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Book of Abstracts and Programme. Polymers and Organic Materials for Electronics and Photonics: Science for Applications. Prague Meeting on Macromolecules /81./
Pfleger, Jiří ; Cimrová, Věra
The book of abstracts contains the summary of 8 plenary and 24 invited lectures, accompanied by 38 oral contributions and 88 posters presented at the conference. The main areas covered were the design, synthesis, processing and characterization of novel functional organic materials and polymers, electrical, photoelectrical, optical and nonlinear optical phenomena, organic and hybrid electronic and photonic devices, and advanced materials and composites for biosensors, bioelectronics, and biophotonics. Particular session was dedicated to applications in flexible and wearable organic electronics and smart packaging. Due to big expectations in the application field of large area printed electronics, wearable devices, printed RFIDs, displays, solar cells and sensors there is a growing demand to prepare polymers with better defined morphology and chemical and structural stability. Hence, improvement in the molecular design and new synthetic and processing routes is strongly required. A special emphasis was given to attract the scientists from the application field of printed electronics to provide a necessary feedback for further development of new materials with desired properties.
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Preparation of Partially Fluorinated Polyaromatics by Photocyclization of Stilbenes.
Jakubík, Pavel ; Storch, Jan ; Žádný, Jaroslav ; Pfleger, Jiří ; Církva, Vladimír
Synthetic strategies to partially fluorinated polyaromatics by photocyclization were examined, leading to both 1,2,3,4-tetrafluoro[6]helicene (1) and 1,2,3,4,13,14,15,16-octafluoro[6]helicene (2), and to 1,2,3,4-tetrafluoro[5]phenacene (3) and 1,2,3,4-tetrafluoro[6]phenacene (4). Thin films of the prepared compounds were characterized for their electrical properties and incorporated into OFET structures.
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Study of electrical and dielectric properties of conducting polymers
Varga, Martin ; Prokeš, Jan (advisor) ; Petzelt, Jan (referee) ; Pfleger, Jiří (referee)
Title: Study of electrical and dielectric properties of conducting polymers Author: Mgr. Martin Varga Department: Department of Macromolecular Physics Supervisor: RNDr. Jan Prokeš, CSc., Department of Macromolecular Physics Abstract: Charge transport in polyaniline (PANI) and polypyrrole (PPy) was studied in respect to various oxidants, dopants, morphology, and other modifica- tions in their synthesis. The mechanism of transport was discussed in the frame- work of combination of several models characteristic for disordered solids due to inherent heterogeneous structure of conducting polymers. Effect of drying on conductivity was studied and the long-time limit was explained with the diffusion- based model for bulk materials. For PPy nanotubes stability in strong alkaline media and aging were studied by AC and DC techniques. While conductivity of naturally aged samples after two years remained in the same order of magni- tude, after exposure to alkaline media or accelerated aging at high temperatures, conductivity decreased several orders of magnitude. Degraded material exhibited strong disorder and the transport model was completely changed. Despite severe treatment electrical properties were still comparable to other as-prepared mate- rials. Finally, an application example as ammonia sensor, the response of...
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Study of electric and photoelectric effects in organic semiconductors
Chomutová, Radka ; Toušek, Jiří (advisor) ; Pfleger, Jiří (referee)
This work studies various electrical properties of polymer layers of polyaniline, polythiophenes and poly(((benzothiadiazol)4,7-di(thien-2-yl)-5,6-difluoro-2,1,3-benzothiadiazol). Goal of this work is to determine electrical and photoelectrical properties as are electric conductivity, mobility of the free charge carriers, work function of the electrons and diffusion length of excitons. Conductivity was obtained through current and voltage contacts, mobility was measured by CELIV method (charge extraction by linearly increasing voltage). To determine work function a Kelvin probe was built and utilized. Diffusion length of excitons was determined from photovoltage spectrum formed by illuminating space charge region of the polymer.Space charge region on surface of the polymer can arise spontaneously or by laying suitable contact electrode. Powered by TCPDF (www.tcpdf.org)
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Studium transportních vlastností některých polymerních vrstev
Růžička, Aleš ; Toušková, Jana (advisor) ; Pfleger, Jiří (referee)
This work studies various properties of polymer layers and hybrid layers containing inorganic nanoparticles. MEH-PPV and Polythiophene films are characterized by different experimental techniques. Dark J-V characteristics were measured at different temperatures and the mobility of holes was evaluated in a few cases. Photovoltage spectra are used for a determination of the exciton diffusion length and the SPV method is discussed. The influence of the inorganic nanoparticles CdS and ZnO incorporated into the polymer layers is studied by various experimental methods and the applications of these layers in the inorganic-organic hybrid solar cells are discussed. The inorganic nanoparticle size distributions are obtained by several experimental techniques and the results correspond with the assumptions.
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Photogeneration of charge carriers in substituted polyacetylenes
Jex, Michal ; Pfleger, Jiří (advisor) ; Nachtigall, Petr (referee)
We present an improved model of charge carrier photogeneration in π-conju- gated polymers with weak intermolecular interactions based on the model of Arkhipov. It includes quantum effects affecting the creation of charge transfer states, which occurs as an intermediate step in the free charge carrier photo- generation process. The electrostatic potential between the electron and the hole and transfer integrals needed for the calculation of the potential barrier for the charge transfer state dissociation are calculated quantum-chemically. We apply our model on experimental data of the charge carrier photogenera- tion efficiency in poly[1-trimethylsilylphenyl,2-phenyl]acetylene to explain its dependence on applied electric field. We eliminate several problems of the previous model. We are able to fit experimental data with just one set of parameters in the whole interval of the applied electric field. We do not have to consider several intervals of the electric field separately as in the previous work and reduce the number of needed parameters to three. Key words π-conjugated polymers, charge carrier photogeneration, photoconductivity 1
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Development and optimization of systems for SERS on single molecule level
Michlová, Magdalena ; Vlčková, Blanka (advisor) ; Pfleger, Jiří (referee) ; Procházka, Marek (referee)
AABBSSTTRRAACCTT Dimers and small aggregates as well as compact aggregates of Ag nanoparticles (NPs) were assembled and chemically anchored to supporting surfaces. The supporting surfaces were either glass slides or SiO2 - coated Cu or Au grids for TEM, both chemically functionalized by 3-aminopropyltrimethoxysilane (APTMS). Compact aggregates of Ag NPs incorporating protoporphyrin IX (PPIX) molecules were prepared by adsorption of chlorides in the presence of PPIX. Dimers and small aggregates of Ag NPs were assembled by selected molecular linkers: 4,4'-diaminoazobenzene (DAAB), 4,4'-diaminoterphenyl (DATP) and 5,10,15,20-tetrakis(4-aminophenyl)porphine (TAPP). The most efficient strategy of dimers and small aggregates preparation has been their assembling by a three - step procedure involving (i) attachment of isolated Ag NPs to the NH2 groups of APTMS functionalized TEM grid, (ii) attachment of molecular linker (with two functional NH2 groups in para position) to Ag NPs by a one terminal NH2 group, and (iii) attachment of Ag NPs to the second, free terminal NH2 group of the linker. In this procedure, the control over the perpendicular orientation of the bifunctional linker and its attachment by one terminal group to Ag NP surface has been accomplished by functionalization of Ag NPs by adsorbed citrate...
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Preparation and properties of α,ω-bis(terpyridyl)oligothiophenes and related supramolecular polymers
Štenclová, Pavla ; Svoboda, Jan (advisor) ; Pfleger, Jiří (referee)
Presented diploma thesis describes synthesis of novel α,ω-bis(terpyridyl)bithiophenes and α,ω-bis(terpyridyl)terthiophenes with alkyl substituents on thiophene rings. The α,ω- -bis(terpyridyl)oligothiophenes were prepared using Suzuki-Miyaura coupling of 4'-(5- -bromo-3-alkylthien-2-yl)terpyridine with 2,5-thiophenediboronic acid and 2,2'-bi(1,3,2- -dioxaborolane), respectively. The succesfull transformation of 4'-(5-bromo-3-alkylthien-2- -yl)terpyridine to corresponding bis(terpyridyl)oligothiophenes was confirmed by NMR and HR-MS analyses and IR spectroscopy. UV-vis spectroscopy, excitation and emission photoluminescence (suplemented with determination of photoluminescence quantum yields) and cyclic voltammetry were used to study spectroscopic and redox properties of novel α,ω-bis(terpyridyl)oligothiophenes and previously prepared unsubstitued α,ω-bis(terpyridyl)bithiophene and α,ω-bis(terpyridyl)- terthiophene. Interaction of zinc ions with ligands soluble in tetrahydrofurane was studied using UV-vis spectroscopy and emission photoluminescence spectroscopy. Main-chain supramolecular polymers were sucessfully prepared from four soluble ligands and zinc ions. Properties of prepared polymers were studied using UV-vis spectroscopy, excitation and emission photoluminescence spectroscopy and IR...
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