It was demonstrated that the concentration of nickel atoms near the surface of solar cells (SCs) is higher by 2–3 orders of magnitude in comparison with the bulk material, resulting in a ...significantly increased gettering rate in the former case. Experiments determined the optimal gettering conditions for nickel clusters (nickel diffusion temperature 800–850°C and additional thermal annealing temperature 750–800°C) and the structure of a silicon SC that enhances its efficiency by 25–30% in comparison with the reference structure. Physical mechanisms were identified for the effect of the diffusion of nickel impurity atoms and additional thermal annealing on the state of nickel atoms near the surface and the SC base and, consequently, on SC parameters. Physical models were developed for the structure of a cluster of nickel atoms in silicon and for the gettering process of fast-diffusing impurities by clusters of nickel atoms. The binding energy of fast-diffusing impurity atoms with a nickel cluster was estimated to be approximately 1.39 eV. Calculations showed that nickel doping can increase the minority carrier lifetime and the collection coefficient by factors of 2–4 and 1.4–2, respectively. Experiments demonstrated a twofold increase in minority carrier lifetime and a 25–30% improvement in the efficiency of SCs.
The effect of doping with nickel on the radiation stability of silicon solar cells has been studied within a γ-radiation dose range of 10
5
–10
8
rad. It has been shown that the diffusion doping of ...silicon with impurity nickel atoms increases the radiation stability of the parameters of silicon solar cells. It is implied that a reason of increase in the radiation stability of such solar cells is the existence of clusters, which are composed of impurity nickel atoms and serve as sinks for radiation defects.
ABSTRACT
GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger Addicts) is a network of 25 telescopes of different sizes, including both photometric and spectroscopic facilities. The ...network aims to coordinate follow-up observations of gravitational-wave (GW) candidate alerts, especially those with large localization uncertainties, to reduce the delay between the initial detection and the optical confirmation. In this paper, we detail GRANDMA’s observational performance during Advanced LIGO/Advanced Virgo Observing Run 3 (O3), focusing on the second part of O3; this includes summary statistics pertaining to coverage and possible astrophysical origin of the candidates. To do so, we quantify our observation efficiency in terms of delay between GW candidate trigger time, observations, and the total coverage. Using an optimized and robust coordination system, GRANDMA followed-up about 90 per cent of the GW candidate alerts, that is 49 out of 56 candidates. This led to coverage of over 9000 deg2 during O3. The delay between the GW candidate trigger and the first observation was below 1.5 h for 50 per cent of the alerts. We did not detect any electromagnetic counterparts to the GW candidates during O3, likely due to the very large localization areas (on average thousands of degrees squares) and relatively large distance of the candidates (above 200 Mpc for 60 per cent of binary neutron star, BNS candidates). We derive constraints on potential kilonova properties for two potential BNS coalescences (GW190425 and S200213t), assuming that the events’ locations were imaged.
In this paper, an initial boundary value problem for nonlinear Klein‐Gordon equation is considered. Giving an additional condition, a time‐dependent coefficient multiplying nonlinear term is ...determined, and existence and uniqueness theorem for small times is proved. The finite difference method is proposed for solving the inverse problem.
A model of a thermoelectric device for extracting foreign bodies from the human body by freezing is presented. The model was implemented by solving the heat conduction problem, taking account of the ...phase transition of the substance and the thermophysical properties of the biological object, the foreign body, and the thermoelectric cooling module. Numerical modeling yielded relationships between the time to complete freezing of the moist sponge, which determines the time required to attach the foreign body to the probe, and the cooling capacity of the thermoelectric cooling module. The relationships were determined for different thicknesses of the sponge. The device was shown to be compatible with a standard thermoelectric cooling module with a refrigeration power of 5000-10,000 W/m
2
corresponding to treatment durations of 112 to 28 s, respectively.
We consider a one-dimensional mixed problem for one class of third-order partial differential equations with nonlinear right-hand side. The concept of generalized solution of this problem is ...introduced. By the Fourier method, the problem of existence and uniqueness of generalized solutions for this problem is reduced to the problem of solvability of a countable system of nonlinear integrodifferential equations. By using Bellman’s inequality, we prove the uniqueness of generalized solution. Under certain conditions imposed on the initial functions and the right-hand side of the equation, the existence theorem is proved for the generalized solution by the method of successive approximations.
It is shown that in the near-surface region of the solar cells (SCs) the concentration of nickel atoms is higher than in the bulk by 2–3 orders of magnitude, therefore, the gettering rate in the ...near-surface region is higher. Optimal modes of gettering by nickel clusters (i.e., nickel diffusion – Т = 800–850 °С, additional thermal annealing – Т = 750–800 °С) and the structure of a silicon SC were experimentally determined, which makes it possible to increase the efficiency of silicon SCs by 25–30% relative to the control. The physical mechanisms of the influence of the processes of diffusion of impurity nickel atoms and additional thermal annealing on the state of nickel atoms in the near-surface region and the SCs base and, accordingly, on the parameters of the SC are revealed. Physical models of the structure of a cluster of nickel atoms in silicon and the process of fast diffusing impurities gettering by clusters of nickel atoms are created. The binding energy of fast dissusing impurities atoms with a nickel cluster is estimated to be ~ 1.39 eV. The calculation shows that doping with nickel can increase the lifetime of minority charge carriers by 2–4 times, and the collection coefficient by 1.4–2 times. The experiment showed an increase in the minority charge carriers lifetime up to 2 times and an increase in efficiency by 25–30%.
The study of the ferromagnetic properties of silicon diffusion-doped with manganese impurity atoms makes it possible to determine the magnetic properties of this material. Depending on the technology ...of obtaining such samples, manganese may be located predominantly in the nodes or interstices of the silicon crystal lattice. It has been established that observations of the ferromagnetic properties of silicon are mainly related to the concentration of holes and the exchange interaction of holes in silicon. The study showed that the d-shell of manganese atoms can be filled with electrons, which leads to the appearance of the magnetic property of silicon doped with manganese atoms. The obtained research results showed a possibility to obtain a magnetic material with ferro-magnetic properties based on silicon doped with manganese impurity atoms, which can be widely used in the creation of spintronic devices in magnetoelectronics.
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