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Plasma-enhanced chemicial vapor deposition
Žák, Luboš ; Salyk, Ota (referee) ; Čech, Vladimír (advisor)
Theoretical part of diploma thesis was focused on the search of the state of knowledge in the area of plasma, plasma polymerization and characterization of thin films. Plasma-enhanced chemical vapor deposition (PECVD) was described in the experimental part together with selected analytical techniques. The technology with high level of reproducibility was reached by precise control of deposition conditions, monitoring of plasma, and analysis of plasma products using mass spectrometry. The obtained results demonstrated that the elemental composition, chemical structure, optical and mechanical properties of films were influenced by effective power used.
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Printed Biosensor Based on Organic Electrochemical Transistor
Omasta, Lukáš ; Mikula, Milan (referee) ; Boušek, Jaroslav (referee) ; Salyk, Ota (advisor)
Organické elektronické zariadenia sú vyvíjané ako vhodné riešenia senzorov pre bioelektroniku, a to najmä kvôli dobrej biokompatibilite organických polovodičov v nich použitých. Takzvané biosenzory dokážu premeniť elektrochemické procesy na elektronický signál. Matrica takýchto biosenzorov môže simultánne skenovať množstvo biologických vzoriek, alebo rôznych tkanív v živých systémoch. Aktívnou súčasťou zariadenia je organický elektrochemický tranzistor (OECT). V tejto práci je diskutovaný teoretický rámec fungovania takéhoto zariadenia, jeho elektrická charakterizácia, aplikácia v biosenzoroch na báze buniek, spôsoby výroby a aktuálnym stavom techniky v oblasti organickej elektroniky. Experimentálna časť obsahuje konkrétne výrobné postupy vývoja OECT zariadení, ktoré boli použité v našom laboratóriu. Hlavný dôraz sa kladie na schopnosť vyrobených zariadení detekovať reakciu a monitorovať stimuláciu elektrogenných buniek. Za týmto účelom boli vyvinuté matice mikroelektródových OECT zariadení založených na polovodivom polyméri PEDOT:PSS. Tieto boli vyrobené s využitím bežnými tlačiarenských techník (atramentová tlač a sieťotlač) spolu so štandardnými litografickými postupmi. Najnovšie nami vyvinuté zariadenia dosahujú najväčšieho zosílením signálu, g = 2,5 mS a časovú konštantu t = 0,15 s. Tieto zariadenia sú porovnateľné, často dokonca lepšie ako niektoré iné najmodernejšie a plne litograficky pripravené senzory.
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Deposition and characterization of low molecular thin films for organic photonics
Omasta, Lukáš ; Salyk, Ota (referee) ; Weiter, Martin (advisor)
This diploma thesis is focused on characterization of properties of new organic materials with respect to its potential application in organic photonics. The theoretical part contains a themed literature research on low molecular thin films for organic photonics, mainly phthalocyanines together with description and structure of the photovoltaic energy conversion. The practical part includes the preparation of thin layers of selected organic materials for organic photonics. Prepared thin films were characterized by optical methods and current voltage characteristics. Based on these results, the thin films and structure of solar cells were optimalized. Acquired data were used to determine the materials and structures suitable for photonics applications.
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Modelling of bioelectronic devices
Truksa, Jan ; Vala, Martin (referee) ; Salyk, Ota (advisor)
Tématem této práce je počítačové modelování organického elektrochemického tranzistoru (OECT). Pro vytvoření modelu bylo třeba vypočítat rozložení elektrického pole a koncentrace iontů elektrolytu. Výpočet byl proveden numericky pomocí metody konečných prvků. Bylo vypočítáno rozložení elektrického potenciálu na povrchu kanálu OECT, dále byly vypočítány změny vodivosti a výstupní proud OECT. Výpočty byly provedeny na osobním počítači pomocí komerčního softwaru COMSOL Multiphysics. Kvůli nedostatečnému výpočetnímu výkonu musel být model rozdělen na části a drasticky zjednodušen. Prezentované výsledky se liší od literatury, protože se nepodařilo správně modelovat saturaci tranzistoru. Odchylky od reálného chování OECT jsou pravděpodobně způsobeny zjednodušením modelu.
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Low-molecular materials for organic electronics and photonics
Češka, Matěj ; Salyk, Ota (referee) ; Weiter, Martin (advisor)
This master´s thesis deals with organic materials for use in electronics and photonics. Attention was paid to low molecular weight materials. The theoretical part of this thesis contains brief introduction to organic electronics and photonics. In particular, organic transistors, organic solar cells and organic light-emitting diodes are mentioned. The experimental part is focused on study of electrical and optical properties of two types of phthalocyanines. Thin films and solutions of phthalocyanines were characterized by UV-VIS spectroscopy. Thin films were also characterized by current voltage characteristics, spectral response measurement of photocurrent and by method of transient photoconductivity. It was found that illumination affects the electrical properties of thin layers of phthalocyanines, the performance of the prepared thin films depends on the type phthalocyanine and also depends on the thickness of the layer.
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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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Thin plasma polymer films on metal substrates
Mach, Pavel ; Salyk, Ota (referee) ; Přikryl, Radek (advisor)
The theoretical part of the thesis is focused on surface treatments, their evaluation from the point of view visual properties, plasma-enhanced chemical vapor deposition and analysis of thin layers prepared by plasma polymerization. The experimental part of the thesis deals with surface treatment of stainless steel AISI 304. Thin layers of pp-HMDSO (plasma-polymer) and of DLC are deposited on the steel´s surface for the purpose of preparing transparent layer, which protect steel´s surface against of making finger prints visible. As an objective method is chosen an immersion test in artificial sweat solution according to standard ČSN EN ISO 105-E04. Evaluation of the test is measured by a gloss-meter and by a colorimeter. Prepared layers are identificated by FTIR method.
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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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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.
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