National Repository of Grey Literature 199 records found  beginprevious21 - 30nextend  jump to record: Search took 0.01 seconds. 
Sputtering of nitride layers using Kaufman ion-beam source for bioelectronics applications
Jarušek, Jaromír ; Chmela, Ondřej (referee) ; Gablech, Imrich (advisor)
In this work, nitride layers, their applications in bioelectronics, and methods of chemical vapour deposition and physical vapour deposition are presented. The focus of this work is the preparation of titanium nitride thin films by reactive sputtering using Kaufman ion-beam sources. Thin films were deposited on silicon wafers and microslides. Deposited titanium nitride thin films are characterized by X-ray diffraction, four-point probe sheet resistance measurement and profilometry to determine residual stress.
Surface topography of plasma polymers deposited on flat and fibrous substrates examined by atomic force microscopy
Kurakin, Yuriy ; Pálesch, Erik (referee) ; Čech, Vladimír (advisor)
This bachelor thesis deals with the characterization of the morphology of thin films of plasma polymers, which were prepared from the monomer tetravinylsilane and deposited on planar silicon substrates and type E glass fibers. Plasma enhanced chemical vapor deposition (PE CVD) has been used as a method of thin films preparations. Characterization of the surface morphology was made by using atomic force microscopy (AFM), for which was prepared literature review at the theoretical part of this bachelor thesis. The collected data have been used for estimating dependence of surface topography in relation to the deposition conditions and the size of investigated area. Also have been suggested methods of the data interpretation for purposes of subsequent statistical analysis.
Chemical analysis of a-CSi:H and a-CSiO:H films
Olivová, Lucie ; Franta, Daniel (referee) ; Čech, Vladimír (advisor)
Plasma-enhanced chemical vapor deposition is a promising technology for the preparation of materials in the form of thin films with controlled physical-chemical properties, which can be affected by changing input precursors or deposition conditions as needed. In this thesis, plasma nanotechnology was used to synthesize thin films on silicon wafers. Tetravinylsilane was chosen as a precursor for the synthesis of the films. In addition to pure tetravinylsilane, mixtures of tetravinylsilane with argon and mixtures of tetravinylsilane with oxygen were also used as input precursors for film deposition, in different proportions of the individual component in the deposition mixture. Using chemical analyses, specifically infrared spectroscopy, photoelectron spectroscopy and selected ion techniques, the chemical structure of the prepared films was examined in detail and the dependence of this structure on deposition conditions and input precursors was studied. This thesis confirms, that by changing effective power supplied to the plasma discharge and selecting different input precursors, it is possible to control chemical structure, and thus the properties of the prepared nanolayers.
Surface morphology of a-CSi:H films prepared from tetravinylsilane in low-temperature plasma
Křípalová, Kristýna ; Pálesch, Erik (referee) ; Čech, Vladimír (advisor)
This bachelor thesis is focused on the surface morphology of a-CSi:H films. Films were prepared by plasma-enhanced chemical vapor deposition (PECVD) on silicon wafers using plasma discharge. Tetravinylsilane (TVS) precursor was used for deposition. The set of samples deposited at different effective power (2-150 W) and a thickness of about 0.6 µm was characterized to investigate their surface properties. Atomic force microscopy was used for characterization of surface morphology. Obtained results were used for evaluation of surface roughness and assessment of the effect of the film growth dynamics on the surface topography.
Advanced Materials for Organic Photonics
Ouzzane, Imad ; Táborský,, Petr (referee) ; Lukeš,, Vladimír (referee) ; Weiter, Martin (advisor)
V oblasti nových nízkomolekulárních organických materiálů patří deriváty difenyldiketopyrrolopyrrolu (DPP), používané dříve jako barviva a pigmenty, k objektům vysokého zájmu pro jejich potencionální aplikace v moderních technologiích. Studium jejich optických vlastností ve vztahu k jejich chemické struktuře umožní využití jejich vysokého potenciálu ve vývoji pokročilých inteligentních materiálů. Přehled chemických a fyzikálních vlastností DPP derivátů a zhodnocení současného stavu řešené problematiky jsou uvedeny v teoretické části této práce. Tři hlavní procesy studované v této práci jsou: klasická absorpce a emise, dvoufotonová absorpce (TPA) a zesílená spontánní emise (ASE). Výsledky budou diskutovány a shrnuty ve dvou částech: první zahrnuje první dvě výše zmíněné oblasti a druhá problematiku zesílené spontánní emise.
Selective growth of GaN nanostructures on silicon substrates
Knotek, Miroslav ; Novák, Tomáš (referee) ; Voborný, Stanislav (advisor)
This thesis deals with deposition of gallium nitride thin films on silicon substrates covered by negative HSQ rezist. Rezist was patterned via electron beam lithography to create masks, where the selective growth of crystals was achieved. Growth of GaN layers was carried out by MBE method. For achievement of desired selective growth, the various deposition conditions were studied.
Surface topography of a-CSi:H films deposited by continuous wave PECVD
Blažková, Naďa ; Pálesch, Erik (referee) ; Čech, Vladimír (advisor)
The thesis describes surface topography of a-CSi:H films deposited by continuous wave plasma enhanced chemical vapor deposition (PECVD) based on tetravinylsilane monomer (TVS). Thin films are completely used in many fields of modern technologies and their physical and mechanical properties are affected by thin film preparation techniques. In this thesis the thin films were deposited by PECVD method on silicon wafers with the pure TVS monomer. Deposited samples were topographically described and analyzed using atomic force microscopy (AFM). The main characteristics which were described are RMS roughness, autocorrelation function and a size distribution of grains on the thin film surface. Analysis was realized with two sets of samples with different powers and thickness. The main results were statistically evaluated like a mixture of object on the surface prepared in different deposition conditions.
Fabrication of transparent oxidic conducting coatings by material printing
Žáková, Michaela ; Krystiník,, Pavel (referee) ; Dzik, Petr (advisor)
Thin transparent conductive layers containing ATO nanoparticles are a modern material that has found use in a wide range of optoelectronic applications. For liquid phase deposition there were designed and prepared compositions using a „brick and mortar“ approach combined templating agents. A sol-gel solution formed of inorganic precursors of tin chloride and antimony trichloride in the presence of ATO nanoparticles was mixed with a surfactant to improve the structure and wettability of applied films. Polyethylene glycol, polyoxyethylene (20)cetylether, sodium dioctylsulfosuccinate and polyvinylpyrrolidone were used as templating agents. Thin layers of these compositions were applied by the spin-coating method. Characterized parameters were resistivity, thickness and turbidity. A resul compositions showed relatively good electrical properties and high transparency and a potencial to be used for material printing.
Poly-para-xylylene films preparation and characterization of their properties
Menčík, Přemysl ; Salyk, Ota (referee) ; Přikryl, Radek (advisor)
Poly-p-xylylene is a basic polymer of parylene family. It was discovered in 50s of the 20th century. In practical applications, there are used several derivates. Most of them are discussed in this thesis. Poly-p-xylylene has many utility properties, like barrier, thermal and mechanical properties. It can be used for conservation and protection of electronic equipments, medical tools and devices or museum exhibits. The most important property of parylene is its low dielectric constant which enables parylene to have good insulating properties in form of very thin layer. The most common precursor used for parylene coatings by Chemical Vapor Deposition (CVD) is [2,2]paracyclophane. Special device invented for this process was described in this thesis, including every part and assembly. The main aim of this thesis was to test properties of thin parylene layers on metal samples. High degree of polymer crystallinity was confirmed by confocal laser microscopy and optical microscopy in the polarized light measurements. Problems in the conventional method of production of parylene layers were found during the measurement of thickness of layers. Purity of deposited films was determined using Infrared spectroscopy (IR). Parylene barrier properties were quantified by the measurement of Oxygen Transmission Rate through a layer deposited on the surface of PP foil. Because the research has been mainly focused on protection of museum exhibits, the corrosion resistance test is the most important. Metal samples with thin parylene film were compared to samples with conventional restoration coating. The samples with parylene protection were slowly corroded by point corrosion. In contrast to them, the samples conserved by conventional restoration method were almost destroyed by corrosion.
Chemical structure of silicon-based thin films
Olivová, Lucie ; Franta, Daniel (referee) ; Čech, Vladimír (advisor)
This bachelor thesis deals with the characterization and preparation of thin polymer films deposited on silicon wafers by plasma-enhanced chemical vapour deposition. The main part of the work is background research in the field of plasma polymerization and infrared spectroscopy. Thin polymer films based on tetravinylsilane and tetravinylsilane with the addition of mixed gas (argon) were prepared in the experimental part. The prepared thin films of plasma polymers were characterized by the selected spectroscopic technique - infrared spectroscopy. Based on the evaluation of transmission infrared spectra, the chemical structure of the deposited polymer films was determined. The determined chemical structures of the prepared films were observed with respect to the deposition conditions and hence the possibility to prepare tailored films for a variety of applications.

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