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Characterisation of dielectric films on a silicon wafer
Fillner, Patrik ; Boušek, Jaroslav (referee) ; Hubálek, Jaromír (advisor)
This bachelor thesis focuses on thin oxide based dielectric layers on silicon wafer. Main effort is for characterization of properties of samples. This technology can be used for manufacturing capacitors on silicon chips. Samples are based on planar oxide layers made with thin film technology on single silicon wafers coated with electrodes deposited by evaporation or by sputtering.
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Preparation of nanostructures using nanoporous template
Dzuro, Matej ; Hrdý, Radim (referee) ; Drbohlavová, Jana (advisor)
The aim of the work described in this paper is to prepare electrochemically an optical sensor consisting of TiO2 quantum dots (QDs) using nanoporous Al2O3 template in the first step and to modify the surface of QDs with gold layer by evaporation process, again using nanoporous template, in the second step. This easy, cheap and rapid approach provides homogenous and highly ordered distribution of both nanostructures on substrate. The final objective is to characterize the physical parameters and fluorescent properties of TiO2/Au sensor designed for optical detection of biomolecules such as DNA and proteins.
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Electrical characteristics of graphene layers and their use as gas sensors
Kučera, Štěpán ; Kaspar, Pavel (referee) ; Macků, Robert (advisor)
This bachelor thesis focuses on the general characterization and description of graphene and related nanostructures. It involves production by the most used methods, including their advantages and disadvantages. Due to the impossibility of connection in the usual way, the graphene sample had to be contacted under visual inspection with a microscope with the tip contacts in the shielded area. Subsequently, it was subjected to current-voltage characterization with normal conditions on a Keithley 4200-CSC instrument. The next step was to measure the same sample under a different gas atmosphere. The result is a comparison of the specific responses to the change in gas atmosphere in which the graphene monolayer was exposed.
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Temperature drift compensation for nanostructure analysis
Hakira, Stanli ; Páleníček, Michal (referee) ; Bábor, Petr (advisor)
An ultra high vacuum apparatus for nanostructure experiments is being developed by the Tescan company in cooperation with the Institute of Physical Engineering of the Faculty of Mechanical Engineering. The apparatus is designed for preparation, modification, and analysis of nano-scale structures. A sample holder which allows heating and cooling has been developed for the apparatus. A scanning electron microscope is attached to the chamber to provide analytical and manufacturing capabilities. During experiments with heating enabled, the sample moves relative to the SEM column, causing drift of the image. This bachelor thesis proposes a solution to the problem of temperature drift by the means of motion tracking based on image registration using Fourier transform. An application complementary to the SEM control software which implements the algorithm was designed and tested at the instrument.
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Porous-alumina-assisted formation of metal and metal-oxide nanostructures for use in advanced micro-devices
Kamnev, Kirill ; Mardare, Andrei Ionut (referee) ; Blanchar, Xavier Correig (referee) ; Mozalev, Alexander (advisor)
Anodizace kovů přes masku porézní anodické aluminy (PAA) je použita namísto nanoporézní anodizace nebo tradičních nanofabrikačních metod na výrobu nových nanostrukturovaných oxidů kovů se zdokonalenými parametry. Vylepšování vlastností oxidů ZrO2 a HfO2 nanostrukturováním vzbuzuje podstatný zájem kvůli aktivní komercionalizaci těchto oxidů kovů. Nanostrukturování ZrO2 a HfO2 anodizací je náročné kvůli včasné krystalizaci anodického oxidu a téměř nulovému transportnímu číslu kationtů. Tyto problémy jsou řešeny systematickým zkoumáním anodického chování dvouvrstev složených z tenké vrstvy Al nadeponované na vrstvě Zr nebo Hf. Po prvý krát je dosažen reprodukovatelný růst ZrO2 nanostruktur přes masku PAA, které plní póry PAA masky jenom částečně. Tyto vnořené ZrO2 nanostruktury se projevují zlepšeným dielektrickým výkonem v širokém rozsahu frekvencí s nízkými zbytkovými proudy a vysokými hodnotami průrazného napětí. Tyto vlastnosti z nich dělají atraktivní struktury pro použití v mokrých a hybridních elektrolytických kondenzátorech. Vrstvy s rovným povrchem, kompatibilní se standardními metodami nanofabrikace a obsahující ZrO2 nanostruktury kompletně plnící póry PAA masky, jsou syntetizovány kombinací anodizace přes masku PAA s částečným rozpuštěním PAA. Tyto vrstvy jsou použity v experimentálních MIM mikrokondenzátorech, které vykazují nízké zbytkové proudy, vysoké hodnoty průrazného napětí, vysoké hustoty energie, nízké hodnoty teplotního koeficientu kapacity a výbornou linearitu mezi kapacitou a napětím, což z nich dělá dokonalé kandidáty pro pasivní integraci zařízení na čipu. ZrO2 nanovrstvy připraveny anodizací přes masku PAA jsou, po prvý krát, schváleny k produkci osteogenních biokeramických povlaků. Tyto nanostrukturované biokeramické ZrO2 povlaky mohou modulovat interakce mezi buňkami a povrchem a zvyšovat mineralizaci osteoblastů 5 krát oproti rovné anodické ZrO2 vrstvě. Nanostrukturované HfO2 vrstvy připraveny anodizací přes masku PAA vykazují opakovatelné nízkovýkonové bipolární rezistivní spínání, což je dělá význačnými jako tuhé elektrolyty pro aplikace v memristorech. Anodizace Hf přes masku PAA v kombinaci s vhodnými chemickými modifikacemi povrchů je použita po prvý krát k vytvoření samouspořádaných nanostrukturovaných HfO2 povlaků, které jsou superhydrofóbní, odpuzují olej, jsou transparentní pro viditelné světlo a antireflexní, což je dělá velmi vhodnými pro pasivaci fotovoltaických zařízení.
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Electrical characteristics of graphene layers and their use as gas sensors
Kučera, Štěpán ; Kaspar, Pavel (referee) ; Macků, Robert (advisor)
This bachelor thesis focuses on the general characterization and description of graphene and related nanostructures. It involves production by the most used methods, including their advantages and disadvantages. Due to the impossibility of connection in the usual way, the graphene sample had to be contacted under visual inspection with a microscope with the tip contacts in the shielded area. Subsequently, it was subjected to current-voltage characterization with normal conditions on a Keithley 4200-CSC instrument. The next step was to measure the same sample under a different gas atmosphere. The result is a comparison of the specific responses to the change in gas atmosphere in which the graphene monolayer was exposed.
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Iron Functionalized Nanoparticles of Titanium Dioxide
Volfová, Lenka
Diploma thesis Iron Functionalized Nanoparticles of Titanium Dioxide Lenka Volfová 2017, ABSTRACT Iron-functionalized TiO2 were obtained by hydrolysis of aqueous solutions of titanyl sulfate with addition of ferric nitrate with ammonium hydroxide and the reaction filtered and washed with hydrogen peroxide. The colloid solutions thus prepared were lyophilized and the products were subsequently annealed at three different temperatures of 650 řC, 800 řC and 950 řC. The prepared doped materials were characterized by powder X-ray diffractometry, electron microscopy, infrared spectroscopy, Mössbauer spectroscopy, UV/VIS spectroscopy, thermogravimetric analysis and differential thermal analysis, and measurement of the specific surface area. Photocatalytic activity was determined by measuring of the decomposition of kinetics of 4-chlorophenol in an aqueous solution in the ultraviolet and visible area. For comparison of activity in the UV area and in the visible area were used a previously prepared highly photoactive specimen and standard TiO2 from Kronos, respectively. Keywords: Doped titanium dioxide, nanostructure, X-ray diffraction, electron microscopy, Mössbauer spectroscopy, suppression of photoactivity
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Structuring of plasma polymers: new methods for fabrication of nano-architectured thin films
Nikitin, Daniil ; Shukurov, Andrey (advisor) ; Novák, Stanislav (referee) ; Straňák, Vítězslav (referee)
Title: Structuring of plasma polymers: new methods for fabrication of nano-architectured thin films Author: Daniil Nikitin Department / Institute: Department of Macromolecular Physics/Charles University Supervisor of the doctoral thesis: Doc. Ing. Andrey Shukurov, PhD, Department of Macromolecular Physics/Charles University Abstract: The PhD thesis aims at the investigation of nanostructures based on plasma polymers. The main attention is paid to the combination of a gas aggregation cluster source with plasma-assisted vapor phase deposition for the fabrication of metal-polymer nanocomposites with bactericidal potential. Copper nanoparticles were incorporated into a biocompatible matrix of plasma polymerized poly(ethylene oxide) (ppPEO). The efficiency of such nanocomposite against multi-drug resistant bacteria was demonstrated. It was found that the segmental dynamics of the plasma polymer significantly changed in the presence of nanoparticles as revealed by the measurements of the dynamic glass transition temperature. The nanoscale confinement crucially influences the non-fouling properties of poly(ethylene oxide). A separate chapter is dedicated to the examination of the nanoparticle formation, growth and transport inside the source. Copper and silver nanoparticles were detected in situ in the gas phase...
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Multicomponent plasma polymers with spatially controlled properties
Pleskunov, Pavel ; Shukurov, Andrey (advisor) ; Čech, Vladimír (referee) ; Tichý, Milan (referee)
Title: Multicomponent plasma polymers with spatially controlled properties Author: MSc. Pavel Pleskunov Department / Institute: Department of Macromolecular Physics/Charles University Supervisor of the doctoral thesis: Prof. Ing. Andrey Shukurov, PhD, Department of Macromolecular Physics / Charles University Abstract: Mixing of two (or more) polymers often leads to phase separation and to the formation of nanoscale architecture, which can be highly attractive in various applications including controllable drug delivery, fabrication of separation and solid electrolyte membranes, gas storage, etc. Different wet-chemistry techniques already exist to produce nanophase-separated polymers; however, capturing the resultant polymeric structure in a predictable manner remains a challenging task. In this thesis, a low-temperature plasma-based strategy is investigated for the production of multicomponent thin films of plasma polymers with spatially discriminated nanoscale domains. Gas aggregation cluster source is used for the fabrication of nanoparticles of plasma polymerized acrylic acid, whereas Plasma-Assisted Vapor Phase Deposition is used for the deposition of thin films of poly(ethylene oxide) plasma polymer. Embedding of nanoparticles into matrices of thermodynamically incompatible plasma polymer as well as...
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