National Repository of Grey Literature 45 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Synthesis and characterisation of advanced molecules with implemented adamantane skeleton
Jančík, Ján ; Maier,, Lukáš (referee) ; Krajčovič, Jozef (advisor)
This diploma thesis describes synthetic approach and characterization of advanced molecules with implemented adamantane skeleton and perspective use in attractive field of organic electronics. Three of four prepared molecules based on para-bis(2-thienyl)phenylene are original and totally new, and there were performed different synthetic approaches with comparison of yield, ecological and financial impact. Study of microwave synthetic approach was provided for cross-coupling reactions on para-bis(2-thienyl)phenylene skeleton. For all molecules were used ethyladamantyl and methyladamantyl substituents. Also, two completely new molecules based on 2,2':5',2''-terthiophene with ethyladamantyl and methyladamantyl substituents were prepared. In the next part were prepared new dimer structures of adamantane with possible application on field of polymers as bridge molecules. In the thesis were also made series of experiments for preparation of tetrasubstituted adamantane molecules, and for optimisation of preparation of spiroadamantane systems.
Preparation of organic electrochemical tranzistors for biosensorics
Ehlich, Jiří ; Vala, Martin (referee) ; Salyk, Ota (advisor)
The goal of this thesis is to describe the process used in preparation of organic electrochemical transistors thus biosensors for testing potential drugs aimed for cardiomyocytes. Then explore some physical properties of developed sensors such as adhesion of materials used, conductivity of developed structures and stability of developed structures in various water environments. As primary technology used for creating our OECTs was used inkjet printing of special inks with electrical properties on PET and PEN substrate cured with special treatment before and after printing. This thesis results in complete view on technology and development of biosensors we had created.
The synthesis and functionalization of diketopyrrolopyrrole derivatives for organic electronics
Mamleev, Kamil ; Halaksa, Roman (referee) ; Krajčovič, Jozef (advisor)
Nowadays, organic electronics is a promising field of science. Because of a number of advantages, materials based on organic substances can replace existing inorganic analogues in such devices as organic solar cells, OLED, OFET, biosensors, etc. In the theoretical part of the bachelor's thesis, the molecules of diketopyrrolopyrrole (DPP), dithioketopyrrolopyrrole (DTPP), and their derivatives were fully reviewed. An overview of the synthesis and the properties of the derivatives of these molecules was given. Possible applications of DPP and DTPP in various areas of organic electronics were provided. The experimental part of the bachelor's thesis described the synthesis of DTPP structures with thiophene and phenyl substituents. In addition, a modification of thiophene DTPP with S'S alkylation was demonstrated. All synthesized compounds were purified by silica gel column chromatography. The structures of the obtained products were characterized by 1H NMR spectroscopy.
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.
Microelectrode arrays for mioelectronic
Bráblíková, Aneta ; Vala, Martin (referee) ; Salyk, Ota (advisor)
Organic electronic biosensors are developed as suitable devices that can transform electrochemical processes within the cell membrane into an electronic signal and enable to measure electrical activity of excitable cells and tissues both in vitro and in vivo and thus represent valuable alternative to current cell monitoring methods. In this work we focus on the fabrication of electrophysiological sensors based on organic semiconductors printed by the material printing method. Microelectrode arrays (MEAs) are active components of the device, which can monitore cellular activity and above that stimulating cells with electrical pulses. The proposed platform should be used for cytotoxicity of potential drugs especially on cardiac cells (cardiomyocytes). The experimental part focus on specific production processes of platforms, which were prepared in the laboraty with emphasis on biocompatibility and conductivity of device.
IMPLEMETATION OF POLYCYCLIC SATURATED SYSTEMS IN ADVANCED SMART MOLECULES USABLE IN ORGANIC ELECTRONICS
Jančík, Ján ; Richtár, Jan (referee) ; Krajčovič, Jozef (advisor)
This essay deals with implementation of polycyclic saturated systems as bulky and very stable molecules, in advanced systems usable in organic electronics. It deals with theoretical aspects of structure and properties of polycyclic saturated systems, which based on available examples and literature are very perspective. Based on theoretical aspect in the first part of essay, the second part deals with synthesis of new molecule with incorporation of polycyclic saturated system usable in organic electronics. This part deals with all main intermediates synthetized via cross-coupling reactions.
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.
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.
Novel materials for organic and hybrid electronics and photonics
Kratochvíl, Matouš ; Yumusak,, Cigdem (referee) ; Táborský, Petr (referee) ; Weiter, Martin (advisor)
Obor organické elektroniky nabízí jedinečnou možnost masové výroby levné a ekologicky přívětivé elektroniky. Otevírá dveře novým funkcím a tvarům zařízení, které standardní elektronika na bázi kovu a křemíku neumožňuje Možnosti dané povahou organických látek a pokrok ve výzkumu syntézy nás zásobují novými materiály pro fotonické aplikace. Hlavní motivací této práce je hledání nových materiálů a zkoumání vztahu mezi jejich molekulární (a krystalickou) strukturou a vlastnostmi. Tato práce je zaměřena na studium optických a/nebo elektrických vlastností nových materiálů pro fotonické aplikace. Materiály prezentované v práci jsou organické i hybridní organicko-anorganické, u nichž je snaha získat to nejlepší z obou světů. Výzkum prezentovaný v této práci se skládá ze tří samostatných částí, které jsou propojeny cílem studovat vztah mezi strukturou materiálu a jeho vlastnostmi a metodami používanými ke studiu těchto vlastností. První část si klade za cíl představit materiály vykazující účinnou fluorescenci v pevné fázi (Solid-State Fluorescence, SSF). V této práci jsou prezentovány dvě série materiálů vykazujících SSF. Barva emise je řízena změnami skupin přitahujících elektrony v push-pull systémech molekul. Výsledky ukazují efektivní (>10%) emise pokrývající většinu viditelného spektra (~450–650 nm). Druhá část prezentovaného výzkumu zkoumá vliv thionace na známou skupinu nízkomolekulárních polovodičů – diketopyrrolopyrrolů (DPP). Prezentované výsledky ukazují ve studovaných molekulách výraznou preferenci n-typové chování následkem thionace, s řádovým zvýšením pohyblivosti elektronů, a také působivě nízko ležící hladiny LUMO (~ 4,5 eV). Třetí část uvedených výsledků je zaměřena na perovskitové materiály pro fotonické aplikace. Hybridní materiál – organo-olovnato-halogenidový perovskit je již téměř půldruhého desetiletí v centru pozornosti výzkumníků v oblasti pokročilé fotoniky. Perovskitové solární články prokazují pozoruhodnou účinnost, avšak jejich využití stále brání problémy se stabilitou. V této práci je prezentována studie stability jako referenční bod pro další výzkum v této oblasti a pro získání vhledu do procesů ovlivňujících stabilitu perovskitových materiálů a solárních článků. Následně je navržen a otestován přístup ke zvýšení stability a výkonu článků, využívající materiály studované ve druhé studii.
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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