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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

A Search For the Standard Model Higgs Boson Produced in Association with Top Quarks in the Lepton + Jets Channel at CMS

Smith, Geoffrey N. 18 August 2014 (has links)
No description available.
12

STUDY OF THE EFFECT OF STERIC BULK OF SIDE CHAINS ON THE PROPERTIES OF CONJUGATED POLYMERS

Zhang, Bei 01 January 2018 (has links)
Donor-acceptor conjugated polymers opened a new era for conjugated polymer research due to the abundant selection and combination of different conjugated units. This class of polymers function as semiconductor materials with potential application in plastic consumer electronics. The frontier molecular orbital energies of the polymers are generally determined by the selection of donor and acceptor units in the backbone structure, and their substituents. The side chains attached to the backbone not only affect the solubility of the materials, but also their self-assembly and morphological characteristics, which indirectly govern optoelectronic properties. It is important therefore to consider backbone architectures and the side chains together, to control (opto)-electronic properties for specific applications, while also maintaining solution processability without disrupting solid-state packing. The research presented in this dissertation focuses largely on the side chains: how the bulk and position of side chains affect the (opto)-electronic properties of select donor-acceptor (D-A) conjugated polymers. More precisely the intent is to vary the size and position of branches in the alkyl side chains of donor-acceptor polymers, in the attempt to solubilize poorly soluble polymers, without disrupting self-assembly of the polymer backbones into close p-stacks. After an introductory chapter 1, chapter 2 mainly focuses on the synthesis and structure-property study of polymers with 2,3,5,6-tetrafluorobenzene (TFB) as the acceptor motif and benzo[1,2-b:4,5-b′]dithiophene (BDT) as donor units carrying solubilizing substituents. TFB units were chosen based on previous observations that this acceptor unit imparts particularly poor solubility to various donor-acceptor copolymers. The current study indicates that bulky branches placed close to the polymer backbone could solubilize the PBDTTFB copolymers without altering the absorption profile and oxidation potentials. Optical, wide-angle x-ray diffraction (WAXD) and solubility studies shows that solubility is closely related to branching size and position. As the branch size in increased, the solubility of these polymers undergoes a step-change. The third chapter mainly focuses on the structure-property study of D-A polymers with thienopyrroledione (TPD) as acceptor. Unlike TFB, this acceptor can carry additional side chains that can compete with the space-filling demands of the donor unit side chains. As donor, the rigid BDT unit was compared with 3,3’-dialkoxy-2,2’bithiophene (RO2T2) units which have a similar size, but contain a “swiveling” central σ-bond. Bulkiness of side chains attached to the T2 units should be expected to have a more severe impact, possibly causing the two thiophene units of the T2 units to twist out of plane. It was demonstrated that alkoxy side chains with bulky branches in close proximity to the polymer backbones does not disrupt conjugation in these polymers. The UV-Vis absorption spectra of RO2T2-TPD polymers were red-shifted (more than 120 nm) in comparison to PBDTTPD polymers due to the smaller Eg (energy gap), which might be attributed to the expected higher energy HOMO imparted by the donor unit. The π-π stacking of polymers with BDT units was little affected by the bulky side chains. However, the π-π stacking of polymers with RO2T2 units was much more sensitive to side-chain bulk, with high degree of order and close π-π stacking only if proper local free spacing exists for side-chain interdigitation. Chapter 4 reports efforts to study polymers from the same set of RO2T2 monomers studied in Chapter 3, but without acceptor units that might otherwise drive self-assembly. RO2T2 homopolymers were synthesized via the Grignard metathesis (GRIM) method. Further, copolymers were prepared with RO2T2 units alternating with thiophene, thieno[3,2-b]thiophene or bithiophene. The spectroscopic studies suggest these polymers with bulky side chains exhibit some varying level of backbone conjugation. Somewhat surprisingly, despite an expected decrease in the strength of intermolecular donor-acceptor interactions, the solubilities were in some cases low, but varied with volume fraction of side chains. Further, even for polymers that appear to easily dissolve, aggregation in solution is so extensive as to give ensembles “too large” for characterization by GPC and or solution NMR. Oxidation potentials seem essentially insensitive to any of the structural variables (governed mostly by the backbone RO2T2 units).
13

Insamling, rening och användning av vatten i den hållbara hemträdgården.

Wedrén, Malin January 2009 (has links)
<p>Utan vatten inget liv. Människor är beroende av rent vatten för sin överlevnad. I många länder orsakar idag bristen på rent vatten sjukdomar och för tidig död. Världens problem med sötvatten i form av brist och svåra föroreningar orsakade av människan kan te sig kolossala. Befolkningsökning och ändrade levnadssätt påverkar. Industrier och jordbruk har stor påverkan men också den enskilda människans vattenanvändning har betydelse.</p><p> </p><p>I Sverige tycks den allmänna inställningen vara att vi inte har ett problem med vårt användande av vatten. Men vid en närmare undersökning av vårt innanhav Östersjöns problem med exempelvis övergödning och syrebrist och utsläppen av näringsämnen ifrån våra enskilda avlopp kan man ställa sig frågande. Även svenskens nyttjande av grundvattenreserver kan te sig olämpligt utifrån ett ekologiskt hållbart perspektiv. Att sedan detta vatten renas till dricksvattenkvalitet för att sedermera användas till att vattna fuktälskande växter som är planterade i gassande sol i en sandig torr jord kan vara förbryllande. Medvetenhet utifrån det lilla perspektivet, till exempel den svenska hemträdgården, kan vara åskådligt. Samtidigt kan det kanske också bidra till en i framtiden miljövänligare politik där målet är att rent sötvattnen skall finnas tillgängligt för alla i ett långt perspektiv.</p><p> </p><p>I denna litteraturstudie, möjligheten till en rationell vattenanvändning i den privata hemträdgården ur ett ekologiskt hållbart perspektiv. Flertalet olika metoder att hushålla med vatten och att tillvarata, rena och använda sig av nederbörd och gråvatten belyses. Resultatet är indelat i två delar; hushållning och rening. I den första redogörs på vilka sätt en effektivisering av vattenanvändandet kan gå till. Lättast och effektivast görs detta genom att dra ner på förbrukningen. Detta går enkelt att göra med några få tekniker. Till exempel att bättra på jordstruktur med organisktmaterial, att placera växter på platser som liknar deras naturliga habitat, minska avdunstning och forma platsen så att nederbörd kan ledas dit den behövs. Att se över hur extrabevattning ska tillämpas på effektivast sätt samt vilken vattenkälla detta vatten kommer ifrån tillhör också detta hushållande stycke. I den andra delen redogörs för olika metoder som kan tillämpas i en trädgård för att rena grå- och dagvatten så att trädgårdens naturliga potential till att vara en del av jordens naturliga kretslopp främjas. Lättast görs detta genom en begränsning av föroreningar redan vid deras källa. Därefter kan infiltrationsytor, infiltrationsplanteringar, biodiken, gröna tak, dammar, konstruerade våtmarker, rotzoner, UV-ljus och aquakulturer vara mer eller mindre användbara metoder som kan tillämpas i hemträdgården.</p><p> </p><p>Vattenfrågan bör klarläggas redan vid planeringen av byggnader och trädgård. Varje tomt måste sättas in i sitt sammanhang då dessa unika med speciella förutsättningar och problem. Hemträdgården är en utmärkt plats för experiment och utvecklingsarbete av ett hållbart vattenanvändande.</p> / <p>Without water there would be no life on earth. People depend of clean water for their survival. Today in many countries the lack of clean water is causing disease and premature death. World problems with fresh water in the form of shortage and severe pollution caused by humans may seem colossal. Industries and agriculture have a major impact but also the individual’s water-use has consequences.</p><p> </p><p>In Sweden the public opinion seems to be that we do not have a problem with our use of water. But with a closer look on facts that is not the case. For example our inland sea, Östersjön, and our contribution to its problems with euthrophication, lack of oxygen with the spillage of nutrients from the sewers and agriculture. Also the Swedish use of ground water may seem inappropriate in an ecological sustainable perspective. What is even more puzzling is that this water gets cleaned to a drinking water quality and then gets used for watering plants in the garden or to wash the car. Consciousness from the small perspective (as the Swedish private garden) can contribute to a future environmentally friendly politic that will lead to a sustainable water-use in a long perspective.</p><p> </p><p> </p><p>With this paper I would like to demonstrate, in a literature study, the possibility of a rational water-use in the private home garden from an ecological sustainable perspective.  Different methods of economising the water-use, gathering and cleaning stormwater and greywater will be illustrated. The result part will be divided into two parts; economization of water and cleaning of water.</p><p> </p><p>The first part describes the ways in which an efficiency of water-use can be preceded. The easiest way this is done is to cut down the consumption of water. This can easily be done with a few techniques. For example to improve the soil structure with organic material, placing of plants in places that resemble their natural habitat, reduction of evaporation and shaping pf the site so that precipitation can be managed where it is needed. Also to in which way irrigation is applied in the most efficient way and from which source this water is taken is presented in this part. The second part describes different methods of cleaning grey- and stormwater so the home garden’s natural potential to be a part of the earth’s natural rhythm is promoted.</p><p>Most easily this is done by stopping the pollution at the source. After that infiltration areas, bioswales, green roofs, ponds, constructed wetlands, reed beds, UV light and aquacultures can be more or less potential methods to be applied in the home garden.</p><p> </p><p>Water issues should be clarified already at the design process with homes and gardens. Each plot and garden is unique with its particular conditions and problems. Therefore needs every case to be seen in its particular context in order to obtain the optimal solution for that particular place.The home garden is a suitable place for experimental development of a sustainable water-use.</p>
14

Insamling, rening och användning av vatten i den hållbara hemträdgården.

Wedrén, Malin January 2009 (has links)
Utan vatten inget liv. Människor är beroende av rent vatten för sin överlevnad. I många länder orsakar idag bristen på rent vatten sjukdomar och för tidig död. Världens problem med sötvatten i form av brist och svåra föroreningar orsakade av människan kan te sig kolossala. Befolkningsökning och ändrade levnadssätt påverkar. Industrier och jordbruk har stor påverkan men också den enskilda människans vattenanvändning har betydelse.   I Sverige tycks den allmänna inställningen vara att vi inte har ett problem med vårt användande av vatten. Men vid en närmare undersökning av vårt innanhav Östersjöns problem med exempelvis övergödning och syrebrist och utsläppen av näringsämnen ifrån våra enskilda avlopp kan man ställa sig frågande. Även svenskens nyttjande av grundvattenreserver kan te sig olämpligt utifrån ett ekologiskt hållbart perspektiv. Att sedan detta vatten renas till dricksvattenkvalitet för att sedermera användas till att vattna fuktälskande växter som är planterade i gassande sol i en sandig torr jord kan vara förbryllande. Medvetenhet utifrån det lilla perspektivet, till exempel den svenska hemträdgården, kan vara åskådligt. Samtidigt kan det kanske också bidra till en i framtiden miljövänligare politik där målet är att rent sötvattnen skall finnas tillgängligt för alla i ett långt perspektiv.   I denna litteraturstudie, möjligheten till en rationell vattenanvändning i den privata hemträdgården ur ett ekologiskt hållbart perspektiv. Flertalet olika metoder att hushålla med vatten och att tillvarata, rena och använda sig av nederbörd och gråvatten belyses. Resultatet är indelat i två delar; hushållning och rening. I den första redogörs på vilka sätt en effektivisering av vattenanvändandet kan gå till. Lättast och effektivast görs detta genom att dra ner på förbrukningen. Detta går enkelt att göra med några få tekniker. Till exempel att bättra på jordstruktur med organisktmaterial, att placera växter på platser som liknar deras naturliga habitat, minska avdunstning och forma platsen så att nederbörd kan ledas dit den behövs. Att se över hur extrabevattning ska tillämpas på effektivast sätt samt vilken vattenkälla detta vatten kommer ifrån tillhör också detta hushållande stycke. I den andra delen redogörs för olika metoder som kan tillämpas i en trädgård för att rena grå- och dagvatten så att trädgårdens naturliga potential till att vara en del av jordens naturliga kretslopp främjas. Lättast görs detta genom en begränsning av föroreningar redan vid deras källa. Därefter kan infiltrationsytor, infiltrationsplanteringar, biodiken, gröna tak, dammar, konstruerade våtmarker, rotzoner, UV-ljus och aquakulturer vara mer eller mindre användbara metoder som kan tillämpas i hemträdgården.   Vattenfrågan bör klarläggas redan vid planeringen av byggnader och trädgård. Varje tomt måste sättas in i sitt sammanhang då dessa unika med speciella förutsättningar och problem. Hemträdgården är en utmärkt plats för experiment och utvecklingsarbete av ett hållbart vattenanvändande. / Without water there would be no life on earth. People depend of clean water for their survival. Today in many countries the lack of clean water is causing disease and premature death. World problems with fresh water in the form of shortage and severe pollution caused by humans may seem colossal. Industries and agriculture have a major impact but also the individual’s water-use has consequences.   In Sweden the public opinion seems to be that we do not have a problem with our use of water. But with a closer look on facts that is not the case. For example our inland sea, Östersjön, and our contribution to its problems with euthrophication, lack of oxygen with the spillage of nutrients from the sewers and agriculture. Also the Swedish use of ground water may seem inappropriate in an ecological sustainable perspective. What is even more puzzling is that this water gets cleaned to a drinking water quality and then gets used for watering plants in the garden or to wash the car. Consciousness from the small perspective (as the Swedish private garden) can contribute to a future environmentally friendly politic that will lead to a sustainable water-use in a long perspective.     With this paper I would like to demonstrate, in a literature study, the possibility of a rational water-use in the private home garden from an ecological sustainable perspective.  Different methods of economising the water-use, gathering and cleaning stormwater and greywater will be illustrated. The result part will be divided into two parts; economization of water and cleaning of water.   The first part describes the ways in which an efficiency of water-use can be preceded. The easiest way this is done is to cut down the consumption of water. This can easily be done with a few techniques. For example to improve the soil structure with organic material, placing of plants in places that resemble their natural habitat, reduction of evaporation and shaping pf the site so that precipitation can be managed where it is needed. Also to in which way irrigation is applied in the most efficient way and from which source this water is taken is presented in this part. The second part describes different methods of cleaning grey- and stormwater so the home garden’s natural potential to be a part of the earth’s natural rhythm is promoted. Most easily this is done by stopping the pollution at the source. After that infiltration areas, bioswales, green roofs, ponds, constructed wetlands, reed beds, UV light and aquacultures can be more or less potential methods to be applied in the home garden.   Water issues should be clarified already at the design process with homes and gardens. Each plot and garden is unique with its particular conditions and problems. Therefore needs every case to be seen in its particular context in order to obtain the optimal solution for that particular place.The home garden is a suitable place for experimental development of a sustainable water-use.
15

Search for neutral bosons decaying into the fully hadronic di-tau final state with the ATLAS detector at the LHC

Duschinger, Dirk 26 April 2019 (has links)
This thesis presents a search for neutral bosons, such as new Higgs and Z' bosons, predicted by theories extending the Standard Model of particle physics. The search is performed in the di-tau analysis channel, where both tau leptons decay hadronically. Promising candidates of such theories are the Minimal Supersymmetric Standard Model (MSSM) and the non-universal G(221) model, which predict large couplings to tau leptons in large regions of their parameter space. Proton–proton collisions produced by the Large Hadron Collider (LHC) at a center-of-mass energy of 13 TeV, recorded with the ATLAS detector in 2015 and 2016, are analyzed for this search. The data correspond to an integrated luminosity of 36.1 fb^-1. This search relies on sophisticated algorithms for the reconstruction of hadronic tau decays from their decay products. This thesis presents a novel approach employing multivariate techniques to significantly improve existing algorithms, which became the default for reconstruction of hadronic tau decays in ATLAS since 2017. Additionally, the new method can provide useful information for subsequent tau identification algorithms. The MSSM extends the Higgs sector of the Standard Model by four additional Higgs bosons. Of particular interest for this thesis are the neutral CP-even H and CP-odd A bosons. The search for these bosons is performed in the mass range of 0.2 TeV to 2.25 TeV in two orthogonal categories depending on the number of identified b-quarks, each preferring one of the two considered production modes via gluon–gluon fusion or b-associated production. The data are in good agreement with the Standard Model prediction. Upper limits are set on the cross-section times branching fraction using a confidence level (CL) of 95 % independently for both production modes. Most stringent observed limits are found for a resonance mass of 1.5 TeV to be 4.94 fb and 3.65 fb for gluon–gluon fusion and b-associated production, respectively. The results are further interpreted in the hMSSM, mhmax and mhmod scenarios. Observed upper limits in the hMSSM scenario on tanβ are found to be between 4.6 at mA = 0.25 TeV and 41.4 at mA = 1.5 TeV. The search for additional Z' bosons is performed independently on the number of identified b-quarks in the mass range of 0.2 TeV to 4 TeV. As for the search for additional Higgs bosons no significant hint for new physics has been observed. 95 % CL observed upper limits are set on the cross-section times branching fraction for Z' bosons in the Sequential Standard Model (SSM) benchmark scenario between 20.5 pb at mZ' = 0.2 TeV and 7.74 fb at mZ' = 1.75 TeV. The observed upper limit for the highest considered mass of mZ' = 4 TeV is found to be 16 fb. Z' bosons in the SSM and the non-universal G(221) model are excluded at 95 % CL for masses below 2353 GeV and 2232 GeV, respectively.
16

Recherche de résonances W' → tb dans le canal lepton plus jets avec le détecteur ATLAS au LHC / Search for W' → tb in the lepton plus jets channel with the ATLAS detector at the LHC

Gilles, Geoffrey 28 May 2015 (has links)
Le travail de recherche réalisé au cours de cette thèse s’inscrit dans le contexte de l’expérience ATLAS, l’une des quatre grandes expériences auprès du collisionneur LHC. Il fut principalement dédié à la recherche de nouveaux bosons de jauge lourds chargés, appelé W' et prédits par de nombreuses extensions du Modèle Standard de la physique des particules. Ce manuscrit présente une recherche du boson W' se désintégrant en un quark top et un quark beau à travers une approche de couplage effectif, dans des états finals de désintégrations leptoniques du quark top. Cette recherche fut réalisée avec 20.3 fb−1 de données de collision proton-proton, produits par le LHC à une énergie dans le centre de masse de 8 TeV et collectées par le détecteur ATLAS en 2012. Plusieurs scénarios d’études sont envisagés où le boson W' se couple soit à des fermions de chiralité gauche (W'L) soit de chiralité droite (W'R). Une technique d’analyse multivariée utilisant des arbres de décision boostés (BDT) est utilisée afin de mettre évidence un excès de processus de signal dans les données enregistrées. Aucun excès n’est observé au-delà des incertitudes expérimentales pour la statistique de données analysées jusque-là. Une analyse statistique est réalisée afin d’extraire des limites d’exclusion sur la masse et la section efficace de production de la particule. Des masses inférieures à 1.92, 1.80 et 1.70 TeV furent exclues respectivement pour des bosons W'R et W'L, en tenant compte ou non d’effets d’interférence. Les limites d’exclusion sur les sections efficaces de production sont réinterprétées en matière de limite d’exclusion sur le couplage effectif g'/g de la particule. Les limites d’exclusion les plus basses observées sur le rapport g'/g, respectivement de 0.20 et 0.16 pour les recherches de bosons W'R et W'L, furent obtenues pour une masse de boson W'R/L de 0.75 TeV. Une recherche de bosons de Higgs chargés se désintégrant en un quark top et un quark beau est également présentée dans ce manuscrit. Cette dernière repose sur une approche de couplage effectif décrivant un modèle à deux doublets de Higgs de type II. Cette analyse réutilise l’infrastructure développée pour la recherche du boson W' est complétée d’études phénoménologiques liées au calcul de la section efficace de ce processus ainsi que sur la caractérisation des effets de largeur de la résonance recherchée. Les premiers résultats obtenus sur la limite d’exclusion sur la section efficace de production pp → H+→ tb montrent toutefois que cette analyse ne semble pas être en mesure d’exclure un signal de boson H+ pour l’ensemble des scénarios théoriques considérés, compte tenu des faibles sections efficaces de production prédites. En parallèle de ces activités, des développements ont été réalisés pour la simulation rapide du système de calorimétrie FastCaloSim du détecteur ATLAS afin de pallier ses limitations. En particulier, un nouveau modèle de paramétrisation et de simulation rapide de la réponse en énergie du système de calorimétrie est présenté dans ce manuscrit. Ce modèle, toujours en développement, montre des résultats très encourageant pour la simulation d’événements à pion unique et permet de réduire considérablement l’empreinte mémoire de la paramétrisation en comparaison avec des versions précédentes de FastCaloSim, tout en permettant aux futures reparamétrisations d’être plus rapides et automatisées. / The research work carried out during this Ph.D thesis has been performed in the context of the ATLAS experiment, one of the four major LHC experiments, and was primarily dedicated to the search for a new chaged heavy gauge boson, called W' and predicted by many extensions of the Standard Model of particle physics. This manuscript presents a search for W' boson decaying into a top and a bottom quark through an effective coupling approach, in the lepton plus jets final states. This search is performed with 20.3 fb−1 of proton-proton collision data, produced by the LHC with a center-of-mass energy of 8 TeV and collected by the ATLAS detector in 2012. Several scenarios are considered where the W boson can couple to left-handed (W'L) or right-handed (W'R) fermions. A multivariate techniques based on boosted decision trees is used to search for an excess of W signal process in the recorded data. No excess is observed beyond the experimental uncertainties for the data analysed so far. A statistical analysis is performed in order to extract exclusion limits on the mass and the production cross section of the particle. Masses below 1.92, 1.80 and 1.70 TeV are excluded, respectively for W'R and W'L bosons taking into account or not interference effects. These exclusion limits on the production cross section are also reinterpreted in terms of exclusion limits on the effective coupling g'/g of the particle. The lowest exclusion limits observed on the ratio g'/g are equal to 0.20 and 0.16, respectively, for W'R and W'L searches, and are obtained for a W'R/L mass of 0.75 TeV. A search for charged Higgs boson decaying into a top and a bottom quark is presented in this manuscript. This search is based on an effective coupling approach describing a type II Two Doublet Higgs Model. It reuses the analysis infrastructure developed for the W' search and is completed by phenomenological studies related to the production cross section calculation for the process and the characterisation of the resonance width effects affecting the analysis. Preliminary results on the excluded cross section limits pp → H+→ tb show that the analysis is not able to exclude a signal a H+ boson for all theoretical scenarios considered, due to low production cross sections predicted. In parallel of these activities, several developments have been performed on the fast simulation of the ATLAS calorimeter system in order to overcome its limitations. In particular, a new parametrisation and fast simulation model for the energy response of the calorimeter is presented in this manuscript. This model, still under development, shows encouraging results for simulated single pion event and allows to reduce considerably the memory footprint of the parametrisation compared to previous versions of FastCaloSim, while enabling future reparametrisations to be faster and automated.
17

Photovoltaïque organique : étude de la morphologie de films minces, conception, synthèse et étude de petites molécules pour leur utilisation en hétérojonction en volume dans des dispositifs photovoltaïques / Organic photovoltaics : study of thin films morphology, design, synthesis, synthesis of new small molecules and their study in bulk heterojunction devices

Hernandez Maldonado, Daniel 16 July 2015 (has links)
Les propriétés des matériaux organiques pour l'optoélectronique à base de polymères ou de petites molécules sont fortement influencées par l'organisation moléculaire. En particulier, l'efficacité de la photoconversion dans les dispositifs à base de films minces organiques peut être corrélée directement à la morphologie de leurs mélanges actifs. Par conséquent, une meilleure compréhension de l'évolution de la morphologie des films minces pendant les divers traitements effectués lors de leur élaboration est essentielle et nécessaire. D'autre part, l'ingénierie moléculaire est un outil crucial pour l'obtention de molécules basées sur des alternances de fragments accepteurs d'électrons ou donneurs d'électrons et présentant des valeurs de gap électronique optimales et conduisant à des dispositifs aux paramètres de photoconversion optimisés.Dans le présent travail, nous présentons une étude approfondie en solution et sur des films minces de poly-3-hexylthiophène (P3HT) pur et en mélange avec des complexes de nickel (Ni-bdt). Le but était de comprendre comment le P3HT interagit avec les complexes de nickel pour contrôler des phénomènes d'organisation éventuels. L'objectif principal de cette étude est de comprendre l'organisation moléculaires au sein des films organiques et son impact sur le transfert de charge entre les matériaux afin d'optimiser les rendements de photoconversion. En outre, nous avons conçu et synthétisé trois nouvelles molécules à faible gap électronique, nommées SilOCAO, Bz(T1CAO)2 et Bz(T1CAEH)2 selon des méthodologies de synthèse optimisées. Ces molécules ont été conçues avec l'appui de calculs semi-empiriques effectués avec le programme Gaussian 09 au niveau B3LYP/6-31G* dans le but de les associer éventuellement aux complexes de nickel. Leurs synthèses et caractérisations complètes sont décrites en détail. Les techniques analytiques utilisées sont la spectroscopie d'absorption UV-visible, la photoluminescence, la résonance magnétique nucléaire (RMN), la spectroscopie de masse, l'électrochimie, l'analyse thermogravimétrique (TGA) et la calorimétrie différentielle à balayage (DSC). Ces molécules présentant des propriétés intéressantes pour leur utilisation en photovoltaïque organique, nous avons réalisé des cellules solaires organiques prototypes. Les résultats obtenus sont prometteurs, en particulier dans le cas de la molécule SilOCAO, utilisée ici comme donneur d'électrons en association avec le PC71BM. Ce travail est le fruit d'une collaboration précieuse entre plusieurs chercheurs, des théoriciens et expérimentateurs, des laboratoires LAAS et LAPLACE à Toulouse (France), de l'Université Autonome Nationale de Mexico (UNAM) et du Centre de Recherche en Optique (CIO) de Leon (Mexique). / Optoeletronic properties of semiconducting polymeric/small molecules materials are highly influenced by molecules organization. In particular, photoconversion efficiency of organic devices may be correlated directly with their blend morphology. Therefore, a better understanding of the blend film morphology evolution during postproduction treatment and device performance is essential and needed. On the other hand, molecular engineering is a good way to module the band gap of molecules by alternating different electron acceptor or electron donor moieties which may lead to an improved internal charge transfer and a low band gap to achieve important Voc and Jsc, and consequently a good OPV performance. In the present work, we present a comprehensive study in solution and on thin films of pristine P3HT and of some nickel bisdithiolene complexes (Ni-bdt), and their blends, in order to understand how poly(3-hexylthiophene) P3HT interacts with the nickel core with the aim of understanding eventual organization phenomena. The main goal of this study is to understand materials organization and the charge transfer effect between donor and acceptor molecules, rather than focalize on a high photoconversion yields. In addition, we have developed 3 new low band gap small molecules, SilOCAO, Bz(T1CAO)2 and Bz(T1CAEH)2 with innovating synthetic methodologies and interesting applications to be used in thin film bulk heterojunctions (BHJs) for organic photovoltaics. These molecules were strategically designed via semi-empirical calculations (B3LYP/6-31G*) to match their energetic levels (LUMO and HOMO) with those of nickel bisdithiolene family towards a performing charge transfer. The syntheses of SilOCAO, Bz(T1CAO)2 and Bz(T1CAEH)2 have been described. These molecules have been fully-characterized by different techniques such as UV-Visible Spectroscopy, Electroluminescence, Nuclear Magnetic resonance (NMR), Mass Spectroscopy (MS), Electrochemistry, Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). Moreover, we have performed organic solar cells prototypes with some promising results, specifically for SilOCAO as the electron-donor in counterpart of the PC71BM as the electron-acceptor. This work is a fruitful collaboration between several laboratories, researchers, technical servers and students from LAAS and LAPLACE in France, and IIM (UNAM) and CIO in Mexico.

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