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Information × Registration Number 0218U006178, 0115U003057 , R & D reports Title Mathematical modeling and experimental research of the formation of low-dimensional solid-state functional materials using intense laser and ion flows. popup.stage_title Head Kiyak S.G.. Popovych D.I., Registration Date 27-03-2018 Organization Pidstryhach Institute of Applied Problems of Mechanics and Mathematics NAS of Ukraine popup.description2 Research object - low-dimensional functional materials and structures on their base obtained by means of intense laser and ion fluxes. Research goal - elaboration of physico-mathematical models of ion-beam and laser modifications of materials that includes: establishing and comparative analysis of conductivity type conversion mechanisms in thin films CdxHg1-xTe by the ion implantation and material ion etching during the process of photosensitive structures formation for the optoelectronic devices of IR spectral region; development of laser reactive technology for the production of modified nanopowder oxide materials and structures on their base, study of their physico-chemical properties, gas sensing characteristics and development on their base the gas sensors with high sensitivity, speed and selectivity. Methods: mathematical modeling of structure and electronic properties formation process of the low-dimensional solid-state structures; experimental methods of electron-microscopy, X-ray-diffraction, Auger-spectroscopy and optical analysis methods. The regularities of formation, growth morphology, structure and electronic properties of nanoclusters ZnO, including during the adsorption of different gases, on them was established using methods the density functional theory and the molecular dynamics. The processes of laser ablation of metallic targets are studied and the mechanism of formation of metal oxide nanopowders and structures on their base in the chemically active environment are established. Correlations between the chemical composition, microstructure and electronic properties of laser-modified and doped ZnO nanopowder materials and structures on their base and their gas sensitivity are established for gas sensor technology. The processes and features of surface doping of nanopowders by impurities Pt, Au, Ag, Sn, Ti, Ni by means of laser and their influence on the sensitivity, selectivity of the signal response during adsorption of gases are studied. Electro-physical and optical investigations of defect structure of CdHgTe films grown by molecular-beam epitaxy were carried out. It was shown that the films contained neutral defects, which were formed at the stage of the growth and were specific to molecular-beam epitaxy - grown material. It is suggested that the defects in question are tellurium nanocomplexes. Under ion milling, these defects are activated by interstitial mercury and form donor centers with concentration of ~1017 cm-3. It is shown also, that under arsenic doping of CdHgTe with high-temperature cracking, the dimers As2 in the arsenic flux block formation of neutral Te nanocomplexes with formation of As2Te3 donor complexes. The results of electro-physical investigations are compared to these of micro-Raman spectroscopy. The influence of the parameters of colloidal synthesis on the photoluminescence properties of quantum dots based on CuInХ2 (X = S, Se) has been studied and stable protocols for synthesis of nanoparticles in the form of a "core-shell" with sizes of 3-20 nm and high quantum yield have been developed. The shift of the maximum of luminescence was achieved by cation exchange (Cu+, In3+) ? Zn2+, partial or complete replacement of sulfur anions with selenium anions, and control of the size of the nucleus to achieve a confinement regime. A two-step method for the formation of a ZnS shell has been developed, which allows the preservation the of photoluminescence during radical polymerization in styrene, lauryl methacrylate and can be extended to other materials/composites. A physico-mathematical model of light propagation through a spectral converter and a photovoltaic window based on the Monte Carlo method for cadmium-free quantum dots was developed. The short-circuit current amplification effect is simulated for some common and promising solar cell types. Product Description popup.authors Бовгира Р.В. Бончик О.Ю. Жировецький В.М. Кияк С.Г. Лесюк Р.І. Попович Д.І. Савицький Г.В. Савка С.С. Середницький А.С. popup.nrat_date 2020-04-02 Close