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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Документ 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.Документ 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.Документ 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.Документ 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.