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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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The synthesis of organic -conjugated systems for advanced photonic applications
Prekopová, Terézia ; Richtár, Jan (referee) ; Krajčovič, Jozef (advisor)
This diploma thesis is focused on the synthesis of new, organic, -conjugated systems with potential use in the field of singlet fission (SF). It is one of the most efficient multiexciton generation processes studied so far, which offers the potential to increase the efficiency of solar cells. The theoretical part focuses on the description of SF and the molecules providing this phenomenon. The first aim of the experimental part is focused on the synthesis of target pentacene and anthracene derivatives. The work presents and verifies three synthetic approaches to the preparation of these molecules, of which only one has proven to be successful. The second aim deals with the synthesis of intermediates that are crucial for the preparation of target pyrene fused pyrazaacenes. The synthesis consists of the oxidation of pyrene and the condensation of 4,5-diketone or 4,5,9,10-tetraketone with commercially available diamines or diamines prepared by us. A basic optical characterization was performed on these derivatives, which showed the effect of substitution on excimer emission. Assuming the same quantum fluorescence yield for all molecules and comparing the spectral measurements, it was found that the solid phase excimer emission is significantly higher than in solution.
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Growth of organic heterostructures on metal surfaces
Kugler, David ; Novák,, Jiří (referee) ; Procházka, Pavel (advisor)
Během depozice organických molekul na kovové substráty často dochází k spontánnímu uspořádání molekul vlivem mezimolekulárních a molekulárně-substrátových interakcí. Tento jev se nazývá samouspořádání a může být využit k vytváření atomárně přesných funkčních struktur. Vzrůstající zájem vzbuzují zejména tenké vrstvy organických polovodičů pro jejich potenciální využití v polovodičovém průmyslu. Efektivita takovýchto zařízení je však nevyhnutelně spojena s přechodovým odporem na rozhraní polovodiče a kovové elektrody. Studium typu růstu organických polovodičů na kovových substrátech je tak zcela zásadní pro jejich budoucí využití. Tato diplomová práce se nejprve zabývá vytvořením krycí monovrstvy substrátu Ag(111) z dobře uspořádaných molekul kyseliny 1,3,5-benzen-trikarboxylové (BTB). Hlavním cílem práce je pak použití této vrstvy jako substrátu pro růst dalších vrstvev tvořených molekulami pentacenu, což je jeden z intenzivně zkoumaných organických polovodičů. Bylo dosaženo pokrytí povrchu uspořádanou vrstvou pentacenu o rozloze vhodné pro praktické využití. Pro studium růstu molekulárních vrstev a jejich vlastností byla použita nízkoenergiová elektronová mikroskopie, skenovací tunelovací mikroskopie, rentgenová fotoelektronová spektroskopie a ultrafialová fotoelektronová spektroskopie.
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The synthesis of organic -conjugated systems for advanced photonic applications
Prekopová, Terézia ; Richtár, Jan (referee) ; Krajčovič, Jozef (advisor)
This diploma thesis is focused on the synthesis of new, organic, -conjugated systems with potential use in the field of singlet fission (SF). It is one of the most efficient multiexciton generation processes studied so far, which offers the potential to increase the efficiency of solar cells. The theoretical part focuses on the description of SF and the molecules providing this phenomenon. The first aim of the experimental part is focused on the synthesis of target pentacene and anthracene derivatives. The work presents and verifies three synthetic approaches to the preparation of these molecules, of which only one has proven to be successful. The second aim deals with the synthesis of intermediates that are crucial for the preparation of target pyrene fused pyrazaacenes. The synthesis consists of the oxidation of pyrene and the condensation of 4,5-diketone or 4,5,9,10-tetraketone with commercially available diamines or diamines prepared by us. A basic optical characterization was performed on these derivatives, which showed the effect of substitution on excimer emission. Assuming the same quantum fluorescence yield for all molecules and comparing the spectral measurements, it was found that the solid phase excimer emission is significantly higher than in solution.
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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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