Кафедра "Природничі науки"

Постійне посилання колекціїhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/1703

Увага! Поповнення колекції кафедри "Природничі науки" від травня 2023 року тимчасово призупинено.

Офіційний сайт кафедри http://web.kpi.kharkov.ua/ken

Кафедра "Природничі науки" заснована в 1973 році.

Кафедра забезпечувала викладання дисциплін природничого циклу іноземним громадянам, які готуються продовжувати навчання у вищих навчальних закладах України.

Студенти отримують необхідний рівень знань з природничих дисциплін і мають можливість вступати в будь-які вузи України для подальшого навчання.

Кафедра входить до складу Навчально-наукового інституту міжнародної освіти Національного технічного університету "Харківський політехнічний інститут".

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Advanced capacitive converters based on Al/ITO/Polyimide/Al₂O₃ heterostructures
(Vasyl Stefanyk Precarpathian National University, 2015) Zaitseva, L. V.; Khrypunov, G. S.; Zaitsev, R. V.; Momotenko, O. V.
Hybrid solar generating module development for high-efficiency solar energy station
(Сумський державний університет, 2018) Zaitsev, R. V.; Kirichenko, M. V.; Khrypunov, G. S.; Prokopenko, D. S.; Zaitseva, L. V.
Experimentally established, the influence of the working temperature and solar radiation power on the efficiency of industrial production silicon solar cells. Based on the experimental results designed the concept of a hybrid solar generating module equipped with a mirror concentrator of solar radiation and solar cells cooling system for using in high-performance solar energy station. Concentrator of solar radiation provides in 1.5-time increase of electrical power generating by such module, and water-cooling system can reduce the equilibrium temperature of the module up to 10 degrees and twice reduce efficiency losses from solar cells overheating. The proposed concept will reduce the number of modules needed to build solar energy station.
Operating temperature effect on the thin film solar cell efficiency
(Сумський державний університет, 2019) Zaitsev, R. V.; Kirichenko, M. V.; Khrypunov, G. S.; Radoguz, S. A.; Khrypunov, M. G.; Prokopenko, D. S.; Zaitseva, L. V.
The made research results of the dependence of the film photovoltaic converter efficiency on their operating temperature and their comparison are considered in the paper. The physical mechanisms of temperature influence analysis on output, diode and electronic parameters of photovoltaic converters were conducted. The output parameters determination of the flexible photovoltaic converters was carried out by measurement of light current-voltage characteristics by using illuminator based on powerful semiconductor LEDs with different colors for simulated radiation which is close to the standard ground and ultraviolet solar spectrum. For ensuring effective non-destructive switching of the test specimens of the flexible PVC based on cadmium telluride to the measurement circle, the special contact device was developed and used. The main feature of contact device is four separate vertically moving metal probes in form of semi spheres with polished surfaces, which makes it impossible to puncture the PVC electrodes. These probes have possibility of individual positioning of each probe that is carried out with the help of a hard rotary console of variable length attached to the body and can be pressed with a given effort without impact on the frontal and any rear electrodes of the PVC experiments. The efficiency temperature coefficients of the photovoltaic converter, which make up for devices with a CdTe of 0.14 %/C, CuInSe2 – 0.36 %/C, amorphous silicon - 0.21 %/C were obtained. The analytical processing and analysis of the light diode characteristic effect on the PVC efficiency based on the CdTe showed that the temperature stability of their efficiency is ensured by the diode current density, the incision of which increases by 50 % from 1.9·10 – 9 A to 2.7·10 – 9 A with the temperature rise from 20 °С to 50 °С. At the same time, it has been established for PVC on the CuInSe and amorphous silicon base that the decrease of short circuit current density, open circuit voltage and fill factor of current-voltage characteristics plays the main role in efficiency reduction with rising temperature.
Calculation of operating parameters of high-voltage power take-off system for the photovoltaic facility
(ТОВ "Друкарня "Мадрид", 2016) Zaitsev, R. V.; Kyrychenko, M. V.; Kholod, A. V.; Zaitseva, L. V.; Prokopenko, D. S.; Khrypunov, G. S.
To ensure maximum production of electric power by photovoltaic vacilities, in addition to using highly efficient photovoltaic modules equipped with solar radiation concentrators must use a highly effective power take-off system. This paper is inscribed to solving the problem of a highly efficient and economic power take-off system development. Methodology. To solving the problem, we implemented three stages. On the first stage examines the dependence of electrical power from the intensity of the incident solar radiation. Based on this, the second stage is calculated the DC-DC converter resonant circuit and its working parameters, and developed circuit diagram of DC-DC converter. On the third stage, we carry out an analysis of power take-off system with step up DC-DC converter working. Results. In this paper, we carry out the analysis of working efficiency for photovoltaic facility power take-off system with step-up boost converter. The result of such analysis show that the efficiency of such system in a wide range of photovoltaic energy module illumination power is at 0.92, whereas the efficiency of classic power take-off systems does not exceed 0.70. Achieved results allow designing a circuit scheme of a controlled bridge resonant step-up converter with digital control. Proposed scheme will ensure reliable operation, fast and accurate location point of maximum power and conversion efficiency up to 0.96. Originality. Novelty of proposed power take-off system solution constitute in implementation of circuit with DC-DC converters, which as it shown by results of carrying out modeling is the most effective. Practical value. Practical implementation of proposed power take-off system design will allow reducing losses in connective wires and increasing the efficiency of such a system up to 92.5 % in wide range of photovoltaic energy modules illumination.
The influence of physical and technological magnetron sputtering modes on the structure and optical properties of CdS and CdTe films
(Інститут фізики напівпровідників ім. В. Є. Лашкарьова, 2017) Khrypunov, G. S.; Kopach, G. I.; Harchenko, M. M.; Dobrozhan, A. I.
To create technology for preparation of CdS and CdTe thin films by direct current magnetron sputtering, the influence of physical and technological condensation modes on the crystal structure and optical properties of these films were investigated. The laboratory method of DC magnetron sputtering with preheating of the target for the mentioned films on glass substrates was developed. We obtained the CdS layers with hexagonal structure 150…200 nm thick under conditions when the plasma discharge current density was 1.1 mA/cm² and the deposition rate – 30…40 nm/min. The bandgap in the obtained CdS films is Eg = 2.38…2.41 eV. After annealing in vacuum, the optical transparence of CdS films reaches 80…90%, which allows to use these films as a transparent window layer in solar cells based on heterojunctions of CdS/CdTe. When the plasma discharge current density is 2.2…5.4 mA/cm² and the deposition rate is 200 nm/min, we obtained CdTe layers with hexagonal structure up to 5 μm thick. The transmittance of CdTe films with hexagonal structure in the wavelength range of the visible spectrum is up to 5%, and in the infrared spectral range is about 60%. The bandgap in the obtained CdTe layers of different thickness is 1.52…1.54 eV. After chloride treatment as a result of the phase transition wurtzite-sphalerite, the investigated CdTe films contain only the stable cubic structure and can be used as a base layer of solar cells.
Adopting of DC Magnetron Sputtering Method For Preparing Semiconductor Films
(Institute of Electrical and Electronics Engineers, 2017) Kirichenko, M. V.; Zaitsev, R. V.; Dobrozhan, A. I.; Khrypunov, G. S.; Kharchenko, M. M.
It has been carried out the experimental studies of the process of cadmium telluride magnetron sputtering with direct current, and the impact of a magnetron sputtering mode on CdTe films crystalline structure. In order to create thin-film solar cells based on cadmium sulfide and telluride CdTe films for the base layers of thin film solar cells was obtained on flexible polyimide substrates by magnetron sputtering with direct current for the first time. It has found that increasing the magnetron discharge current up to 80 mA leads to increase in coherent scattering regions what is due to an increase in the thickness of the cadmium telluride films of the hexagonal modification having a columnar structure.
Structure and Properties of the Cadmium Sulfide Films Received by Magnetron Dispersion Method
(Сумський державний університет, 2017) Zaitsev, R. V.; Kirichenko, M. V.; Mygushchenko, R. P.; Veselova, N. V.; Khrypunov, G. S.; Dobrozhan, A. I.; Zaitseva, L. V.
For the purpose of creation of the economic, suitable for large-scale application technology of formation of a layer of wide-scale "window", for thin-film photo-electric converters on the basis of sulfide and telluride of cadmium the pilot studies of temperature effect of a deposition of the films of sulfide of cadmium received by method of magnetron dispersion on a direct current on their optical properties and crystalline structure were conducted. By method of a two-channel optical spectroscopy it is established that a deposition of films of sulfide of cadmium at a temperature of 160 °C allows to form layers with a width of forbidden region of 1,41 eV that approaches value, characteristic of monocrystals, and the density of the photon flux passing through a cadmium sulfide layer in a spectral interval of a photosensitivity of telluride of cadmium at the level of 37,0 W·nm·cm².
Structure and Optical Properties CdS and CdTe Films on Flexible Substrate Obtained by DC Magnetron Sputtering for Solar Cells
(Сумський державний університет, 2017) Kopach, G. I.; Mygushchenko, R. P.; Khrypunov, G. S.; Dobrozhan, A. I.; Harchenko, M. M.
The paper describes investigate of crystal structure and optical characteristics of the CdS transparent window layers and the CdTe base layers, obtained by direct current magnetron sputtering on glass or polyimide substrate, and output parameters the flexible thin film solar cells based on them. The band gap in obtained hexagonal CdS films is Eg = 2.38-2.41 eV and optical transparency of CdS films is 80-90%. Conducting chloride treatment of CdTe layers, obtained at Tп < 300 °C, promotes wurtzite-sphalerite phase transition. Cooling ITO/CdS layers to room temperature before CdTe deposition, removal of the air and subsequent heating in vacuum to the required temperature of the substrate leads to an increase of the energy conversion efficiency and open circuit voltage of the polyimide/ITO/CdS/CdTe/Cu/Ag flexible solar cell.
Structure and optical properties of CdS polycrystalline layers for solar cells based on CdS/CdTe
(Науково-технологічний комплекс "Інститут монокристалів", 2019) Khrypunov, G. S.; Kopach, G. I.; Dobrozhan, A. I.; Mygushchenko, R. P.; Kropachek, О. Y.; Lyubov, V. M.
Thin CdS films about 200-500 nm thick with stable hexagonal modification with 85-80 % transparency value respectively in the visible and infrared spectrum regions were investigated. The use of the FTO sublayer to obtain heterosystem glass/FTO/CdS by magnetron sputtering does not affect the phase composition of the cadmium sulfide layer and the width of the band gap (Eg = 2.42-2.44 eV). Cadmium sulfide thin films, obtained by direct current magnetron sputtering, can be used as a layer of a wide window layer in thin-film solar cells based on the CdS/CdTe heterosystem.
Structure and Optical Properties of CdTe and CdS Thin Films after Hard Ultraviolet Irradiation
(Прикарпатський національний університет ім. Василя Стефаника, 2019) Kopach, G. I.; Dobrozhan, A. I.; Khrypunov, G. S.; Mygushchenko, R. P.; Kropachek, О. Y.; Zaitsev, R. V.; Meriuts, A. V.