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Fabrication of SiC optical metasurfaces
Štálnik, Jozef ; Idesová, Beáta (referee) ; Dvořák, Petr (advisor)
The aim of this bachelor's thesis was to optimize the manufacturing process of SiC meta-surfaces, which have emerged as a revolutionary replacement for classical optical elements due to their ability to control incident light through local phase modulation. Furthermore, it discusses the utilization of silicon carbide as a platform for these photonic devices and the experimental techniques employed in the meta-surface fabrication process. The experimental section presents the results of silicon carbide nanostructure fabrication, with dry plasma etching being the key optimization step. Finally, optical measurements of the phase profile of the resulting meta-surfaces are presented using off-axis digital holography. The main outcome of this work is the creation of a library of individual building blocks crucial for future applications.
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Gecko mimicking surfaces
Fecko, Peter ; Boušek, Jaroslav (referee) ; Pekárek, Jan (advisor)
Adhezní schopnosti gekona byly předmětem mnoha studií a inspirací pro vytvoření mnoha napodobenin. Tato práce navrhuje vlastní verzi umělých gekoních struktur ve tvaru mikroskopických pilířů, které by vykazovaly adhezní vlastnosti srovnatelné s tlapkou gekona. Vyrobeny byli struktury z polymeru Parylen C pomocí fotolitografie a technik na leptání křemíku. Dalším cílem bylo různými metodami pro modifikaci povrchu a charakterizaci vytvořených struktur, které určí adhezní síly těchto povrchů, před a po modifikacích.
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SELECTIVE EMITOR FOR THERMOPHOTOVOLTAIC SYSTEMS
Šimonová, Lucie ; Hrzina,, Pavel (referee) ; Šály,, Vladimír (referee) ; Vaněk, Jiří (advisor)
The work is focused on research and development of a suitable method for creating a selective emitter for the visible and near infrared region so that they are able to work optimally together with silicon photovoltaic cells in a thermophotovoltaic system. The aim of the work was to develop a new method of creating very fine structures outside the current standard, which will increase the emissivity of the base material to meet the needs of a selective emitter for the VID and NIR region. The methods available to us for the creation of structures were chosen, from which we eliminated all unsuitable ones and we introduced the optimal procedure and parameters for their creation for the selected method. In this work, we focused on both ceramic and metallic materials, whose heat resistance and selective properties are key to this work. Part of the development of the emitter structures was also the need for pretreatment of the substrate itself, where great emphasis was placed on the purity of materials and surface roughness. Since ceramic materials cannot achieve a surface roughness so low that the desired structures can be formed, these materials have been purposefully used primarily for the purpose of combining the base material with thin layers of other high temperature material. Their compatibility and suitability were verified in terms of adhesion and subsequent heat resistance. The main material for the formation of fine structures was purposefully chosen tungsten, for which we verified the influence of the formed structure on the emissivity as well as the thermal stability during long-term exposure to high temperatures. The work thus represents not only a new method of creating very fine structures, which are not normally formed in such subtlety, but also opens the way to new possibilities of combining more materials to achieve the required selectivity of the thermophotovoltaic emitter.
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Mechanical design of measurement system for reactive ion etching system
Maňka, Tadeáš ; Antoš, Martin (referee) ; Šerý, Mojmír (advisor)
The aim of this work is to design fully working measuring system for the reactive ion etching system (RIE). The Michelson interfometer, previously developed in Ústav přístrojové techniky, v.v.i., is used in this work. The theoretical part is aimed at description of interferometric methods for precise measuring of length. In next part the etching proces with RIE is described. In practical part the testing system was constructed from the parts of Thorlabs company . The functionality was controlled with this system and the results of measuring were compared with the profilometer. In next step technical drawings were created and the whole system was made.
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SELECTIVE EMITOR FOR THERMOPHOTOVOLTAIC SYSTEMS
Šimonová, Lucie ; Hrzina,, Pavel (referee) ; Šály,, Vladimír (referee) ; Vaněk, Jiří (advisor)
The work is focused on research and development of a suitable method for creating a selective emitter for the visible and near infrared region so that they are able to work optimally together with silicon photovoltaic cells in a thermophotovoltaic system. The aim of the work was to develop a new method of creating very fine structures outside the current standard, which will increase the emissivity of the base material to meet the needs of a selective emitter for the VID and NIR region. The methods available to us for the creation of structures were chosen, from which we eliminated all unsuitable ones and we introduced the optimal procedure and parameters for their creation for the selected method. In this work, we focused on both ceramic and metallic materials, whose heat resistance and selective properties are key to this work. Part of the development of the emitter structures was also the need for pretreatment of the substrate itself, where great emphasis was placed on the purity of materials and surface roughness. Since ceramic materials cannot achieve a surface roughness so low that the desired structures can be formed, these materials have been purposefully used primarily for the purpose of combining the base material with thin layers of other high temperature material. Their compatibility and suitability were verified in terms of adhesion and subsequent heat resistance. The main material for the formation of fine structures was purposefully chosen tungsten, for which we verified the influence of the formed structure on the emissivity as well as the thermal stability during long-term exposure to high temperatures. The work thus represents not only a new method of creating very fine structures, which are not normally formed in such subtlety, but also opens the way to new possibilities of combining more materials to achieve the required selectivity of the thermophotovoltaic emitter.
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SMV-2019-05: Phase grids
Krátký, Stanislav ; Matějka, Milan ; Chlumská, Jana ; Horáček, Miroslav ; Kolařík, Vladimír ; Meluzín, Petr ; Král, Stanislav
Development of phased gratings manufacturing for use in transient grating spectroscopy. Possible approaches for phased gratings design were studied during the development to achieve the maximum efficiency for two different wavelengths. Theoretic simulations showed that the grating has to be adjusted for the value of wavelength (the depth of the grating) between two desired values of wavelength to achieve the maximum efficiency in first diffractive orders. The samples were manufactured with use of e-beam lithography and reactive ion etching.
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SMV-2019-04: Large-area nanostructures preparing
Horáček, Miroslav ; Kolařík, Vladimír ; Matějka, Milan ; Krátký, Stanislav ; Chlumská, Jana ; Meluzín, Petr ; Král, Stanislav
The development of sandwich nanostructures on doped silicon substrate. The dimension of nanostructures and their pitch is very close to the capability of used e-beam system Raith EBPG5000+. Thin silicon nitride layer was prepared on doped silicon substrate. This layer is needed for wet etching of silicon. The golden markers needed for direct writing of multiple patterns were prepared by the way of e-beam lithography and vacuum evaporation. Mask in the resist layer was exposed for etching of the silicon nitride mask by reactive ion etching in the next step. Wet etching of silicon was carried out after the mask was prepared. Small pyramids were created by the etching process. The last lithography step was preparation of the mask over the pyramids. Thin aluminum layer in the areas where the pyramids are presented was prepared by the way of vacuum evaporation and lift-off technique.
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