higher at more than 3 wt %, compared with the unfilled polymer. This confirms that CNTs are promising for the development of electrically conducting composites and film materials on the basis of polyvinylidene fluoride.

The preparation method of magnetoelectric multilayered ceramic heterostructures was suggested, and series of the rectangular and disk shape samples were produced on the base of this method. The maximum value of a magnetoelectric voltage coefficient αE = 35 V/(cm × Oe) was observed for the eleven-layered rectangular specimen at the electromechanical resonance frequency fr = 144 kHz, НDC = 84 Oe, and НAC = 2.5 Oe. The sensitivity to static magnetic fields is equal to 3.5 × 10−2 Oe, and the alternating field sensitivity is equal to 8 × 10−3 Oe.

A physical model of synaptically coupled neuron-like generators interacting via a memristive device has been presented. The model simulates the synaptic transmission of pulsed signals between brain neurons. The action on the receiving generator has been performed via a memristive device that demonstrates adaptive behavior. It has been established that the proposed coupling channel provides the forced synchronization with the parameters depending on the memristive device sensitivity. Synchronization modes 1: 1 and 2: 1 have been experimentally observed.

The principles of ion-beam simulation of the effect of fast (fission) neutrons and high-energy protons based on medium-energy ion irradiation have been developed for the Au/Zr/SiO2/TiN/Ti capacitor-like memristive nanostructures demonstrating the repeatable resistive switching phenomenon. By using the Monte-Carlo approach, the irradiation fluences of H+, Si+ and O+ ions at the energy of 150 keV are determined that provide the ionization and displacement damage equivalent to the cases of space protons (15 MeV) and fission neutrons (1 MeV) irradiation. No significant change in the resistive switching parameters is observed under ion irradiation up to the fluences corresponding to the extreme fluence of 1017 cm−2 of space protons or fission neutrons. The high-level radiation tolerance of the memristive nanostructures is experimentally confirmed with the application of 15 MeV proton irradiation and is interpreted as related to the local nature of conducting filaments and high concentration of the initial field-induced defects in oxide film.

The electric response of layered 2-2 connectivity magnetoelectric composites to the action of a modulated heat flow, which is detected by a dynamic method, is studied. The kinetics of the pyroelectric response of the composite material to a pulsed thermal action is calculated. The experimental results and calculation data suggest that a modulated heat action induces a signal due to both the pyroelectric and piezoelectric effects. The latter effect is caused by the mechanical interaction of the layers of lead zirconate titanate ceramic and nickel–zinc (Ni–Zn) ferrite.

Transmission electron-microscopy examination revealed the appearance of a hexagonal silicon (9R polytype) inclusions in the subsrface silicon layer upon ion implantation and subsequent heat treatment of the SiO2/Si structure. The formation of this hexagonal phase is stimulated by mechanical stresses arising in the heterophase system in the course of ion implantation.

Semiconductor quantum dots have attracted tremendous attention owing to their novel electrical and optical properties as a result of their size dependent quantum confinement effects. This provides the advantage of tunable wavelength detection, which is essential to realize spectrally selective photodetectors. We report on the fabrication and characterization of a high performance narrow band ultraviolet photodetector (UV-B) based on Indium oxide (In

GaN nanocrystals were formed in a silicon matrix by sequential implantation of Ga+ and N2+ ions followed by either Furnace Annealing (FA) or Rapid Thermal Annealing (RTA). The formation of Ga-rich clusters and Ga–N bonds was confirmed by X-ray photoelectron and photoluminescence spectroscopy. A Schottky top contact and ohmic bottom contact were fabricated and current–voltage (I–V) characteristics of the implanted samples were studied. Current values were found to be higher in RTA samples and lower in FA samples. It is observed that the height of the Schottky barrier strongly depends on the kind of annealing and is found to be 0.65 ± 0.02 eV for FA and 0.56 ± 0.02 eV for RTA compared to the value of 0.61 ± 0.02 eV for the pristine Si sample. A carrier transport mechanism is discussed based on experimental results for both kinds of annealing.

An approach for the physicochemical modeling of an anodic titanium oxidation process considering electric field distribution, titanium oxidation reaction, and local dissolution of the oxide in electrochemical cell has been suggested. The developed model allows describing the dependence of geometric parameters of the formed titanium oxide on water concentration in the electrolyte. The model was validated using experimental studies.

In this work, pyroelectric properties of composite films on the basis of poly(vinylidene fluoride-trifluoroethylene) copolymer with a various level of ferroelectric ceramics inclusions of barium lead zirconate titanate solid solution were investigated by the dynamic method. The composite films were prepared by the solvent cast method. The unusual spike-like dynamic response with a quasi-stationary component was observed. It is supposed that composite films may be effectively used for pyroelectric applications.

The influence of intrinsic impurities (boron, phosphorus) in the original CZ-Si on the behavior of the D1 dislocation-related luminescence line has been investigated in the samples with dislocations introduced by Si+ ion implantation upon the change of annealing ambient. It is established that, for the phosphorus-doped samples, the D1 line does not occur at the annealing at 1100 °C in inert ambient (N2), but its intensity increases with increasing the oxygen content. For the boron-doped samples, this line arises in the case of annealing in an inert ambient, herewith the intensity practically does not depend on the composition of the annealing ambient. At the annealing in argon ambient at 900-1100 °C, the maximal photoluminescence intensity is achieved for annealing at 900 °C. The results are interpreted in terms of interaction between boron and point defects as radiative recombination centers located in dislocations atmospheres. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The dielectric characteristics of film samples of P(VDF-TrFE) + TGS composite in the frequency range of 103–107 Hz are studied. The values of the real and imaginary parts of the complex dielectric constant in the temperature range of–40 to 140°C, including the points of the polymer matrix’s transition to the glassy state when Tg ≈–25°C and the ferroelectric phase transition. An analysis of the ferroelectric crystal inclusion effect on the dielectric response of P(VDF-TrFE) copolymer matrix is carried out.

A model of radiative and nonradiative transitions in silicon quantum dots is presented, which describes the photoluminescence temperature dependence of the ion-synthesized ensembles of Si nanocrystals in SiO2. A four-level system of transitions is considered that takes into account thermally activated processses and exchange splitting of the ground energy state of exciton in a silicon nanocrystal into triplet and singlet levels, the transfers from which to the ground state are responsible for the luminescence. The temperature dependence of monochromatic photoluminescence components was obtained based on the stationary solution of the system of kinetic equations for the population of levels that satisfactory describes the experimental data. The exciton energy splitting values depending on the energy of emitted photons were found and compared with the data in the literature.

3D Monte-Carlo algorithm and computer code have been developed that allows choosing and optimizing the conditions of ion irradiation needed for the adequate ion-beam simulation of radiation damage under fast neutron irradiation. It is established that, by the proper selection of energy and dose of Si+ ions, it is possible to reproduce well the effect of irradiation with fission neutrons of subsurface and buried layers of silicon or Si-based 2D and 3D-heterostructures. The results can be used for testing the radiation hardness of silicon-based electronic and optoelectronic device structures.

An array of cross-point memristive devices has been implemented on the basis of yttria-stabilized zirconia thin film for applications in prototypes of spiking neural networks. The resistive switching phenomena and the plasticity nature of such memristive devices are studied. Reproducible bipolar resistive switching and precise tuning of resistive state are demonstrated and used to implement the plasticity rule according to STDP (spike-timing-dependent plasticity) mechanism. STDP learning is found to be dependent on the memristor's initial resistive state value and discussed in terms of the finite conductance change in studied structures. Obtained results provide the foundation for autonomous neuromorphic circuits with unsupervised learning development.

Metal-assisted silicon etching in the HF/H2O2/H2O solution with silver ions as a catalyst was investigated. It is found that geometric parameters of layers of nanostructured silicon are determined by the silver-catalyst concentration. A spontaneous stop of the etching process at low Ag+ ion concentration is explained by formation of insoluble Ag2SiO3.

Results obtained in a study of the effect of the activity of fluorine-containing electrolytes on the thickness of an anodic layer of porous titanium dioxide are presented. It is shown that the process of chemical dissolution of the oxide during the course of the formation of porous anodic titanium oxide is affected by the dissociation of fluoride compounds in electrolytes. It is demonstrated that nonaqueous solutions with a water content not exceeding 10% should be used to obtain thick films.

The results obtained in a study of low-temperature methods for the synthesis of nanostructured titanium and zinc oxides are presented. It is shown that layers of porous titanium-oxide and zinc-oxide nanocrystals can be formed in a wide range of geometric parameters by varying the technological characteristics of the anodization process.

A four-level model of photoluminescence from Si nanocrystal arrays embedded in a SiO2 matrix is suggested. The model allows for thermally activated transitions between singlet and triplet levels in the exchange-split energy state of an exciton in an excited silicon nanocrystal. An expression is derived for the temperature dependence of the intensity of photoluminescence monochromatic components. A correlation is found between the amount of splitting and the emitted photon energy by comparing model data with our experimental data for ion-synthesized Si nanocrystals in a SiO2 matrix. The model explains the finiteness of the photoluminescence intensity at temperatures close to 0 K and the nonmonotonicity of the temperature run of the intensity.

Functional capabilities of the scanning electrical-conductivity microscopy (SECM) in determining the electrical conductivity of nano-sized elements, studying the nanostructure of conductive coating materials, and evaluating the conductivity of nano-objects are described. The applicability of the SECM to finding imperfections in the multilevel metallization of integrated circuits with a nano-sized topology is demonstrated.

The possibility of ion beam formation of gold nanoparticles in SiO2 and Al2O3 matrices with presynthesized single-layer and multi-layer ensembles of silicon nanocrystals is revealed by analyzing the spectra of optical transmission. The parameters of gold nanoparticles are estimated. It is shown that luminescent properties of Si nanocrystals are preserved under irradiation with gold ions.

The features of formation of porous alumina masks for silicon nanoprofiling were investigated. The influence of micromorphology on the property of the local etching of silicon on the interface of an anodized double-layer structure of Al-Ti was shown. The correlation between the aspect ratio of alumina pores and the geometrical parameters of the porous silicon was investigated.

Films obtained using molecular-beam deposition of SiO powder on c-Si (111) substrates for the purpose of SiO2 system formation with silicon nanocrystals were investigated before and after 900–1100°C annealing by photoluminescence, ultrasoft X-ray emission spectroscopy, X-ray photoelectron spectroscopy, X-ray absorption near-edge structure spectroscopy, and X-ray diffraction. The appearance of (111)-oriented luminescent silicon nanoclusters in considerable amounts upon annealing at T = 1000–1100°C is established in the investigated films. An anomalous phenomenon of X-ray absorption quantum yield intensity reversal for the L2,3 elementary silicon edge is detected. Models for this phenomenon are suggested.

The specific features of the kinetics of local probe oxidation of ultrathin V, Nb, Ta, Ti, TiN, and W metal films are studied. It is established that the kinetics of the oxidation process depends on such properties of the material to be oxidized as the resistivity, the presence of a natural surface oxide film and its thickness, the relationship between the densities of the metal and oxide, and the electrochemical constant of the oxidation process. For the material that provides a high efficiency of formation of local insulator nanoregions, vanadium is chosen, since this metal exhibits the maximum rate of anodic probe oxidation.

A test structure on the basis of nanoprofiled aluminum to determine the curvature radius of the cantilever tip is described. This structure was tested by studying tips with different geometries. The test structure allows one to determine the tip sharpness geometry with an accuracy of 2 nm.

Luminescent and structural characteristics of SiO2 layers exposed to double implantation by Si+ and C+ ions in order to synthesize nanosized silicon carbide inclusions have been investigated by the photoluminescence, electron spin resonance, transmission electron microscopy, and electron spectroscopy methods. It is shown that the irradiation of SiO2 layers containing preliminary synthesized silicon nanocrystals by carbon ions is accompanied by quenching the nanocrystal-related photoluminescence at 700–750 nm and by the enhancement of light emission from oxygen-deficient centers in oxide in the range of 350–700 nm. Subsequent annealing at 1000 or 1100°C results in the healing of defects and, correspondingly, in the weakening of the related photoluminescence peaks and also recovers in part the photoluminescence of silicon nanocrystals if the carbon dose is less than the silicon dose and results in the intensive white luminescence if the carbon and silicon doses are equal. This luminescence is characterized by three bands at ∼400, ∼500, and ∼625 nm, which are related to the SiC, C, and Si phase inclusions, respectively. The presence of these phases has been confirmed by electron spectroscopy, the carbon precipitates have the sp3 bond hybridization. The nanosized amorphous inclusions in the Si+ + C+ implanted and annealed SiO2 layer have been revealed by high-resolution transmission electron microscopy.

The effect of design parameters, electrical properties, and technological modes of formation on the efficiency of the photoelectrical conversion of solar cells with extremely thin absorbing layers based on the SnO2:F/TiO2/In2S3/InxPb1 − xS/CuSCN is investigated. It is shown that both a decrease in resistance due to an increase in roughness and a decrease in the average grain size of the TiO2 films is attained with deposition using the sol-gel method under conditions of increased humidity. The use of Ni as the contact metal to a planarizing CuSCN layer provides the reduced value of the transient resistance. The optimization of the sequential resistance of the TiO2 film and contact resistance to the CuSCN layer provided an increase in the efficiency of photoelectric converters by a factor of more than four. The structures of solar cells formed in optimal technological modes showed the following characteristics: Jsc = 9 mA/cm2, Uoc = 720 mV, and they had an efficiency of 2.9%.

The photoluminescence of various Si ion implanted oxide layers annealed at high-temperature has been studied in the range of 350–1500 nm. The set of investigated oxide materials includes thermal SiO 2 , deposited SiO 2 , Si 0.9 Ge 0.1 O 2 , GeO 2 films on silicon substrate, and sapphire wafers. The results are discussed in terms of generation and modification of the defect centers and nanoclusters formation taking into account several factors related to composition and structure of the original oxide matrices.

Bipolar resistive switching in metal-insulator-metal structures based on a double-layer insulator composed of a layer of yttria-stabilized zirconia (YSZ) containing 12 mol % Y2O3 and a layer of GeOx is studied. It is shown that the incorporation of an additional GeOx layer into the structure leads to a significant decrease in the variation of resistive switching parameters at both negative and positive voltages. Au/Zr/GeOx/YSZ/TiN structures exhibit a high stability of the resistance ratio in high-resistance and low-resistance states during cyclic switching. The studied structures can be used for designing next-generation nonvolatile memory elements.

The photoluminescence (PL) of Si + -implanted SiO 2 thermal films and ( 1 1 ¯ 0 2 ) sapphire substrates was studied for wide ranges of ion doses and annealing temperatures ( T ann ). The regularities of the PL at 780 nm from Si nanocrystals (NC) embedded in SiO 2 matrix for T ann = 1000 – 1200 ° C are described based on a model that takes into account coalescence of nearest NCs and dependence of radiative recombination rate on the NC size. Two PL bands found in Si + implanted Al 2 O 3 before and/or after annealing ( T ann = 500 – 1100 ° C ) are compared with those from Ar + -implanted samples and referred to the emission from Si NCs and defects.

The formation of thin titanium oxide films by pulling substrates from an alcohol solution of titanium tetraisopropoxide has been investigated. It is shown that the deposited titanium oxide layer consists of a continuous film and titanium oxide globules on its surface. It is found that the density and height of the globules depend on the pulling rate from the solution and the relative humidity in the working chamber, while the thickness of the continuous titanium oxide film is relatively constant.

Technological features of nanoprofiling of silicon protected by a solid mask based on porous aluminum oxide are considered. It is shown that, for a nanoprofiled silicon surface to be formed, it is advisable that combined dry etching be used including preliminary bombardment of structures with accelerated neutral atoms of an inert gas followed by reactive ion etching.

It has been shown that the central-cell potential of a phosphorus ion embedded in a silicon nanocrystal effectively mixes the electronic states of X- and � -bands. Quantum confinement strengthens the � ‐X mixing which, in turn, straightens the nanocrystal’s band structure, and substantially intensifies interband radiative recombination. (Some figures in this article are in colour only in the electronic version)