Influence of "productive" Impurities (Cd, Na, O) on the Properties of the Cu2ZnSnS4Absorber of Model Solar Cells

The research has been supported by grant of the Ministry of Education and Science of the Republic of Kazakhstan AP09562784. The authors (D. Sergeyev) acknowledges the provision of SCAPS-1D software by Prof. Marc Burgelman. The research of A.I. Popov has been supported by the Institute of Solid State Physics (ISSP), University of Latvia (UL). ISSP UL as the Centre of Excellence is supported through the Framework Program for Euro-pean Universities Union Horizon 2020, H2020-WIDESPREAD-01–2016–2017-TeamingPhase2 under Grant Agreement No. 739508, CAMART2 project.Abstract The study focuses on the optical properties of the CZTS multicomponent semiconductor absorber with 3 % "production"impurities of Cd, Na, O within the framework of the density functional theory using the generalized gradient approximation and the SCAPS program, as well as investigates their influence on the performance and efficiency of CZTS-solar cells. The results showed that the introduction of Cd, Na, O impurities would lead to a decrease in the intensity of the absorption bands at 2.06 eV and 2.55 eV. The density of states CZTS: (Cd, Na, O) was determined from first principles, and it was revealed that impurities of Cd and O atoms would lead to a decrease in the band gap (to 0.9 eV and 0.79 eV), and an increase in Na impurity absorption (1.2 eV). It was also found that a decrease in the band gap led to a decrease in the open circuit voltage, and it was also shown that "industrial"impurities led to a decrease in the efficiency of energy conversion of solar cells to 2.34 %. © 2021 D. Sergeyev et al., published by Sciendo. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.Ministry of Education and Science of the Republic of Kazakhstan AP09562784; ISSP UL as the Centre of Excellence is supported through the Framework Program for Euro-pean Universities Union Horizon 2020, H2020-WIDESPREAD-01–2016–2017-TeamingPhase2 under Grant Agreement No. 739508, CAMART2 project

Computer Simulation of the Electric Transport Properties of the FeSe Monolayer

The research has been supported by the grant of the Ministry of Education and Science of the Republic of Kazakhstan AP08052562. In addition, the research of AIP has been supported by the Latvian- Ukrainian Grant LV-UA/2018/2.The paper deals with the model research of electric transport characteristics of stressed and non-stressed FeSe monolayers. Transmission spectra, current-voltage characteristic (CVC) and differential conductivity spectra of two-dimensional FeSe nanostructure have been calculated within the framework of the density functional theory and non-equilibrium Green's functions (DFT + NEGF). It has been shown that the electrophysical properties depend on the geometry of the sample, the substrate, and the lattice constant. On CVC of non-stressed sample in the range from -1.2 V to -1 and from 1.2 V to 1.4 V, a region of negative differential resistance (NDR) has been observed. NDR is at both signs of the applied voltage due to the symmetry of the nanostructure. d2I/dV2 is used to determine the nature of the electron-phonon interaction and the features of quasiparticle tunnelling in stressed and non-stressed samples. The results obtained can be useful for calculating new elements of 2D nanoelectronics. © 2020 D. Sergeyev et al., published by Sciendo 2020. --//-- Published under the CC BY 4.0 license.Ministry of Education and Science of the Republic of Kazakhstan AP08052562, LV-UA/2018/2; The Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

The Deformation Stimulated Luminescence in KCl, KBr and KI Crystals

Currently, strengthening of the intensity of luminescence in alkali halide crystals (AHC) at lattice symmetry lowering is discussed as a promising direction for the development of scintillation detectors. In this regard, for the study of anion excitons and radiation defects in the AHC anion sublattice at deformation, the crystals with the same sizes of cations and different sizes of anions were chosen. In the X-ray spectra of KCl at 10 K, the luminescence at 3.88 eV; 3.05 eV and 2.3 eV is clearly visible. The luminescence at 3.05 eV corresponds to the tunneling recharge [F*, H]. Luminescence at 3.88 eV is quenched in the region of thermal destruction of F'-centers and characterizes tunneling recharge of F', VK-centers. In KCl at 90 K, the luminescence of self-trapped excitons (STE) is completely absent. In KBr at deformation not only STE luminescence, but also deformation stimulated luminescence at 3.58 eV were recorded, the last one corresponds to tunneling recharge of F', VK-centers. In KI crystal at 10 K and 90 K at deformation, only STE luminescence is enhanced. There are no deformation luminescence bands in KI compares with KBr and KCl crystals

Syncretism of Meanings in the Political Color Metaphor Krasnye Linii - Red Lines

В статье на материале заголовков новостных статей рассматривается политическая метафора "красные линии - red lines".The article considers significant problems of linguistic expansion in the epoch of intercultural communication. Verbalized identically in different languages, new realities, notions and concepts of actual political discourse are used in intercultural communication through the expansion of semantic fields and transformation of the existing content forms

Моделювання руйнування p-n-переходу електромагнітними імпульсами

У рамках теорії існування густини та методів молекулярної динаміки у статті розглядається процес руйнування кремнієвого p-n-переходу під дією електромагнітного імпульсу (термічний ефект). Зі збільшенням амплітуди електромагнітного імпульсу виникає нелінійність рухливості квазічастинок і відбуваються процеси ударної іонізації, що приводять до утворення різноманітних дефектів у кристалічній решітці напівпровідника. Показано еволюцію виникнення точкових дефектів у напівпровіднику шляхом термічної деформації, а також подальше збільшення їх концентрації. Показано, що первинне проходження електромагнітного імпульсу породжує дефекти в бездефектному кристалі. Подальший термічний вплив імпульсу приводить до збільшення відхилення атомів та накопичення дефектів і руйнування структури. З підвищенням температури p-n-перехід втрачає свої випрямляючі властивості і спостерігається миттєве збільшення величини зворотного струму за рахунок виникнення струму іонізації, який збігається за напрямком зі струмом насичення. Виявлено, що термічна деформація суттєво спотворює профіль p-n-переходу. Встановлено, що руйнування напівпровідникової структури відбувається в бездефектній частині кристала. У напівпровідниках, легованих Li або Sr, час руйнування p-n-переходу збільшується за рахунок заселення рухливими іонами Li або Sr утвореними вакансіями кремнію під час теплової дії імпульсу. Отримані результати можуть бути корисними при розробці напівпровідникових структур, стійких до зовнішнього впливу електромагнітного імпульсу.Within the framework of the density functional theory and methods of molecular dynamics, the process of destruction of a silicon p-n junction at the influence of an electromagnetic pulse (thermal effect) is considered. With an increase in the amplitude of the electromagnetic pulse, a nonlinearity of the mobility of quasiparticles arises and impact ionization processes occur, leading to the formation of various defects in the crystal lattice of the semiconductor. The evolution of the occurrence of point defects in a semiconductor by thermal deformation, as well as a further increase in their concentration, is shown. It is demonstrated that the primary passage of an electromagnetic pulse generates defects in a defect-free crystal. Further thermal impact of the pulse leads to an increase in the deviation of atoms, leading to the accumulation of defects and the destruction of the structure. With an increase in temperature, the p-n junction loses its rectifying properties and an instantaneous increase in the magnitude of the reverse current is observed due to the occurrence of an ionization current, which coincides in direction with the saturation current. It is revealed that thermal deformation significantly distorts the p-n junction profile. It was found that the destruction of the semiconductor structure occurs in the defect-free part of the crystal, and the defects stimulate destruction. In semiconductors doped with Li or Sr, the destruction time of the p-n junction increases due to the occupation of mobile Li or Sr ions by the formed silicon vacancies during the thermal action of the pulse. The results obtained can be useful in the development of semiconductor structures resistant to external influences of an electromagnetic pulse

Computer Simulation of the Electric Transport Properties of the FeSe Monolayer

The paper deals with the model research of electric transport characteristics of stressed and non-stressed FeSe monolayers. Transmission spectra, current-voltage characteristic (CVC) and differential conductivity spectra of two-dimensional FeSe nanostructure have been calculated within the framework of the density functional theory and non-equilibrium Green’s functions (DFT + NEGF). It has been shown that the electrophysical properties depend on the geometry of the sample, the substrate, and the lattice constant. On CVC of non-stressed sample in the range from −1.2 V to −1 and from 1.2 V to 1.4 V, a region of negative differential resistance (NDR) has been observed. NDR is at both signs of the applied voltage due to the symmetry of the nanostructure. d2I/dV2 is used to determine the nature of the electron-phonon interaction and the features of quasiparticle tunnelling in stressed and non-stressed samples. The results obtained can be useful for calculating new elements of 2D nanoelectronics