Dissertations / Theses on the topic 'Molecular organic conductors'
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ASHOKA, SAHADEVAN SUCHITHRA. "Anilate-based Molecular Building Blocks for Metal-Organic Frameworks and Molecular Conductors." Doctoral thesis, Università degli Studi di Cagliari, 2019. http://hdl.handle.net/11584/260592.
Full textTaniguchi, Masateru. "Studies on Structures and Physical Properties of Organic Molecular Conductors." Kyoto University, 2001. http://hdl.handle.net/2433/150659.
Full textBranton, Philip Michael. "Molecular design of inorganic materials." Thesis, University of Surrey, 1998. http://epubs.surrey.ac.uk/844618/.
Full textAshoka, Sahadevan Suchithra. "Anilate-based molecular building blocks for metal-organic frameworks and molecular conductors Conducting Anilate-Based Mixed-Valence Fe(II)Fe(III) Coordination Polymer: Small-Polaron Hopping Model for Oxalate-Type Fe(II)Fe(III) 2D Networks Nanosheets of Two-Dimensional Neutral Coordination Polymers Based on Near-Infrared-Emitting Lanthanides and a Chlorocyananilate Ligand." Thesis, Angers, 2019. http://bu.univ-angers.fr/Contact.
Full textThis work reports on the design, synthesis and characterization of novel anilate-based functional molecular materials showing luminescent, magnetic and/or conducting properties. The family of anilate ligands comprises several derivatives obtained by introducing various substituents (H, F, Cl, Br, I, CN, etc.) at the 3 and 6 positions of the common 2,5-dihydroxy-1,4-benzoquinone framework. Among the anilate ligands, the only known heterosubstituted anilate with Cl/CN substituents at the 3,6 positions, ClCNAn2-, have been selected for preparing a novel family of 2D layered coordination polymers (2D CP) with both 3d metal ions and 4f lanthanide ions, through a general and straightforward synthetic strategy. i) Mixed-valence FeIIFeIII 2D CP, formulated as [TAG][FeIIFeIII(ClCNAn)3], containing, the tris(amino)-guanidinium (TAG) cation for the first time in such 2D networks has been synthesized and thoroughly characterized. ii) 2D CPs based on NIR-emitting lanthanides (YbIII, NdIII, ErIII) and the ClCNAn2- ligand, have been prepared and characterized. These layered compounds were exfoliated to nanosheets, by sonication-assisted solution synthesis. Time-resolved photoluminescence studies performed on both the bulk and nanosheets are also highlighted. iii) Novel family of heteroleptic 2D CPs based on NIR-emitting lanthanides and mixed ligands (ClCNAn2- and carboxylate ligands (DOBDC and F4-BDC)), were prepared and characterized. vi) Novel family of 2D CPs based on DyIII and ClCNAn2- were prepared in order to investigate their magnetic properties. v) Furthermore, the ability of anilate ligands to work as components of BEDT-TTF- based molecular conductors have been demonstrated through the synthesis, via electrocrystallization technique. vi) П-d hybrid multifunctional paramagnetic molecular conductors BEDT-TTF and [Fe(ClCNAn)3]3-) were also studied
Allain, Magali. "Études structurales par diffraction des rayons X appliquées à des cages supramoléculaires et à des conducteurs moléculaires." Electronic Thesis or Diss., Rennes 1, 2022. http://www.theses.fr/2022REN1S081.
Full textThe discrete self-assembled metal assisted structures are big size edifices which do not crystallize easily and decompose rapidly. Moreover, the resolution of these structures is difficult because of the medium quality of the diffraction data sets. Different crystals selection techniques and a refinement method, applied to the supramolecular cages, are discussed, with a particular focus on the use of the Squeeze program which allows the suppression of the disordered atoms and molecules contributions. Two types of isolated and interlocked cages are structurally described. In the second part, a series of new organic conducting materials based on TMTSF and on TTF derivatives, incorporating a novel fluoro-tantalate anion, is described. The structure-conducting properties relationship is discussed. The first Bechgaard phase with a magnetic anion, namely hexafluororhenate, is described, together with its temperature dependent stability and conducting properties. TMTSF and BEDT-TTF have been associated to several mixed tantalum, rhenium or phosphorous hexafluoro anions to provide new conducting alloys. These syntheses also afforded crystalline materials with original anions. Two methods to estimate the oxydation state of the TMTSF donors are compared for several radical cation salts, either prepared during this PhD work or selected from a crystallographic data base
Dhakal, Pashupati. "Angular Magnetoresistance Oscillations in the Molecular Organic Conductor (DMET)2I3: Experiment and Calculation." Thesis, Boston College, 2010. http://hdl.handle.net/2345/1566.
Full textQuasi-one dimensional (Q1D) molecular organic conductors are among the most exciting materials in condensed matter physics, exhibiting nearly every known ground state. They are highly anisotropic, structurally and electronically, and show large oscillatory phenomena in conductivity for magnetic field rotated in different crystalline planes. Several theoretical works have been published to explain these angular magnetoresistance oscillation (AMRO) effects, but the underlying physics remains illunderstood. Here, we present measurements and calculations of magnetotransport in the molecular organic (super)conductor (DMET)2I3 which detect and simulate all known AMRO phenomena for Q1D systems. Employing, for the first time, the true triclinic crystal structure in the calculations, these results address the mystery of the putative vanishing of the primary AMRO phenomenon, the Lebed magic angle effect, for orientations in which it is expected to be strongest. They also show a common origin for Lebed and so-called "Lee-Naughton" oscillations, and confirm the generalized nature of AMRO in Q1D systems. Furthermore, we report the temperature dependence of the upper critical magnetic field in (DMET)2I3, for magnetic field applied along the intrachain, interchain, and interplane directions. The upper critical field exhibits orbital saturation at low temperature for field in all directions, implying that superconductivity in (DMET)2I3 is conventional spin singlet
Thesis (PhD) — Boston College, 2010
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Physics
Galbiati, Marta. "Molecular Spintronics : from Organic Semiconductors to Self-Assembled Monolayers." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112158/document.
Full textThis thesis targets the field of molecular spintronics and more particularly the new spin polarization tailoring opportunities, unachievable with inorganic materials, which arise from the ferromagnetic metal/molecule hybridization at the interface.: the new concept of Spinterface.In a first part we investigate Self-Assembled Monolayers (SAMs) based magnetic tunnel nanojunctions. This system appears to be a highly promising candidate to engineer the properties of spintronics devices at the molecular level since SAMs are the equivalent of a molecular LEGO building unit. We present the functionalization of the half-metallic manganite (La,Sr)MnO3 (LSMO) with alkyl phosphonic acids SAMs and the fabrication of LSMO/SAMs/Co magnetic tunnel nanojunctions with an area of few 10 nm2. MR of 30% to 50% is observed in most of the devices, while we report even up to 250% tunnel magnetoresistance (TMR) at low temperature. The most striking point is the robustness of the signal with bias voltage with still 20% TMR observed in the volt range. The influence of the molecular chain length is also investigated and represents a first step towards achieving molecular tailoring.In a second part we develop organic spintronics devices relying on high Curie temperature metallic ferromagnetic electrodes and standard organic semiconductor such as Co/Alq3/Co organic spin valves (OSVs). Junctions have a large area (section of 50 or 100 µm) and are fabricated in-situ by shadow mask. Magnetoresistance (MR) effects at room temperature are investigated with -4% MR observed in Co/Alq3/Co OSVs and +8% MR in Co/MgO/Alq3/Co OSVs. The role of the two interfaces on the spin polarization properties of the devices is also investigated. A stronger spin-dependent hybridization is found to occur at the bottom Co/Alq3 interface inverting the spin polarization on the first molecular layer. The observation of spin polarization inversion at room temperature demonstrates that spinterface effects can strive up to room temperature
Lattach, Youssef. "Development and characterization of sensing layers based on molecularly imprinted conducting polymers for the electrochemical and gravimetrical detection of small organic molecules." Phd thesis, Conservatoire national des arts et metiers - CNAM, 2011. http://tel.archives-ouvertes.fr/tel-00699628.
Full textDahlstedt, Emma. "Synthesis of Electroactive Molecules Based on Benzodioxins and Tetrathiafulvalenes." Doctoral thesis, KTH, Chemistry, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3601.
Full textThis thesis deals with the synthesis of electroactiveorganic compounds. The synthesis of ethylenedioxy-benzodioxinstri-dioxin and tetra-dioxin are described. These molecules wereprepared with the aim of creating donor molecules for cationicradical salts. The symmetric analogs of tri-dioxin,methylenedioxy-derivative and ethylenedioxy-naphthalene werealso synthesized. Three different cation radical salts with 2:1stoichiometries were obtained from tri-dioxin, whiletetra-dioxin merely provided polycrystalline materials.Tri-dioxin and tetra-dioxin were also successful as operationalmatrixes in PALDI-TOF.
Tetrathiafulvalenes with the2-dialkyl-amino-1,3-dithiolium-4-thiolate mesoion asbuilding-block was also synthesized. A series of doublyalkylthiol-substituted TTFs were prepared with the aim offorming self-assembly monolayers on gold surfaces in theapplication of organic thin film field-effect transistors.Film-formation for two TTFs were studied and they providedrelatively dense packed monolayers with a discrete distance ofthe TTF moiety from the gold surface.
The mesoionic compound was also for the first time used inanumpolungreaction. The electrophile obtained in situ bytreatment of mesoion with sulfuryl chloride was reacted with avariety of electron-rich aromatic compounds. From the receivedproducts three new arylthio-substituted TTFs weresynthesized.
Keywords:Synthesis, Benzodioxin, Tetrathiafulvalene,Mesoion, Organic Conductor, Cation Radical Salt, CyclicVoltammetry, Electrocrystallization, Self-Assembly Monolayer,SAM, Organic Field-Effect Transistor, OFET
Magri, Andrea. "Multifunctional complexes for molecular devices." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAE036/document.
Full textAluminum-based organic semiconductors (OSCs) were systematically synthesized and studied by photophysical and electrochemical methods to identify a relationship between their chemical structure and electronic properties, using Alq3 as benchmark. Experimental HOMO and LUMO were compared to those computed. In addition, newly developed methods were implemented to generate morphologies and calculate charge carrier mobilities. The hole mobility of Al(Op)3 was measured in thin film transistors: 0.6-2.1×10−6 cm2V−1s−1. By photoemission spectroscopy techniques, the Co/Al(Op)3 hybrid interface was probed. Two hybrid interface states (HISs) were unraveled; the SP (spin polarization) of HIS1 is 8% higher than bare cobalt, whereas the SP of HIS2 is 4% lowered. At last, phenalenyl-based dysprosium SMMs (single-molecule magnet) were investigated. [Dy(Op)2Cl(HOp)(EtOH)] showed an energy gap of 43.8K and a quantum relaxation time of 5x10-4s
Bulut, Ibrahim. "Synthèse et caractérisation de matériaux semi-conducteurs pour la conversion photovoltaïque." Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAE005/document.
Full textThe aim of this thesis is to develop efficient semi-conducting organic materials for organic photovoltaics. This work is focuses on the optimization of electron-donor organic semiconductors for the preparation of bulk heterojunction devices, in blend with a fullerene derivative used as electron-acceptor material. More specifically, it is to perform a systematic optimization study of two reference families (macromolecular and molecular respectively) from the laboratory, which have already led to interesting photovoltaic performances. For this, we followed a structured and systematic approach targeting the most relevant chemical parameters to be varied. To determine the properties of new materials synthesized, spectroscopic, electrochemical, structural, charge transport and photovoltaic characterizations were systematically made
Xiao, Yiming. "Engineering, Synthesis and Characterization of New - π Conjugated (Macro)molecular Architectures for Organic Optoelectronics : application toward ambipolar materials." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066638/document.
Full textIn the general field of organic electronics, including Organic Photovoltaic (OPV), Organic Light-Emitting Diode (OLED) and Organic Field-Effect Transistor (OFET), the interest for the ambipolar organic materials have increased remarkably during the recent years.In this context, we were interested, in this present work, in designing and preparing different new self-organized semiconducting architectures in which it could be possible to inject and transport both holes and electrons. Our approach is based on liquid crystalline (LC) materials incorporating different kinds of electron-donor (p-type) and electron acceptor (n-type) π-conjugated systems in a unique molecular or macromolecular architecture. Thus, we synthesized and characterized different series of organic semiconductors such as donor-σ-acceptor discotic LC dyads and triads, donor-σ-acceptor calamitic LC dyads, and donor-σ-acceptor side-chain LC polymers bearing discotic side-groups. Their thermal behaviors, optical and electronic properties, self-organization properties both in bulk and in thin films, and finally charge transport properties are presented and discussed.Based on different characterization techniques, we demonstrated that all these series of materials present liquid crystalline properties in self-organizing in different structure such as columnar, lamellar, and lamella-columnar organizations. More particularly, these materials exhibit spontaneous nanosegregation of p-type and n-type entities in bulk, leading to well defined distinct conductive channels for each type of charge carriers as evidenced by the preliminary ambipolar charge transport properties observed by Time-of-flight and Field effect transistor measurements
Destouesse, Élodie. "Vers l'industrialisation de cellules solaires photovoltaïques organiques imprimables à base de semi-conducteurs moléculaires." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0085/document.
Full textOrganic solar cells are often called “polymer” solar cells. This term comes from the fact that the active layer of such solar cells have been widely made with a donor polymer. The use of polymer inthe active layer gives interesting filming properties that can be used to produce these solar cells industrially with a high speed printing process. Yet, another type of donor materials exists: the small molecules. Deposited by thermal evaporation, this type of materials can allow to reach high efficiency solar cells. Because of their poor filming properties, small molecules were not a good candidate for an industrialization using high speed printing. However, in 2012 several solution processable small molecules were proven particularly promising by demonstrating high efficiency at a laboratory scale.These encouraging results let imagine that it could be possible to produce organic solar cells with such materials. This PhD work has been done in collaboration with ARMOR, a company highly implied in the commercialization of organic solar cells, in order to evaluate if small molecules materials could be use dindustrially with a high speed printing process. The p-DTS(FBTTh2)2 has been chosen for this study. It has been shown that it is possible to reach efficiencies as high as 2 % with such a material, using non toxicsolvents and by making the solar cell in the air with a Doctor Blade. Nevertheless, the industrialization ofthe p-DTS(FBTTh2)2 has not been pursued due to the rapid degradation of this molecule in the air. This work presents a method that can be used to evaluate the industrialization of other efficient small molecules
Aboubakr, Hecham. "Synthèse et caractérisation de semi-conducteurs organiques pour des applications optoelectroniques et capteurs." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4070.
Full textThe work reported herein concerns the synthesis and the characterization of new organic semiconductors built around the bithiophene core. It was relied on an extended work carried out previously in our laboratory on distyryloligothiophene derivatives. The main part of this work was dedicated to develop new functionalized organic semi-conductors with the aim to improve their properties for optoelectronic applications, mainly for: i) the realization of transistors with organic thin layer (OFETs), ii) the elaboration of solar cells from push-pull derivatives and iii) the development of sensors. The first chapter is devoted to the functionalization of the benzo-[2,1-b:3,4-b ']bithiophene-4,5-dione core either by mesogenic or aminostyryl groups with the purpose to improve, using liquid crystal properties, the microscopic ordering and the electrical performances of the synthetized organic semiconductors as well as their solution processability. Besides the liquid crystal properties characterization showing interesting behavior, the OFET devices have been made from those semiconductors but unfortunately have led to, as unexpected, poor charge transport properties. Some structural modifications have been done in order to optimize the charge transport characteristics nevertheless their electrical characterization still under progress up to now. In a second part, some push-pull derivatives, having a cruciform-like structure, have been synthetized and characterized in order to use them as an active organic layer in photovoltaic devices. Their optoelectronic properties have been evaluated and reported
Lucas, Fabien. "Systèmes π-conjugués pour l'électronique organique : composés donneur-spiro-accepteur et anneaux moléculaires." Thesis, Rennes 1, 2020. http://www.theses.fr/2020REN1S042.
Full textOrganic electronics is a field of research dealing with the development of new technologies based on organic semiconductor materials (OSCs). In general, two approaches are used for the molecular design of OSCs. The first approach consists in assembling efficient molecular fragments, in order to synthesize functional materials for a specific application such as phosphorescent organic light-emitting diodes (PhOLEDs). The second approach is more risky as it aims to develop new molecular fragments which may have one or several desired properties for a given application. In this thesis work, both approaches have been developed. On the one hand, we have developed host materials for PhOLEDs by adjusting their properties (first approach), and, on the other hand, we have been interested in a new generation of OSCs: molecular nanorings (second approach). In a first part, within the framework of developing new host matrices for simplified PhOLEDs so called single-layer, we will present a study of two families of SCOs based on a Donor-spiro-A-acceptor molecular design. This work has enabled to reach the, green and blue PhOLEDs displaying the highest overall performances ever reported in literature. In a second part, after a detailed bibliographical study on the synthesis and on the singular properties of nanorings, we will present our investigations in the field of nanorings. We report herein the synthesis and the study of two families of molecular nanorings constructed with carbazole units. This work allowed us to incorporate for the first time molecular nanorings in organic field-effect transistors in order to study their transport properties
Bechu, Damien. "Polymères de coordination cristallins conducteurs à base de dérivés du tétrathiafulvalène." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAF018.
Full textPorous coordination polymers or Metal-Organic Frameworks (MOFs) are crystalline architectures displaying interesting properties such as gas storage, gas separation and catalysis. Investigations described in this PhD dissertation focused on a property less explored for these materials, using coordinating tetrathiafulvalene (TTF) derivatives: electronic conductivity. Two approaches have been studied to promote an efficient conductivity pathway. In a first part, a series of symmetrical coordinating TTFs bearing thioether-pyridine or thio-pyridine spacers were synthesized. These TTFs were then employed for the formation of interpenetrated systems to generate stacks of electro-active moieties in the solid state. In a second part, a dissymmetrical TTF was developed and implemented in an alternative approach involving the formation of stacks of sulfur-rich units through interdigitation. This strategy allowed the synthesis of two isostructural materials. Studies of the oxidation state of the TTF within the networks were performed by EPR spectroscopy, followed by measurements of the electronic conductivity of these networks. In a third part, the interdigitation approach has been successfully extended to homo and heteroleptic dithiolene complexes
Nunes, Domschke Tamara. "P-doped semiconducting polymers : process optimization, characterization and investigation of air stability." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSES020.
Full textOrganic semiconductors (OSCs) are promising materials for low-cost, flexible, large-area production of printed electronic devices. In this context, molecular doping allows controlling the electrical properties of OSCs, offering a powerful tool to improve the performances of different electronic devices. Despite the progress in the fundamental understanding of the doping mechanism and processing techniques, stability aspects of p-doped OSCs have received little attention. Nevertheless, the stability of the p-doped state in the presence of oxygen and humidity is a crucial factor to be investigated for the integration of doped layers in organic devices.In this thesis, we have studied the molecular doping of disordered polymer semiconductors and the stability of the p-doped state in the presence of oxygen and water-related species. PBDTTT-c and RRa-P3HT were used as polymer hosts and F4TCNQ and Mo(tfd-COCF3)3 as p-dopants. The process conditions have been carefully studied to achieve controlled doping and to optimize the electrical properties. The impact of the dopant concentration was investigated in terms of electrical (conductivity), optical (UV-Vis-NIR) and structural (GIWAXS) properties of doped layers.The stability of the p-doped state was investigated by monitoring the evolution of the doping signatures under three different atmospheres: argon, anhydrous air, and ambient air. XPS analyses were carried out to investigate the impact of air exposure on the chemical state of p-doped layers. Simulations have been used to support our findings.Present results highlighted the presence of an important dedoping mechanism for p-doped semiconducting polymers in the presence of water-related species
Ismaili, Jihane. "Synthèse de nouveaux polymères pour l’élaboration d’un papier semi-conducteur." Thesis, Limoges, 2016. http://www.theses.fr/2016LIMO0097/document.
Full textThe use of organic semiconductors in electronic devices offers interesting prospects. Indeed, they make it possible to lighten the weight of these devices in addition to greatly reducing the cost of their manufacture. However, one of the main problems associated with these organic semiconductors is their manufacturing process, which requires toxic organic solvents and multiple synthesis steps. In this work, a new environmentally friendly synthesis process has been developed. A single step was necessary for the preparation of the semiconductors, using the polycondensation reaction between a diamine and a dialdehyde.This reaction was carried out at room temperature in ethanol, a green solvent and without the use of catalysts, thus minimizing energy consumption and using a reaction medium from a renewable and low-toxicity source. After their doping, these polymers exhibited conduction properties comparable to those observed for conventional organic semiconductors.The second part of this thesis was devoted to the study of the use of paper as a support for organic electronics devices; hus avoiding the use of generally non-biodegradable and/or non-renewable substrates (plastic or glass). Two strategies have been used to this end. The first consisted of a direct deposit of the semiconducting polymers to the surface of cellulose filaments.The second is based on the creation of a covalent bond between the semiconductors and the Kraft pulp, using the copper-catalyzed Huisgen 1,3-dipolar cycloaddition reaction (CuAAc)
Bessi, Matteo. "DEVELOPMENT OF NEW HIGHLY CONJUGATED MOLECULES AND THEIR APPLICATION IN THE FIELD OF RENEWABLE ENERGY AND BIOMATERIALS." Doctoral thesis, Università di Siena, 2018. http://hdl.handle.net/11365/1066871.
Full textIn recent years hybrid functional materials began to be employed in a series of technologically advanced applications spanning from bio/medical sensors, to renewable energy generation. For this reason, they became the focus of several studies in the field of materials science. At the same time, conjugated molecules have also been intensively investigated, due to the properties arising by the presence of long π-conjugated systems, from the possibility to conduct electricity to the ability to absorb light in a wide range of wavelengths. This PhD work focused on the introduction of such systems in two different kinds of hybrid materials, namely photovoltaic devices for the production of electricity (in particular Dye Sensitzed Solar Cells) and alternative fuels hydrogen), and biocompatible stimuli-responsive hydrogels (capable to conduct electricity and to react upon irradiation), and on the study of their influence on the characteristics of the final material.
Ces dernières années, les matériaux fonctionnels hybrides ont commencé à être employés pour des applications de la haute technologie, allant des senseurs bio/médicaux, à la production d’énergie renouvelable. Pour cette raison, ils sont devenus le centre de plusieurs études dans le domaine des sciences des matériaux. Simultanément, des molécules conjuguées ont été examinée intensément à cause de leurs propriétés venant de leurs longs systèmes π, allant de la possibilité de conduire l’électricité, à leur capacité d’absorber la lumière dans une grande fenêtre spectrale. Le travail de cette thèse se concentre sur l’introduction de tels systèmes dans deux sortes de matériaux hybrides, les dispositifs photovoltaïques pour la production d’électricité (en particuliers les cellules solaires à pigment photosensible) et de carburants alternatifs (hydrogène), et pour les hydrogels biocompatibles sensibles aux stimuli (capables de conduire l’électricité et de réagir sous irradiation), et sur l’étude de leur influence sur les caractéristiques du matériau final.
Bessi, Matteo. "Development of new highly conjugated molecules and their application in the field of renewable energy and biomaterials." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAF056/document.
Full textIn recent years hybrid functional materials began to be employed in a series of technologically advanced applications spanning from bio/medical sensors, to renewable energy generation. For this reason, they became the focus of several studies in the field of materials science. At the same time, conjugated molecules have also been intensively investigated, due to the properties arising by the presence of long π-conjugated systems, from the possibility to conduct electricity to the ability to absorb light in a wide range of wavelengths. This PhD work focused on the introduction of such systems in two different kinds of hybrid materials, namely photovoltaic devices for the production of electricity (in particular Dye Sensitzed Solar Cells) and alternative fuels (hydrogen), and biocompatible stimuli-responsive hydrogels (capable to conduct electricity and to react upon irradiation), and on the study of their influence on the characteristics of the final material
Boukhris, Abdallah. "Étude par diffraction des rayons X des porphyrines de gallium, germanium et indium, synthons potentiels de conducteurs électriques unidimensionnels." Nancy 1, 1986. http://www.theses.fr/1986NAN10038.
Full textNguyen, Thi Thao. "Synthèse et étude de dérivés porteurs du motif 1,3-dithiole-2-ylidene actifs en optique non linéaire de deuxième et troisième ordre." Angers, 1996. http://www.theses.fr/1996ANGE0003.
Full textLopez, Cruz Nazario. "Tuning the Properties of Molecular Magnets and Conductors Based on Lanthanide and Transition Metal Ions Bridged by TCNQ Derivatives or Cyanometallate Ligands by Varying the Dimensionality of the Structure and Metal Ion Identity." Thesis, 2010. http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7818.
Full textBardagot, Olivier. "Semi-conducteurs organiques de type n pour la conversion d'énergie." Thesis, 2019. http://www.theses.fr/2019GREAV027.
Full textAt a time when the impacts of climate change have become undeniable, the development of low-carbon energies is crucial. Potentially low cost compared to established technologies, emerging organic technologies offer an eco-efficient alternative for harvesting solar and thermal (< 473 K) energies. In the first chapter, the advantages and drawbacks of the different technologies currently being developed are discussed. Photovoltaic devices, like thermoelectric devices, require two types of materials conducting holes (p type) and electrons (n-type) respectively. Despite remarkable advances, the development of n-type semiconductors represents a major lever for improving organic technologies. In this context, this doctoral work presents the design, synthesis, characterization and device developments of innovative pi-conjugated n-type polymers and small molecules.Based on three electron-accepting units – isoindigo (ISI), naphthalene diimide (NDI) and fluorinated benzodifurandione-oligo(p-phenylenevinylene) (FBDOPV) – the design and synthesis of alternated copolymers are presented in the second chapter. These polymers exhibit high electron affinities ranging from 3.5 eV to 4.1 eV. DFT modelling and thin-film X-ray diffraction studies allowed to identify the main structural aspects leading to electron mobility as high as 0.26 cm2.V 1.s 1 achieved in organic field effect transistors.For thermoelectricity, molecular doping of these organic semiconductors is required. It is the subject of the third chapter. The necessary conditions for thermo- and photo-activation of N DMBI dopant have been identified. In particular, the degradation of the activated dopant in the presence of oxygen has been demonstrated by single crystal X-ray diffraction. Each polymer and two small molecules based on ISI and NDI cores have successfully being doped. The doping mechanisms and conductivities obtained are discussed on a case by case basis using UV-Visible-Near-Infrared and Electron Paramagnetic Resonance spectroscopies. In particular, conductivities in the range of 10-4 S.cm-1 were obtained without external energy supply neither before nor after deposition. Encouraging conductivities in the range of 10-3 S.cm 1 for a small molecule based on NDI and 10-2 S.cm 1 for a polymer based on FBDOPV have been achieved. The stability and reversibility of thin film conductivities when exposed to air were investigated and correlated to the LUMO level of the materials. The thorough control of deposition and doping conditions have afforded to achieve a power factor of about 0.3 µW.m-1.K-2 associated to a thermal conductivity of 0.53 W.m 1.K 1. Figure of merits of approximately 2.10-4 at 303 K and 5.10-4 at 388 K have been obtained, which represent the first values reported to date for an n-doped organic semiconductor measured on a single device.These materials also allow the replacement of fullerene derivatives in photovoltaic devices as presented in the last chapter. In particular, they demonstrate strong absorption properties, extended to the near infrared domain for one of the polymers. A conversion efficiency of 1.3% was obtained in all polymer bulk-heterojunction solar cell before optimization. Following the donor-spacer-acceptor approach, two ITIC derivatives have been designed and characterized. The modification of alkyl substituents on the spacer provides improved absorption and molecular packing properties compared to ITIC. High open-circuit voltages up to 1.10 V and conversion efficiencies of 4.2% have been achieved with these non-fullerene acceptors
Brunner, Pierre-Louis Marc. "Dispositifs optoélectroniques à base de semi-conducteurs organiques en couches minces." Thèse, 2015. http://hdl.handle.net/1866/16002.
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