Influence of Ultrasonic Waves on Current-Voltage Characteristics and Polarization Effects of Si-N-P Radiation Receivers

The currents of n-p junctions and polarization effects caused by the capture processes of diffusion Si-receivers (detectors) of radiation exposed by ultrasound have been analyzed in this work. It was found that there are local concentrations of impurity atoms with an effective size l>6μm30μm in Si-n-p radiation receivers. They determine the behavior of the signal amplitude in different intervals of electric and temperature fields. It was found that at Е>1500V/cm and T>168K, the efficiency of collecting nonequilibrium charge carriers significantly increases and doublets of spectral α-lines and “humps” disappear at the temperature dependences of the signal amplitude. The main physical processes and mechanisms that determine the appearance of the phenomenon of "polarization" of Si-n-p-detectors were investigated. This phenomenon is caused by the existence of local gold atoms, which arise in the process of manufacturing technology of Si-n-p-receivers and act as effective trapping centers.

Compact Model for Bipolar and Multilevel Resistive Switching in Metal-Oxide Memristors

The article presents the results of the development and study of a combined circuitry (compact) model of thin metal oxide films based memristive elements, which makes it possible to simulate both bipolar switching processes and multilevel tuning of the memristor conductivity taking into account the statistical variability of parameters for both device-to-device and cycle-to-cycle switching. The equivalent circuit of the memristive element and the equation system of the proposed model are considered. The software implementation of the model in the MATLAB has been made. The results of modeling static current-voltage characteristics and transient processes during bipolar switching and multilevel turning of the conductivity of memristive elements are obtained. A good agreement between the simulation results and the measured current-voltage characteristics of memristors based on TiOx films (30 nm) and bilayer TiO2/Al2O3 structures (60 nm/5 nm) is demonstrated.

Влияние межмолекулярного взаимодействия на нелинейно-оптические свойства в системах COANP-углеродные наночастицы

The main results of non-linear optical, spectral and current-voltage characteristics research of pyridine organic conjugated molecule-carbon nanoparticles combined system have been presented. The perspective of these materials further study in global trends of modern search of materials for optical limiting has been demonstrated also in the present paper.

Термоэлектрические и мемристивные особенности структур Sb-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=-/Sb-=SUB=-2-=/SUB=-S-=SUB=-3-=/SUB=-/Sb-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=- и Ag/Sb-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=-/Ag

Single-layer Sb2Te3 films and three-layer Sb2Te3/Sb2S3/Sb2Te3 structures are obtained by thermal vacuum deposition. Their thermoelectric characteristics have been investigated in a wide temperature range (5350 K). It is shown that the conductivity of Sb2Te3/Sb2S3/Sb2Te3 has a semiconductor behavior, the resistivity is an order of magnitude higher than the resistivity of the Sb2Te3 film; the Seebeck coefficient of Sb2Te3/Sb2S3/Sb2Te3 is 1.5 and 3 times higher than the Seebeck coefficient of the film and single-crystal Sb2Te3, respectively. The currentvoltage characteristics of the Sb2Te3 film exhibit memristive properties with unipolar resistive switching, whereas Sb2Te3/Sb2S3/Sb2Te3 can be considered as a memristor with a parallel connected capacitance.

МДП транзистор на основе пленки PbSnTe : In с подзатворным диэлектриком Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=--=SUP=-*-=/SUP=-

Results on the creation and properties of transistor-type MIS structures (MIST) with an Al2O3 thin-film gate dielectric based on PbSnTe:In films obtained by molecular beam epitaxy are presented. The source-drain current-voltage characteristics (CVC) and gate characteristics of the MIST at Т = 4.2 К have been investigated. It is shown that in MIST based on PbSnTe:In films with n ~ 1017 cm-3 the modulation of the channel current reaches 7 – 8 % in the range of gate voltages – 10 V < Ugate < + 10 V. The features of the source-drain CVC and the gate characteristics for a pulsed and sawtooth variation of Ugate are considered.

Photoconductivity of Thin Films Obtained from a New Type of Polyindole

The optoelectronic properties of a new poly(2-ethyl-3-methylindole) (MPIn) are discussed in this paper. The absorption and photoluminescence spectra were studied. The electronic spectrum of MPIn showed a single absorption maximum at 269 nm that is characteristic of the entire series of polyindoles. The fluorescence spectra show that the emission peaks of the test sample are centered around 520 nm. The photoconductivity of thin film samples of MPIn polyindole was studied by measuring the current-voltage characteristics under ultraviolet radiation with a wavelength of 350 nm. Samples of phototransistors were obtained, where thin films of MPIn polyindole were used as a transport layer, and their characteristics were measured and analyzed. The value of the quantum efficiency and the values of the mobility of charge carriers in thin polyindole films were estimated.

Influence of different types of solvents on morphology, optical and conductive properties of PCBM films

The article deals with the influence of various types of solvents on the spectral characteristics and conductive properties of films [6,6]-methyl phenyl-C61-butyric acid, precipitated from solutions. It is clearly shown that the effect of the nature of the solvent affects the morphology of the film surface. Analysis of the spectra of the optical range showed the presence of a maximum of the absorption coefficient in the frequency range of 340-490 nm. The calculation of the optical bandgap clearly demonstrates the possibility of modernizing the atomic structure of films by using various types of solvents. A study of the current-voltage characteristics showed the presence of a photocurrent in carbon films deposited with dichloromethane, toluene, and chloroform.

THE USE OF LIQUID PROBES BASED ON AN EUTECTIC SOLUTION FOR STUDYING THE CONDUCTING PROPERTIES OF THIN FILMS

Работа посвящена разработке модульной четрырехзондовой установки с использованием жидкого контакта на основе индий-галлиевого эвтектического раствора (EGaIn), с помощью которого можно создать прижимные жидкие контакты, не вносящие механические деформации в измеряемые структуры. Предлагается использовать данную установку для измерения вольт-амперных характеристик тонкопленочных образцов. Предполагается модульная схема измерений. Каждый зонд управляется четырьмя моторами для позиционирования и выдавливания капли из шприца для формирования нужного размера пятна контакта. Используется оптический контроль для подготовки зондов и измерения диаметра сформированных контактных областей. Подобраны параметры изготовления жидких зондов, а именно скорости выдавливания и перемещения зонда вдоль вертикальной оси для формирования капли конической формы . Управление установкой осуществляется в среде LabView. The work is devoted to development of a modular four-probe setup using a liquid contact based on an indium-gallium eutectic solution (EGaIn), which can be used to create clamping liquid contacts that do not introduce mechanical deformation into the measured structures. It is proposed to use this setup for measuring the current-voltage characteristics of thin-film samples. A modular measurement scheme is assumed. Each probe is driven by four motors to position and expel a drop from the syringe to form the desired contact area size. Optical control is used to prepare the probes and measure the diameter of the formed contact areas. The parameters for the manufacture of liquid probes are selected, namely, the speed of extrusion and movement of the probe along the vertical axis to form a conical droplet. The installation is controlled in the LabView environment.

Optimal Relay Coordination with Hybrid Time–Current–Voltage Characteristics for an Active Distribution Network Using Alpha Harris Hawks Optimization

The miscoordination and malfunctioning of directional overcurrent relays (DOCR) may occur due to a significant change in the fault current level (FCL) and a change in the network topology, from a radial to ring topology, caused by renewable energy resource-based distributed generation (RES-DG). In this paper, a hybrid time–current–voltage (TCV)-based protection scheme is proposed to eliminate the DOCR miscoordination and to reduce the overall operation time of DOCRs. The DOCR coordination problem is solved with alpha Harris Hawks optimization (α-HHO). Detailed numerical studies are carried out, and to show the performance of the proposed scheme, the results are compared with the existing protection schemes in the recent literature.