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Study of electrical and dielectric properties of thin polymer films
Miklíková, Zdeňka ; Novák, Vítězslav (referee) ; Zmeškal, Oldřich (advisor)
The thesis is focused on the study of electric and dielectric properties of thin-film organic materials that can be used as an active layer of photovoltaic cells. Primarily were studied the properties of the layers on the glass substrate, which consist of a thin active layer of mixture ZnPc/PCBM with Al or Au contact. On the selected samples were first measured current-voltage characteristics in the dark and during the exposure then on the selected samples were measured frequency dependences (impedance spectra) in the dark and finally on the selected samples were measured relaxation characteristics (transient response analysis – current dependences on time at constant voltage) in the dark. The measured data for transient measurement were evaluated using the methods of fractal analysis in HarFA. The results will be used to optimize the properties of photovoltaic cells.
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Organic solar cells prepared by methods compatible with printing technologies
Babincová, Kristina ; Pospíšil, Jan (referee) ; Zmeškal, Oldřich (advisor)
The theoretical part deals mainly with basic properties of organic materials, which are used in electronics, and especially in the field of photovoltaic cells. The experimental part deals with preparation of photovoltaic cells by deposition from solution, characterization of their basic electrical properties and preparation of a photovoltaic cell with its own pattern. Samples of classical and inverted structures of photovoltaic cells with P3HT and PCBM bulk heterojunction were prepared. Reference samples were prepared under standard conditions (under nitrogen). Their efficiency was around 3 %. In addition, samples were prepared by spin coating under laboratory conditions and by spreading. In both cases, their efficiency was about 1.5 %. Large-scale photovoltaic cells (active area of about 1 cm^2) were prepared in the last experiment presented. Efficiency decreased to 0.75 %. From results mentioned above is clear that very simple methods and procedures that do not impair the price/performance ratio can be used to prepare photovoltaic cells.
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Organic solar cells prepared by methods compatible with printing technologies
Babincová, Kristina ; Pospíšil, Jan (referee) ; Zmeškal, Oldřich (advisor)
The theoretical part deals mainly with basic properties of organic materials, which are used in electronics, and especially in the field of photovoltaic cells. The experimental part deals with preparation of photovoltaic cells by deposition from solution, characterization of their basic electrical properties and preparation of a photovoltaic cell with its own pattern. Samples of classical and inverted structures of photovoltaic cells with P3HT and PCBM bulk heterojunction were prepared. Reference samples were prepared under standard conditions (under nitrogen). Their efficiency was around 3 %. In addition, samples were prepared by spin coating under laboratory conditions and by spreading. In both cases, their efficiency was about 1.5 %. Large-scale photovoltaic cells (active area of about 1 cm^2) were prepared in the last experiment presented. Efficiency decreased to 0.75 %. From results mentioned above is clear that very simple methods and procedures that do not impair the price/performance ratio can be used to prepare photovoltaic cells.
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Carbon nanomaterials and their interactions with bacteria
Jurková, Blanka ; Beranová, Jana (advisor) ; Kuthan, Martin (referee)
Recently, carbon nanomaterials gain attention especially for their interesting, often unique, properties. They can be used in wide range of applications, such as electronics, optics, cosmetics, solar cells, construction materials, air filters, polishing materials, protective coatings and dry lubricants. Whereas their physical and chemical attributes have already been intensively examined, the research on their effects on living organisms is still at the preliminary stage. This work is focused on the interactions of carbon nanomaterials, namely graphene, fullerene, carbon nanotubes and nanodiamonds, with bacterial cells and their antibacterial and antiadhesive properties. The mechanisms of the toxic action of carbon nanomaterials against bacteria include damage of outer cell structures as a consequence of the direct contact with a nanomaterial, impairment of bacterial metabolism or reactive oxygen species production. Exact understanding of the processes that take place between bacterial cell and carbon nanomaterials can contribute to the research on their medical applications and ecological recycling in the future.
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Study of electrical and dielectric properties of thin polymer films
Miklíková, Zdeňka ; Novák, Vítězslav (referee) ; Zmeškal, Oldřich (advisor)
The thesis is focused on the study of electric and dielectric properties of thin-film organic materials that can be used as an active layer of photovoltaic cells. Primarily were studied the properties of the layers on the glass substrate, which consist of a thin active layer of mixture ZnPc/PCBM with Al or Au contact. On the selected samples were first measured current-voltage characteristics in the dark and during the exposure then on the selected samples were measured frequency dependences (impedance spectra) in the dark and finally on the selected samples were measured relaxation characteristics (transient response analysis – current dependences on time at constant voltage) in the dark. The measured data for transient measurement were evaluated using the methods of fractal analysis in HarFA. The results will be used to optimize the properties of photovoltaic cells.
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