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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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.
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.
Study Solid Solutions in CdS/CdTe Thin Films Heterosystems Obtaine by DC Magnetron Sputtering
(Institute of Electrical and Electronics Engineers, 2018) Dobrozhan, A. I.; Kopach, G. I.; Mygushchenko, R. P.; Khrypunov, G. S.; Harchenko, M. M.; Polezhaeva, O. V.
The influence of physical and technological condensation mode by direct current magnetron sputtering on the crystal structure and optical properties of grown CdS and CdTe films, CdS/CdTe thin films heterosystems was investigated. Traditional chloride treatment of thin-film CdS/CdТе heterosystem leads to recrystallization of CdTe basic layer and its wurtzite-sphalerite phase transition. After Cl treatment a bandgap in CdTe increases up to 1.5 eV. For CdS/CdТе heterosystem a decrease of a bandgap to 1.45 eV is observed which is determined by formation of solid solutions of CdSхТе₁₋ₓ at the interphase boundary of CdS/CdТе. The value of the stoichiometric parameter х=0,1±0,01 was calculated using the optical researches data.
Structure and Optical Properties of CdS Nanoscale Thin Films Obtained by Direct Current Magnetron Sputtering
(Institute of Electrical and Electronics Engineers, 2017) Kopach, G. I.; Mygushchenko, R. P.; Khrypunov, G. S.; Dobrozhan, A. I.; Harchenko, M. M.
The influence of physical and technological condensation mode by direct current magnetron sputtering with preheating of the target on the crystal structure and optical properties of grown CdS nanoscale thin films was investigated. CdS layers on glass substrates with hexagonal structure 80-100 nm thick under conditions plasma discharge current density is 1.1 mA/cm² and the deposition rate is 18-20 nm/min were obtained. The band gap CdS in nanoscale thin films is Eg=2,4-2,43 eV. After annealing in vacuum optical transparency of CdS films is 90%, which allows to use such nanoscale thin films as a transparent window layer in solar cells based on heterostructure of CdS/CdTe.