Optical Losses of Thin Solar Cells on the Basis of n-ZnS / p-CdTe and n-CdS / p-CdTe Heterojunctions

The optical reflection and absorption losses in the accessory layers of solar cells based on n-ZnS / p- CdTe and n-CdS / p-CdTe heterojunctions are defined in this work. Aluminum doped zinc oxide is used as the front conductive layer material. It is shown that the replacement of traditional window material (CdS) for a wide-one (ZnS) leads to an increase in accessory solar cells layers transmittance. When the thickness of the window layers is 50 nm, the transmittance using ZnS windows with the wavelength of 380-500 nm is higher in 7-40 % than the corresponding value for CdS. At 300 nm for the same spectral field the difference increases to 8-89 %. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3559

High-temperature injection spectroscopy of deep traps in CdTe polycrystalline films

The paper provides the direct experimental method to determine the localized state energy distribution function for semiconducting solid materials based on space-charge-limited current-voltage characteristics. The current-voltage characteristics would be obtained under the random temperatures. The Tikhonov regularization method was used to solve the Fredholm 1st rank equation. The method developed in this research was used for the study of deep traps in CdTe polycrystalline films obtained in quasi-closed-tube on the conducting substrate. In the bend gap of the material, some traps were traced, which can be described by the close to Gaussian distribution parameters as well as by the parameter of energy disorder = 0.015-0.04 eV. The research shows that the trap concentration and depend on the physical and technological conditions of the obtained films, while the energy of the traps depends on the impurity-defective material structure

Nanostructured ZnO, Cu2ZnSnS4, Cd1−xZnxTe Thin Films Obtained by Spray Pyrolysis Method

The paper presents the investigation on the influence of substrate temperature Ts and the sprayed initial solution volume Vs on structural, substructural, optical properties, and elemental composition of ZnO and Cu2ZnSnS4 (CZTS) films as well as state-of-the-art of studying the Cd1−xZnxTe (CZT) films obtained by spray pyrolysis technique. The single-phase nanocrystalline ZnO films with average crystallite size of DC = 25–270 nm and thickness of d = 0.8–1.2 μm can be deposited at substrate temperatures of Ts > 473 K. The continuous CZTS films with optimal thickness (d = 1.3 μm) for application as absorber layers in solar cells were deposited at the sprayed initial precursor volume of Vs = 5 ml. The increase of the substrate temperature up to 673 K caused the significant improvements in the stoichiometry of ZnO films. The optimal stoichiometry ratio of CZTS films for application in solar cells was obtained at Vs = 3–4 ml. Optical study of ZnO films showed that these films have a high-transmission coefficient values of T = 60–80%. To the best of our knowledge, there is the lack of works devoted to the study of CZT films obtained by spray pyrolysis technique

Structural and optical characteristics of ZnSe and CdSe films condensed on non-oriented substrates

In this work, the complex investigation of structural and optical properties of zinc and cadmium selenide semiconductor films deposited by close-spaced vacuum sublimation method using thermal evaporation on non-oriented substrates was carried out. The structural and phase analyses of the layers condensed at different substrate temperatures were performed. The transmission and reflection spectra of the investigated films have been measured and their main optical characteristics have been calculated

On single-time methods in relativistic gravity dynamics

A short outline of revived methods of an action-at-a-distance description of interacting particles is given. A new approach to the problem of motion in relativistic gravity is discussed. The approach makes an essential use of the predictive relativistic mechanics method with some phenomenological assumptions as to the character of relativistic "forces". The technique of the construction of the approximate solutions for the Currie-Hill equations is proposed. Some recurrent conditions for these solutions are proved to be necessary and sufficient. The generalized Poincare´-invariant equations of motion are derived in post-Newtonian approximations of the phenomenological formulation of the relativistic action-at-a-distance gravity for the closed system of N structureless particles. Connections of these equations with those of the Lagrangian description are discussed.Подано стислий огляд розвитку Пуанкаре-інваріянтних методів опису механічної системи, що ґрунтуються на сучасній концепції прямої взаємодії. Обговорюється певний підхід до проблеми руху в релятивістичній теорії ґравітації. Підхід суттєво використовує методи предиктивної (з єдиним параметром еволюції) релятивістичної механіки із залученням певних феноменологічних припущень щодо характеру релятивістичних “сил”. Доведено необхідні та достатні умови для побудови в межах обговорюваного підходу наближених (у довільному порядку) розв’язків рівнянь Каррі-Хілла. Для замкнутої системи N ґравітуючих безструктурних точкових часток у пост-ньютонівському наближенні запропоновано узагальнені Пуанкаре-інваріянтні рівняння, які можуть застосовуватися при створенні нового, більш загального, формалізму верифікації релятивістичних теорій тяжіння. Обговорюються взаємозв’язки запропонованих рівнянь та рівнянь, що виникають у лаґранжевому формулюванні релятивістичної динаміки

Calculation of Fermi level location and point defect ensemble in CdTe single crystal and thin films

With the use of expressions obtained from the “first principles”, the ensemble of point defects was calculated, and the location of a Fermi level in undoped cadmium telluride single crystals and thin films depending on physico-technological conditions of their fabrication and annealing is determined. The model in use accounts the most complete spectrum of defects in chalcogenide, including defects in the cadmium and tellurium sublattices, and the existence of an antistructural defect on the cadmium sublattice. Calculations of the concentration of neutral and charged defects are realized for two extreme cases – full equilibrium and quenching. The comparison of the obtained results with the data of modeling provided with the use of a quasichemical formalism for a number of models most used presently is carried out. It is shown that all models describe well the results of Hall measurements of the concentration of free carriers in single crystals in the range of high cadmium pressure, but give essentially different results in the range of high tellurium pressure. Dominant defects in single crystals at high cadmium pressure and annealing temperatures are twice charged tellurium vacancies or interstitial cadmium atoms, which is in agreement with experimental results, as just such defects can provide the dependence of the concentration of free carriers on cadmium pressure as n ~ P¹/³Cd . A type of defects which are dominant in a tellurium-enriched material is determined by the chosen model. This allows us to make conclusions about the validity of the considered models and to specify the thermodynamic parameters of the defect creation processes in a material. The offered model can be used for modeling the ensemble of point defects in any А₂В₆ compounds. Thus, the problem of the choice of models adequate to experimental data is reduced to the determination of the creation energy for uncharged defects and the depth of energy levels of charged defects

Influence of aerosil on the nuclear magnetic relaxation and translational mobility of dimethyl sulfoxide

The transverse (T2) and longitudinal (T1) proton magnetic relaxation times and the self-diffusion coefficients D of the dimethyl sulfoxide (DMSO) molecules in aerosil mixtures with different specific surface area were measured at different temperatures and liquid contents. The large difference between the times T1 and T2 in the systems examined is explained by the hypothesis that the molecules adsorbed on the solid surface (especially in micropores) lose some translational degrees of freedom. At high temperatures, the translational displacement of DMSO molecules is determined by the relative time of their residence in the vapor phase. In contrast, it is the surface diffusion that determines this displacement at low temperatures, when the lifetimes of the adsorbed molecules are longer than the times of the measurement of the self-diffusion coefficient. © 1998 MAK Hayka/Interperiodica Publishing

Genotypically determined actin-adjustable water permeability of two transport channels of plasmodesmata in roots of the winter wheat seedlings

In roots of 5 - 6-day old seedlings of three cultivars of the winter wheat, varying in drought-resistance: Bezostaya 1 (low resistant), Mironovskaya 808 (resistant), and Albidum 114 (highly resistant) water permeability of two transport chanels of plasmodesmata was studied at the action of cytochalasin B, which is known to inhibit polymerization of cytoskeleton actin filaments, by a pulse method of NMR, on the background of increasing water loss in the seedlings. It has been found that the registered coefficient of water selfdiffusion, two of which (D2 and D3) depend on the water permeability of different transport channels of plasmodesta, differ in opposite directions. This may suggest that in roots drought-resistant plants, after a moderate water loss, a diffusive water flow through the cytoplasmic symplast increases (demonstrated by an increases of D2), while that through vacuolar symplast decreases (seen by an increase of D3). After a high water loss in seedlings, we noticed an even greater increase in water permeability of the cytoplasmic symplast, and a decrease in water permeability of the vacuolar symplast, however, in the roots of low resistant cultivars these changes were poorly expressed, if at all. Under stress-less conditions cytochalasin B would result in an increased water transport through cytoplasmic channel of plasmodesmata due apparently to a destruction of their actin-myosin sphincters. Both weak and average degrees of water loss would strengthen the cytochalasin B exerted influence on plasmodesmal water conductance, that may testify to a synergetic action of these two factors. After a significant water loss this action was kept only partially, because the inhibitor, on blocking the cytoplasmic channel, did increase at the same time the effect of water stress, limiting water flows through the vacuolar symplast and, simultaneously, raising the water inflow to the apoplast

NMR detection of phase transition in a ZSM-5 silicalite caused by the adsorbed hexane and decane molecules

Times of longitudinal T1b and transverse T2b magnetic relaxation of hexane and decane molecules in micropores of ZSM-5 silicalite were measured as functions of the content of these liquid n-alkanes in zeolite and of temperature. The stepwise changes in the T1b and T2b times were revealed in the region of 8% content of hydrocarbons. The observed changes in the concentration and temperature dependences of T1b and T2b times are explained by the rearrangement of silicalite crystal lattice under the action of adsorbed molecules

Empirical Therapy of Complicated Pyelonephritis

The aim of the research was to analyze the effectiveness of empirical therapy in patients with established complicated upper urinary tract infection (complicated pyelonephritis).Materials and methods. 51 patients who were treated in 2018 in the urological department of the Irkutsk City Clinical Hospital N 1 were subjected to a retrospective study. The average age of patients was 55.9 ± 16.9 years.Results. Successful empirical therapy was considered in the absence of correction of the treatment regimen and the normalization of clinical blood and urine tests. Of the patients included in the study, successful empirical therapy was found in 24 (47%) patients, and required correction in 27 (52.9 %) patients. Cephalosporins as monotherapy were ineffective in 24 (57.1 %) patients, carbopenems – in one (25 %), fluoroquinolones – in all (100 %). Aminoglycosides showed the best result as a combination therapy with cephalosporins – 100 % (n = 3) of success. Based on multivariate logistic regression analysis, it was established that the detection of microhematuria and uremia in clinical analyzes upon admission to the hospital increases the likelihood of empirical monotherapy with third-generation cephalosporins by 20 % and 27 %, respectively.Conclusion. It is advisable to refrain from the use of monotherapy with fluoroquinolones and third-generation cephalosporins until more information is available about the resistance of uropathogens in the population of the Irkutsk region. Patients with impaired renal function require particularly close attention of the clinician when choosing a scheme for the empirical treatment of complicated pyelonephritis