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Testing and optimization of an ion source
Glajc, Petr ; Král,, Jaroslav (referee) ; Kolíbal, Miroslav (advisor)
A thorough description of the testing of a saddle-field ion source is presented in the diploma thesis. The most important experimental results, such as Faraday cup measurements of the ion beam current profile and of the ion energy spectra, are included. Based on these results it is shown that the optimized ion source works correctly and according to the expectations. At the end of the thesis, the development of the ion-optical and construction design of the focusing optics is described. The manufactured optics assembly attached to the ion source is also shown.
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Applications of nanotechnology in detection of biomolecules
Váňa, Rostislav ; Skladal,, Petr (referee) ; Kolíbal, Miroslav (advisor)
This thesis deals with metal nanostructures and their use in detection of biomolecules. A protocol for stabilizing solutions of gold nanoparticles was developed for better usage in biological samples or biochemical processes, where different pH or salt concentrations can be used. A model of optical properties of the nanoparticles was presented and supported by spectroscopic experiments. A possible utilization of plasmonic nanostructures on surfaces for detection of biomolecules was also demonstrated.
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Modification of semiconductor nanowire growth
Pejchal, Tomáš ; Grym, Jan (referee) ; Kolíbal, Miroslav (advisor)
This diploma thesis deals with the growth of semiconductor nanowires on Ge(111) surface. The nanowires were prepared by means of PVD (physical vapor deposition). The growth was calatyzed by Au colloidal nanoparticles. An impact of different growth conditions on nanowire morfology is presented. It is demonstrated that Ge nanowires grow preferentially along axis. Ge wires with orientation were observed as well.
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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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Design and Testing of methodology for in-situ sample cleaning for low voltage electron microscopy
Rudolfová, Zdena ; Vávra,, Ivo (referee) ; Kolíbal, Miroslav (advisor)
This thesis concentrates on the methodology of semiconductor samples preparation for low voltage scanning electron microscopy. In the first part a detailed theory of sample imaging using electron beam and difference between classical scanning electron microscopy (SEM) and low voltage scanning electron microscopy (LVSEM) is described. It is given a description of a contrast formation in SEM and LVSEM and theories describing a contrast formation of differently doped semiconductors. The second part contains experimental data. The advantages and disadvantages of cleavage and focused ion beam (FIB) milling as sample preparation techniques are discussed. FIB was found as the best method for sample preparation for the analysis of precisely defined location on the sample. It is necessary to use the lowest possible FIB accelerating voltage for final polishing, ideally 1 kV.
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Electrochemical preparation of fluorescence sensor with highly ordered nanostructured surface
Bedlek, Marek ; Kolíbal, Miroslav (referee) ; Drbohlavová, Jana (advisor)
This work deals with fabrication and examination of optical properties of self-ordered TiO2 and Au quantum dots array and its potential usage in medicine as optical sensor for biomolecules detection. Controlled anodization of Ti through Al2O3 template was chosen as a fabrication method for TiO2 QDs, in case of Au galvanic deposition through Al2O3 template onto beforehand prepared TiO2 QDs or substrate with dimple structure. The influence of anodization and deposition conditions on the final structure of QDs and their emission spectrum is also examined.
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Preparation and application of metal and semiconductor nanostructures
Hrubý, Jakub ; Kolíbal, Miroslav (referee) ; Šimšíková, Michaela (advisor)
Tato práce se zabývá teoretickými základy přípravy, charakterizace a možnými aplikací nanostruktur. V experimentální části je nastíněna syntéza a charakterizace nanostruktur. Ušlechtilé kovy jsou zastoupeny zlatem a stříbrem. Oxid zinečnatý jakožto II--VI polovodič a kompozit oxidu zinečnatého a oxidu měďnatého byly také syntetizovány bottom-up metodou. Připravené částice tvořily různé tvary, jako například kuličky, tyčinky, dlaždičky a takzvané nanokytičky. Částice byly posléze charakterizovány. Optickou mikroskopií byl proveden přibližný odhad morfologie. Skenovací elektronový mikroskop byl použit pro detailní pohled do struktury vzorku. Další charakterizační metody jako fotoluminiscence a absorbance byly využity u CuO/ZnO kompozitu.
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Electroless selective deposition of silver nanoparticles
Salajková, Zita ; Bartoš, Miroslav (referee) ; Kolíbal, Miroslav (advisor)
Silver nanoparticles have a widespread use in the field of plasmonics. Since deposition of nanoparticles from colloidal solutions onto an exact location on a substrate is difficult, it seems advantageous to grow the nanoparticles in-situ. The presented work is focussed at selective deposition of~silver nanoparticles from colloidal solution or from solution reach of silver ions under assistance of focussed electron beams. Successful deposition could lead to growth of well defined nanostructures directly at the substrate surface. The effect of electron beam intensity to surface quality is studied (silica reduction, surface morphology) as well as effect of pH to particle properties. Outputs are used as a part in theoretical description of selective deposition and confirmed by following advanced experiments. The light assisted deposition and growth of nanostructures is described at the end of the presented work.
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Passivation of germanium surface using ALD
Kuba, Jakub ; Polčák, Josef (referee) ; Kolíbal, Miroslav (advisor)
The thesis deals with passivation of germanium surfaces by chemical etching and atomic layer deposition (ALD). Attention was paid to the rate of oxidation of germanium surfaces after selected passivation methods and the composition of the germanium suboxides. In the thesis selected methods for germanium oxide removal are reviewed and a brief description of the methods used for analysis (XPS) and thin film deposition (ALD) is given.
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