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Thin films prepared in RF glow discharge and their physico-chemical properties
Bránecký, Martin ; Boušek, Jaroslav (referee) ; Čech, Vladimír (advisor)
Theoretical part of this master thesis was focused on literature recherché dealing with the formation of thin films, plasma, plasma analyses using mass spectrometry and plasma polymerization. Further, this section describes the analysis of thin films using optical methods such as spectroscopic ellipsometry and FT-IR spectrometry. Experimental part describes the materials which are used for the preparation of thin films as well as a description of the equipment for preparation of thin films using a technology of plasma-enhanced chemical vapor deposition (PE-CVD). Control of deposition conditions and monitoring of plasma with its products result in high reproducibility of thin films. The last part of the thesis describes the results of measurement of the first group of samples and their ellipsometric, mass spectrometry and FT-IR evaluation with respect to the deposition conditions.
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Study of optical properties of thin films of perovskiteFAPbBr3 precursors
Smolková, Denisa ; Čech, Vladimír (referee) ; Zmeškal, Oldřich (advisor)
This thesis examines the preparation of thin layers of material for photovoltaic applications with focused on perovskites and determining their optical properties. Basic information about the photovoltaic panels, especially about the perovskites, and the preparation of thin layers is supplied in the theoretical section. This section includes description of optical properties and the main method of study of optical properties, spectroscopic ellipsometry. Experimental section is focused on the preparation of thin layers of perovskites FAPbBr3 and its precursors by spin-coating. Optical properties are evaluated using profilometry, UV VIS spectrometry and spectroscopic ellipsometry. The conclusion summarizes the results of this experiment with focused on comparison of ellipsometric spectrums of perovskites and its precursors.
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Ellipsometry of Thin Films
Novotný, Zbyněk ; Navrátil, Karel (referee) ; Nebojsa, Alois (advisor)
Diploma thesis deals with ageing process of thin films of Co and Cu on Si substrate, prepared by the IBAD method. The process of film ageing, which depends on time of exposition to the atmosphere at room conditions, was investigated with spectroscopic ellipsometry (VIS+UV) and atomic force microscopy. In case of thin Co films, approximately four days long incubation period was observed. During this time period, a change in the optical parameters of the film occurs without a measurable change of the film topography. Using non-contact atomic force microscopy, a growth of the transitional film in the island growth regime was observed. During the ageing of thin Cu films, two stages of growth of the transitional layer were observed - nucleation stage and growth stage. Both of these time periods of the transitional layer growth show direct logarithmic dependence. Using non-contact atomic force microscopy, the growth of the transitional film was observed. Using atomic force microscopy in non-contact regime, time dependent measurement was done and the process of forming of one monolayer of the transitional layer was documented. Within the diploma thesis, a series of experiments on ultra high vacuum system were performed in order to investigate phase transformation of thin Fe films (22 monolayers) on Cu(100) stabilized by CO absorption. The transformation from fcc phase to bcc phase was induced by Ar+ ion beam bombardment with the ion energy in the range (0.5-4) keV. The process of phase transformation was observed by surface magneto-optic Kerr effect, Auger electron spectroscopy and low energy electron diffraction.
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Use of biomaterials for optoelectronic applications in semiconductor technology
Čuboň, Tomáš ; Salyk, Ota (referee) ; Zmeškal, Oldřich (advisor)
The bachelor´s thesis is aimed to measurement optical properties of thin layer films of biomaterials which could be used in optoelectronics and semiconductor technology. DNA and BSA were chosen in order to represent such extensive group of biomaterials. The theoretical part describes the way of preparation of thin layer. It also provides some information about basic phenomena and biomaterials. The practical part is focused on the description of preparation of thin layer film using spin-coating method. The chosen materials were studied by optical microscopy, UV-VIS spectrophotometry and spectroscopic ellipsometry. The thickness of prepared samples was measured by mechanic profilometry. In the last section of the bachelor´s thesis, there is discussion and evaluation of results.
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Study of the optical properties of titanium dioxide thin films
Rackovská, Anna Patrícia ; Schmiedová, Veronika (referee) ; Zmeškal, Oldřich (advisor)
The bachelor thesis is focused on the acquirement of thin film layers optical properties characterisation methods, done on inject printed titanium dioxide layers deposed on soda lime glass. Its main emphasis was on spectroscopic ellipsometry that was used to determine the refractive indices and the extinction coefficients of the samples in range of wavelengths from 200 nm to 850 nm and layer thickness. This thesis also shows another options of thin film layers preparation and several other methods to characterise properties of samples, specifically optical microscopy, used to set sample boundary as rough, mechanical profilometry which defined thickness of layers in range of 80 nm for the most thin sample to 250 nm for the most thick sample, and UV-VIS spectroscopy.
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Adhesion of a-SiOC:H films on planar substrates
Lepcio, Petr ; Salyk, Ota (referee) ; Čech, Vladimír (advisor)
This bachelor thesis deals with preparation of thin films of plasma polymers prepared by plasma-enhanced chemical vapor deposition. Tetravinylsilane was used as a monomer. Two sets of samples were prepared. Samples of the first set were prepared at different effective powers from pure tetravinylsilane and samples of the second set were prepared from deposition mixture of tetravinylsilane with different oxygen content at constant effective power. The film thickness was evaluated by spectroscopic ellipsometry and chemical structure by infrared spectroscopy. A scratch test was used to determine adhesion characterized by the critical normal load. An appearance of performed scratches was obtained by atomic force microscopy (AFM). Film adhesion influenced by the effective power and oxygen content in deposition mixture was discussed based on the received data.
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Study of optical properties of thin films of perovskite MAPbBr3 precursors
Rackovská, Anna Patrícia ; Schmiedová, Veronika (referee) ; Zmeškal, Oldřich (advisor)
This diploma thesis is focused on preparation of perovskite methylammonium lead bromide thin film layers and also thin film layers of its precursors, namely methylammonium bromide and lead(II) bromide, by spin-coating from the solution; and optical characterisation of the prepared thin film layers by UV-VIS spectroscopy and spectroscopical ellipsometry. Methylammonium bromide does not absorb in visible nor ultraviolet region, the maximum absorption of lead(II) bromide occurred in ultraviolet region, methylammonium lead bromide absorbs in visible region. Optical band gaps were determined by Tauc method to (3,5 ± 0,1) eV for lead(II) bromide and 2,15 eV, respectively 2,25 eV for perovskite. Refractive indices and extinction coefficients were determined by ellipsometry in range of wavelengths from 290 nm to 830 nm and their dependence with layer thickness was discussed. Ellipsometry model used in this thesis consist on Tauc-Lorentz oscillators for methylammonium bromide, methylammonium lead bromide and partially for lead(II) bromide, which another part is formed by New Amorphous oscillator.
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Characterization of a new deposition system for coating the fibers
Zvonek, Milan ; Salyk, Ota (referee) ; Čech, Vladimír (advisor)
Cieľom bakalárskej práce je charakterizácia depozičného systému na výrobu tenkých vrstiev. Teoretická časť je zameraná na literárnu rešerš o plazme, plazmovej polymerácií, tenkých vrstvách a ich analýzu pomocou infračervenej spektroskopie a spektroskopickej elipsometrie. Experimentálna časť popisuje použité materiály a aparaturu použitú na prípravu tenkých vrstiev pomocou plazmovej polymerácie. Posledná časť popisuje výsledky merania depozícií tenkých vrstiev a ich vyhodnotenie vzhľadom na depozičné podmienky.
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Ordered and disordered arrays of colloidal nanoparticles for biomolecule detection
Ligmajer, Filip ; Rezek, Bohuslav (referee) ; Kolíbal, Miroslav (advisor)
This thesis deals with guided self-assembly of gold nanoparticles from their colloidal solutions onto silicon substrates and possible employment of nanoparticles for detection of biomolecules. It was found that by adjustment of solution pH and surface chemistry modification by means of electron beam irradiation it is possible to facilitate nanoparticle deposition to patterns with almost single particle precision. Spectroscopic ellipsometry was then employed in analysis of self-assembled layers of nanoparticles and its combination with a theory of effective medium approximation has proven the ability to assess nanoparticle dimensions and volume fractions. By experiments with thiolated oligonucleotides it has been shown that using ellipsometry one can detect even with very subtle changes in nanoparticle environment caused by biomolecules, thus promising its possible use in the field of biodetection.
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Synthesis of low-crosslinked polymers by plasma polymerization
Kuchtová, Štěpánka ; Bránecký, Martin (referee) ; Čech, Vladimír (advisor)
This bachelor thesis deals with plasma enhanced chemical vapour deposition (PECVD), specifically plasma polymerisation, which has been used for the synthesis of low density crosslinked polymer thin films. Organosilicon thin films were deposited on a silicon substrate by radio frequency (RF) capacitively coupled plasma in a deposition chamber. Spectroscopic ellipsometry was used to determine the layer thickness and its optical properties. The chemical structure of the layers was investigated by Fourier transform infrared spectroscopy and the mechanical properties were investigated by nanoindentation. The effect of power and self-bias (USB) on the chemical structure, mechanical and optical properties of the as-prepared layers, which are related to the crosslinking density, was investigated in the context of achieving low crosslinking density of the material. Low crosslinked plasma polymers were synthesized at a self-bias level of 1 V, which corresponds to an approximate RF power of 0,1 W. This material can be characterized by a density of 1, 2 g·cm-3 an elastic modulus of 4 GPa, a hardness of 0,04 GPa and a refractive index of 1.53 at 633 nm (He-Ne laser wavelength). Infrared spectroscopy confirmed that this plasma polymer is composed of a carbon network with fewer embedded silicon atoms and, in particular, the highest concentration of vinyl groups compared to plasma polymers prepared at higher powers.
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