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The synthesis and study of new derivatives of diketopyrrolopyrroles for organic electronics
Cigánek, Martin ; Maier, Lukáš (referee) ; Krajčovič, Jozef (advisor)
This diploma thesis describes organic pigments of diketopyrrolopyrroles (DDPs) possessing properties applicable in attractive and perspective areas of organic electronics and photonics. The modification of the DPP skeleton was performed by nucleophilic substitution by various alkyl chains and 5 series of DPP derivatives were prepared. The regioselectivity of N-alkylation and also the photophysical properties of the prepared derivatives were studied. A key product of this work is the N,N'-ethyladamantyl derivative of DPP, which exhibited ambipolar characteristic with excellent electron mobility of 0.2 cm2 V–1 s–1. Further, the -conjugation of the above-mentioned DPP derivative was extended by 1 and 2 thiophene units at positions 3,6 and the effect of this modification on optical properties of the resulting derivatives was investigated. A new modified N,N'-unsubstituted DPP derivative was also prepared. The last point of this thesis was the study of the incorporation of formyl functional groups into the skeleton of key N,N'-ethyladamantyl DPP derivative.
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Testing of hydrogen sensor based on organic materials
Petrová, Lenka ; Hubálek, Jaromír (referee) ; Boušek, Jaroslav (advisor)
Práce je zaměřena na problematiku bezpečnostních vodíkových senzorů. Základní principy a teorie vodíkových senzorů je rozebrána v první části práce. Je navržena metodologie testování organických vodíkových senzorů vyvinutých a vyrobených na Fakultě Chemické Vysokého Učení Technického v Brně. Nejslibnější organický material byl testován. V závěrečné části byl navržen teplotní regulátor pro použití s keramickou senzorovou platformou.
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Novel diketopyrrolopyrroles for organic photovoltaics
Hrabal, Michal ; Zmeškal, Oldřich (referee) ; Vala, Martin (advisor)
The aim of this diploma thesis is to conduct optical and photovoltaic characterization of derivatives of diketopyrrolopyrrole (DPP) as materials suitable for fabrication of bulk heterojunction organic solar cells. The charge transfer from donor material (DPP) to acceptor material (PCBM) is studied by a quenching of fluorescence. The photovoltaic response is studied by current – voltage characteristic which can tell us crucial parameters such as shor circuit current density Jsc, open circuit voltage Voc, fill factor FF and power conversion efficiency PCE. Optical characterization was carried out for symmetrical DPP derivatives (U69 and U97) which both contained diphenylaminstilbene moiety and differed in N-alkyl group. On the other hand photovoltaic characterization was conducted for analogous but asymmetrical materials (U70 and U99). Material U29 was characterized as well but its properties proved to be very poor. Both these characterizations tell us that materials with shorter solubilization groups (U69 and U99) are more suitable candidates. Achieved PCE for U70 was 0,74 % and for U99 up to 1,39 %. From these values one can say that small molecule organic materials can be used for fabrication of solar cells.
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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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Electrical transport properties of molecular materials for smart applications
Ivancová, Anna ; Vala, Martin (referee) ; Přikryl, Radek (advisor)
This master´s thesis deals with possibilities of application of new organic molecular materials for electronic devices. Nowadays it is a very attractive field of research, because of the tendencies in industry to miniaturize, reduce production costs and develop new, eco-friendlier, processes of production. The theoretical part of the thesis provides a short overview of organic materials suitable for smart applications and thin films issues including their characterization. The experimental part is dedicated to means how to prepare thin-film electronic components to silicon wafers for thin films field effect transistors. The obtained results in the last part of thesis are discussed about properties of prepared thin films, in the concrete about the electrical transport properties, in the connection with the condition of preparation.
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Synthesis and studies of novel difuranone heterocycles for optoelectronic applications
Szotkowski, Martin ; Ing. Jan Vyňuchal, Ph.D (referee) ; Krajčovič, Jozef (advisor)
Organic electronics is a progressive field of science that combines knowledge of many disciplines concerned with the study and application possibilities of organic molecules from both, the low-molecular segment as well as the oligomers and polymers. Such molecules are well recognizable by their excellent properties and variability of their structure. This thesis deals with properties, applications and brief research review of benzodifuranones and diketopyrrolopyrroles as the representatives of smart molecules. Furthermore various synthetic approaches to the preparation of both symmetrical and unsymmetrical benzodifuranones are described. Experimental part is focused on the development of hydroxy(thiophene-2-yl) acetic acid initial intermediate for the development of benzodifuranone analogues containing aromatic thiophene core.
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Preparation and study of the reactivity of a new series of N, N'-substituted diketopyrrolopyrrole (DPP) for organic photonics
Cigánek, Martin ; Vyňuchal, Jan (referee) ; Krajčovič, Jozef (advisor)
Currently, the major trend is the development of materials that could be used for transformation of solar energy into electrical energy. Organic photovoltaics studies this area of interest and especially in recent years increasingly tries to put functional materials of organic origin into practice. These materials belong to a group of "high performance pigments" due to their exceptional and relatively stable properties. One of the most important molecules are the diketopyrrolopyrroles (DPP) derivatives. The theoretical part of this bachelor work describes the organic electronics and photonics, DPP derivatives, various synthetic routes of DPP, properties of particular DPP derivatives and the dependence of their properties on the used substituents. There are described separation and analytical methods most commonly used in organic synthesis too. The experimental part describes the preparation of the backbone DPP containing thiophene units. The following are the modifications of DPP backbones with N,N‘-alkylation and N,N‘-arylation.
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Study of sensoric properties of organic semiconductors
Saska, Pavel ; Šedina, Martin (referee) ; Salyk, Ota (advisor)
Compounds based on diketopyrrolopyrrole are organic pigments that behave as semi-conductors. Their analogues with pyridyl side group are due to their sensitivity to hydrogen potentially useful as hydrogen sensors. The aim of this work was to examine properties of sensors with an active layer of diketopyrollopyrolle derivatives. The sensors were tested on an apparatus built for this purpose at FCH VUT in Brno. More specifically, changes to conductivity of these sensors in the presence of hydrogen under various conditions were studied.
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Organic materials for photovoltaic conversion of solar energy
Vrchotová, Jana ; Vala, Martin (referee) ; Weiter, Martin (advisor)
This bachelor´s thesis deals with new perspective organic molecular materials for use in photovoltaic energy conversion. A theoretical part of this project contains brief introduction to photovoltaics and search themed on organic photovoltaics. The aim of the experimental part was preparation of thin layers of diketopyrrolopyrrole and hemiisoxindigo derivatives and study of optical properties of solutions and thin layers prepared from these materials.
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