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Utilization of nanomaterials for organic electronic and photovoltaics
Flimel, Karol ; Žídek, Jan (referee) ; Weiter, Martin (advisor)
The study of the new materials potentially usable for organic photovoltaic and electronics are getting very important from the point of ecological and financial view. Organic electronic devices are getting more and more popular and it is only up to us to search for the new ones that are able to improve their physical properties. The aim of this thesis is to search for materials like have been mentioned above which have very good semiconducting properties. Solutions of pure materials and its mixtures with different concentrations of fullerene have been investigated by ultra-violet spectroscopy, classical fluorescence and time resolved spectrometry. Mainly, were studied the influence of the central atom and side substituents for the optical and electronical properties of our materials of interest. With adding fullerene was observed quenching phenomena of the fluorescence, because all these new materials show usually high photoluminescence. Based on the given results, the most suitable materials had been chosen to provide trial of making organic solar cell, and therefore investigated by the mean of electric measurements (direct current).
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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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Utilization of nanomaterials for organic electronic and photovoltaics
Flimel, Karol ; Žídek, Jan (referee) ; Weiter, Martin (advisor)
The study of the new materials potentially usable for organic photovoltaic and electronics are getting very important from the point of ecological and financial view. Organic electronic devices are getting more and more popular and it is only up to us to search for the new ones that are able to improve their physical properties. The aim of this thesis is to search for materials like have been mentioned above which have very good semiconducting properties. Solutions of pure materials and its mixtures with different concentrations of fullerene have been investigated by ultra-violet spectroscopy, classical fluorescence and time resolved spectrometry. Mainly, were studied the influence of the central atom and side substituents for the optical and electronical properties of our materials of interest. With adding fullerene was observed quenching phenomena of the fluorescence, because all these new materials show usually high photoluminescence. Based on the given results, the most suitable materials had been chosen to provide trial of making organic solar cell, and therefore investigated by the mean of electric measurements (direct current).
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RESPONSE OF SURFACE MORPHOLOGY IN COBALT-FULLERENE MIXTURE FILMS UPON VARIATION OF THE METAL CONTENT
Lavrentiev, Vasyl ; Lavrentieva, Inna ; Vacík, Jiří
The morphology and roughness of the films show great change around some critical composition x(c) of the mixture film (x(c) approximate to 3). The films with lower Co content (x < 3) is rather smooth and the roughness is rather low. However, if x >= 3, the roughness of the CoxC60 films dramatically increases and sharp protrusions appear on the surface that reflects an important phase transformation in the film structure. The obtained AFM results define the concentration interval of the Co solubility in solid C-60 (x < 3), which was found to be narrower than that evaluated from spectroscopic experiments (see the text). This interval suggests a formation of the Co1C60 and Co2C60 fullerides in the CoxC60 mixtures where the Co atoms occupy the tetrahedral holes in the fullerene lattice. The dramatic change of the surface morphology at x >= 3 reflects the pronounced Co clustering which likely occurs due to numerical filling the octahedral pores. Formation of the protrusions on the surface of the supersaturated CoxC60 mixture films (x > 3) is a consequence of the compressive stress arising in the film due to the Co clustering.
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Electroanalysis with phthalocyanine modified HOPG electrodes
Mansfeldová, Věra ; Janda, Pavel
In this papers we presented modification of highly oriented pyrolitic graphite (HOPG) by two different phthalocyanine (Pc) derivatives and two different deposition techniques. We have investigated electrode modified by fullerene-derived phthalocyanine and cobalt tetraneopentoxyphthalocyanine (CoTNPc) to consider how different modification procedure-electrodeposition and drop evaporation and composition of phthalocyanine influences detection of model compound, L-cysteine.
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