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Organic solid state lasers
Koutný, Jan ; Salyk, Ota (referee) ; Vala, Martin (advisor)
The aim of this thesis is the preparation and characterization of model components for organic thin-film solid-state lasers. The theses focuses on comparing different methods of determining the threshold energy, which leads to an amplified spontaneous emission of the studied derivative diketo-pyrrolo-pyrrole. The theoretical part is devoted to a summary of knowledge on the interaction of light with matter and lasers with a focus on organic solid-state lasers. The practical part is focused on preparation of model components for organic solid-state lasers, modification of apparatus for their characterization, comparison of evaluation methods for determining the threshold energy and study of the effect of different conditions of components preparation.
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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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Sensoric properties of organic N-type semiconductors and their air stability
Saska, Pavel ; Vala, Martin (referee) ; Salyk, Ota (advisor)
Hydrogen has been for some time discussed as a successor to fossil fuels whose stocks are constantly running low. One of the crucial requirements for the possible usage of hydrogen as an energy carrier is our ability of reliable detection. In context with development of organic electronics there occurred a possibility to use derivatives of diketopyrrolopyrroles as sensing materials of hydrogen sensors. Derivatives of diketopyrrolopyrrole are organic pigments that behave as semiconductors. Their analogues with pyridyl side group are due to free electron pairs of nitrogen atoms sensitive to hydrogen. The problem of organic N-type semiconductors is in general their instability on the air. This thesis is focused on testing of hydrogen sensors with active layer made from derivatives of diketopyrrolopyrrole and judging their stability on the air.
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Plasma-enhanced chemical vapor deposition using TVS/Ar and TVS/O2 mixtures
Sadílek, Jakub ; Salyk, Ota (referee) ; Čech, Vladimír (advisor)
Tato studie je zaměřena na základní výzkum přípravy a-SiC:H a a-SiCO:H slitin plazmových polymerů pomocí metody plazmochemické depozice z plynné fáze (PE-CVD). Tyto slitiny byly připravovány depozicí z monomeru tetravinylsilanu (TVS) a jeho směsí s kyslíkem a argonem při různých efektivních výkonech pulzního plazmatu. Připravené tenké vrstvy byly za účelem získání závislostí optických, mechanických a chemických vlastností na depozičních podmínkách zkoumány pomocí metod spektros-kopické elipsometrie (ELL), nanoindentace (NI), fotoelektronové spektrometrie (XPS) a Fourierovy transformované infračervené spektrometrie
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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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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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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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Preparation of organic semiconducting thin films by vacuum evaporation
Schön, Martin ; David, Jan (referee) ; Salyk, Ota (advisor)
This thesis deals with preparation of organic molecular thin film compounds and its properties like morphology and purity. The vapour deposition was used for thin films preparation, because used materials are very few soluble. Thin films properties were characterized with the infrared spectroscopy (FTIR) and scanning electron microscope. There are described basics of infrared spectroscopy, spectra measurement and interpretation in the theoretical part. Process of thin film preparation is also described in this part. In the experimental part are described used vacuum technology and measuring instruments, process of sample measurement and there is the list of studied materials. 12 derivates of diketopyrrolopyrrols (DPP) were studied in this thesis. Diketopyrrolopyrroles (DPP) and its derivates have interesting chemical and physical properties, expecting wide range of applications, especially in electronics industry.
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Analysis of x-ray diphractograms of organic crystalline solids
Stejkora, Jakub ; Žídek, Jan (referee) ; Salyk, Ota (advisor)
Derivates of diketopyrrolopyrrole are colored pigments with potential use in field of organic semiconductor structures. Their electrical attributes such as conductivity, photocon¬¬ductivity and electroluminescence relate to their crystal structures that determine charge transport path through the compound. For crystallographic structure determination from RTG diffractometry it is needed to grow a measurable single crystal. Growing crystals of derivates of diketopyrrolopyrrols is very difficult due to their poor solubility in all solvents. Several relatively suitable – perhaps even measurable – samples were obtained throughout the testing of series of methods. One of these samples was measured with RTG diffractometry and on the ground of this measurement it was possible to find and solve the crystallographic structure.
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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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