Humidity measurement has been increasingly important in many industries and process control applications. This thesis research focus mainly on humidity sensor calibration and characterization. The humidity sensor instrumentation is briefly described. The testing infrastructure was designed for sensor data acquisition, in order to compensate the humidity sensor’s temperature coefficient, temperature chambers using Peltier elements are used to achieve easy-controllable stable temperatures. The sensor characterization falls into a multivariate interpolation problem. Neuron networks is tried for non-linear data fitting, but in the circumstance of limited training data, an innovative algorithm was developed to utilize shape preserving polynomials in multiple planes in this kind of multivariate interpolation problems.

In this study, forced cooling of heat sinks mounted on CPU&rsquo / s was investigated. Heat sink effectiveness, effect of turbulence models, effect of radiation heat transfer and different heat sink geometries were numerically analyzed by commercially available computational fluid dynamics softwares Icepak and Fluent. The numerical results were compared with the experimental data and they were in good agreement. Conjugate heat transfer is simulated for all the electronic cards and packages by solving Navier-Stokes equations. Grid independent, well converged and well posed models were run and the results were compared. The best heat sink geometry is selected and it is modified in order to have lower maximum temperature distribution in the heat sink.

Le diamant est le semi-conducteur par excellence pour les composants électroniques de puissance. Par conséquent, la technique de croissance du diamant et les dispositifs à base de diamant ont été largement étudiés dans le monde entier au cours des deux dernières décennies. A ce jour, les diodes Schottky à base de diamant sont les composants les plus avancés et les plus prometteurs. Cependant, pour remplacer Si et SiC dans cette filière technologique, des progrès importants dans la technologie du diamant sont nécessaires.L'amélioration de l’électronique de puissance dépend non seulement des caractéristiques intrinsèques du semi-conducteur mais aussi de l'architecture du dispositif. Les dispositifs verticaux et pseudo-verticaux offrent nombreux avantages comme la faible résistance spécifique, la haute tension de rupture et une taille réduite. De plus, la conception tridimensionnelle (3D) permet de réduire le champ électrique à l'intérieur du matériau et de tirer parti des qualités exceptionnelles du diamant si le mécanisme de croissance de ce matériau sur un substrat structuré était plus étudié et mieux compris.Ainsi, le but de ce manuscrit de thèse est de comprendre les mécanismes qui régissent la reprise de croissance en homoépitaxie sur un substrat structuré 3D en diamant. Pour atteindre cet objectif, les principaux mécanismes de la croissance CVD sur substrat gravé sont étudiés expérimentalement par microscopie électronique en transmission grâce à une approche stratigraphique originale qui permet de suivre la direction de croissance et la génération de défauts aux différentes étapes de la croissance. L’observation de divers secteurs de croissance, d’une tendance générale à la planarisation, et le rôle important joué par la concentration de méthane qui gouverne la vitesse de croissance, sont les principaux résultats de cette étude. Divers modèles d’interprétation allant de l’échelle atomistique à l’échelle macroscopique sont discutés. L'origine des dislocations, et des autres défauts étendus et superficiels a été déterminée. Les basses concentrations de méthane ont permis une croissance 3D de haute qualité. La reprise de croissance sur des micro-terrasses est présentée comme une alternative pour l’obtention de grandes surfaces sans défauts. Une nouvelle méthode basée sur le renforcement par solution solide est introduite comme alternative à la cathodoluminescence pour évaluer le dopage dans les régions riches en dislocations, où les défauts empêchent l’observation d’excitons. Tous les résultats obtenus ont été pris en compte pour réduire le nombre d’étapes technologiques nécessaires pour fabriquer des composants à architecture 3D en diamant (diode Schottky ou même MOSFET). Dans le cas des diodes Schottky, le procédé et l’architecture proposés ont les avantages suivants :- « Filtrer » les dislocations.- Permettre d’étendre la région de champ arbitrairement.- Eviter certaines étapes de photolithographie.- Améliorer le contact ohmique, par croissance d’une couche p+ sur une facette {111}. / Diamond is the ultimate semiconductor for power electronic devices. Consequently, diamond growth techniques and diamond-base devices have been intensively investigated over the last two decades all over the world. Among these power devices, diamond based Schottky diodes are the most advanced. However, for diamond to substitute present Si and SiC for power electronics, a substantial technological progress is still needed.The improvement of power devices depends not only on the intrinsic characteristic of the semiconductor, but also on the device architecture. Vertical and pseudo-vertical devices offer many advantages such as low-specific on-resistance, high breakdown voltage and a smaller size. Moreover, three-dimensional (3D) design allows to reduce the electric field inside the material and would make the most out of the superb material qualities of diamond, if only the diamond growth mechanism over patterned diamond substrates would be better studied and understood.Thus, the aim of this thesis manuscript is to understand the mechanisms governing the three-dimensional (3-D) shaped diamond substrates homoepitaxial overgrowth, in order to implement them in the design and fabrication of a Schottky device.To reach this goal, the main mechanisms of CVD growth over patterned substrates were experimentally investigated by transmission electronic microscopy using a novel stratigraphic approach that allowed to follow the growth direction and generation of defects at various stages. Evidence was provided for many sectors of growth, and a tendency to planarization, while the methane concentration and resulting growth rates were shown to be key parameters. Various interpretation models, from the atomistic to the macroscopic scale, were discussed. The origin of dislocations, and of other extended and superficial defects was determined. Low methane concentrations led to high quality 3-D overgrowth. The overgrowth of micro-terraces is proposed as a method to achieve large areas free of defects. A novel method based in solid solution strengthening was introduced as an alternative to cathodoluminescence to evaluate boron doping in dislocation-rich regions where extended defects usually hinder this approach. All the results obtained above have been taken into account to reduce the number of technological steps leading to a diamond based 3D device (Schottky diode or even MOSFET). In the case of Schottky diodes, a 3D design was proposed with the following advantages:- To “filter” dislocations.- To allow an arbitrary large field region.- To spare photolithography steps.- To improve ohmic contacts, as the p+ layer is grown on a {111} facet.

abstract: With the penetration of distributed renewable energy and the development of semiconductor technology, power electronic devices could be utilized to interface re- newable energy generation and the distribution power grid. However, when directly connected to the power grid, the semiconductors inside the power electronic devices could be vulnerable to the power system transient, especially to lightning strikes. The work of this research focuses on the insulation coordination of power elec- tronic devices connected directly to the power distribution system. The Solid State Transformer (SST) in Future Renewable Electric Energy Delivery and Management (FREEDM) system could be a good example for grid connected power electronic devices. Simulations were conducted in Power Systems Computer Aided Design (PSCAD) software. A simulation done to the FREEDM SST showed primary re- sults which were then compare to simulation done to the grid-connected operating Voltage Source Converter (VSC) to get more objective results. Based on the simulation results, voltage surges caused by lightning strikes could result in damage on the grid-connected electronic devices. Placing Metal Oxide Surge Arresers (MOSA, also known as Metal Oxide Surge Varistor, MOV) at the front lter could provide eective protection for those devices from power transient. Part of this research work was published as a conference paper and was presented at CIGRE US National Conference: Grid of the Future Symposium [1] and North American Power Symposium [2]. / Dissertation/Thesis / Masters Thesis Engineering 2017

Ce mémoire est consacré à la conception et la caractérisation de molécules, matériaux et dispositifs électroniques commutables incorporant le système photochrome diméthyldihydropyrène (DHP) / cyclophanediène (CPD). La première partie est dédiée à la synthèse et à la caractérisation de photochromes originaux basés sur l'unité diméthyldihydropyrène. En particulier, la modification chimique de ce motif par des groupements électroattracteurs de type pyridinium induit une nette amélioration des cinétiques de conversion photoinduites tout en constituant une unité aisément fonctionnalisable. Dans une seconde partie, le motif photochrome est associé à des complexes métalliques dérivés du ligand terpyridine qui confèrent des propriétés rédox à l'architecture moléculaire. Ces assemblages sont mis en œuvre pour la conception de films minces organisés obtenus par auto-assemblage de métallopolymères sur des surfaces solides. Les complexes et les films étudiés possèdent des propriétés photochromes et une activité rédox particulièrement prometteuses pour la conception de matériaux et dispositifs moléculaires multicommutables. Enfin, nous présentons l'étude de la conductance des isomères DHP et CPD. Un dispositif électronique à molécule unique a ainsi été mis en œuvre en utilisant le motif photochrome fonctionnalisé par deux unités pyridine, utilisées comme fonctions d'ancrage dans le dispositif. Il apparaît que l'isomère DHP possède une conductance d'environ quatre ordres de grandeur supérieurs à celle de l'isomère CPD correspondant. Ces deux états peuvent être commutés de manière très reproductible par application de stimulus optiques et thermiques. / This thesis is devoted to the design and characterization of switchable molecular systems (molecules, materials and electronic devices) incorporating the dimethyldihydropyrene / cyclophanediene (DHP/CPD) photochromic couple. The first part deals with the synthesis and characterization of original photochromic molecules based on the dimethyldihydropyrene unit. In particular, the chemical functionalisation of these molecular systems with electron-withdrawal pyridinium groups leads to an improvement of the kinetics of photo-induced conversion while providing an easily functionalizable unit, for example with metal cations complexing units. In the second part, the photochromic core is covalently linked with metal complexes based on terpyridine derivatives, conferring redox-active properties to the molecular architecture. These assemblies are applied for the design of organized thin films obtained by self-assembly of metallopolymers on solid surfaces. The model complexes and films display photochromic properties and redox activity particularly promising for the design of responsive materials and molecular devices. Finally, we present the study of the conductance of the isomers DHP and CPD. A single molecule electronic device in which individual molecules are utilized as active electronic components has been implemented using the photochromic group functionalized with two pyridine units, used as anchoring functions. It appears that the DHP isomer has a conductance of about four orders of magnitude higher than the corresponding isomer CPD. These two states can be switched very reproducibly and reversibly upon application of optical and thermal stimulus.

Submitted by Luciana Sebin (lusebin@ufscar.br) on 2016-09-14T14:02:58Z No. of bitstreams: 1 TeseSFCR.pdf: 2145878 bytes, checksum: 25a0ab9d4040cd73e66e1592d64617c4 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-15T14:00:49Z (GMT) No. of bitstreams: 1 TeseSFCR.pdf: 2145878 bytes, checksum: 25a0ab9d4040cd73e66e1592d64617c4 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-15T14:00:55Z (GMT) No. of bitstreams: 1 TeseSFCR.pdf: 2145878 bytes, checksum: 25a0ab9d4040cd73e66e1592d64617c4 (MD5) / Made available in DSpace on 2016-09-15T14:01:03Z (GMT). No. of bitstreams: 1 TeseSFCR.pdf: 2145878 bytes, checksum: 25a0ab9d4040cd73e66e1592d64617c4 (MD5) Previous issue date: 2015-03-30 / Outra / The use of Magnetic Resonance Imaging (MRI) as a diagnostic imaging has grown every year due to its great benefits. MRI is a noninvasive test and decisiveness for diagnosis of various diseases and is widely used around the world. With the extension of human longevity, it is increasingly necessary to use new technologies for diagnosis and treatment of diseases. It is known that with increasing age, the individual develops certain diseases that require surgical correction resulting often the implant fixtures as, Cardiac Implantable Electronic Devices (DCEIs). Even though technologies that broke paradigms and transformed lives, extending life expectancy and facilitating diagnoses that were previously impossible and bad, these two medical advances were antagonists until recently, strictly forbidden and that patients with DCEI do use the examination RM due to the interference that this test could cause the DCEI and so harm the health of the patient. As this diagnostic imaging technology cannot be applied to most existing implants, it may be necessary to use alternatives with side effects or less valuable diagnostic information. Because it is an important and necessary for the progress of medical diagnostic advance, the potential risks and the influence of MRI on pacemakers have become research topic over the last ten years. As a result, we acquired a comprehensive understanding of the associated problems. This understanding and solutions to these problems have been integrated in the development of secure devices for MRI (MRI Pro). The objectives of this study were to determine if there is interference DCEI the image generated by Thoracic MRI and thus to understand their influence on the outcome of the review, and determine whether there were significant changes in the operation of this DCEI. Thoracic MRI was performed in 20 patients with DCEIs. The generated image, artifacts and pre and post test parameters were analyzed and compared; coming to the conclusion that Thoracic MRI in patients with DCEIs Pro MRI can be performed safely without changing the operation of the devices and without damaging the image of RM, since some rules and conditions are followed. / O uso da Ressonância Magnética (RM) como método de diagnóstico por imagem tem crescido a cada ano devido aos seus grandes benefícios. A RM é um exame não-invasivo e de caráter decisivo para diagnóstico de diversas doenças, sendo largamente usado ao redor do mundo. Com o prolongamento da longevidade humana, se faz cada vez mais necessário o uso de novas tecnologias para diagnóstico e tratamento de patologias. Sabe-se que com o avanço da idade, o indivíduo desenvolve certas doenças que necessitam correção cirúrgica acarretando, muitas vezes, o implante de dispositivos elétricos como, Dispositivos Cardíacos Eletrônicos Implantáveis (DCEIs). Mesmo sendo tecnologias que romperam paradigmas e transformaram vidas, prolongando a expectativa de vida e facilitando diagnósticos que antes eram impossíveis e duvidosos, esses dois avanços da medicina eram antagonistas até pouco tempo atrás, sendo terminantemente proibido que pacientes portadores de DCEI fizessem uso do exame de RM devido as interferências que este exame poderia causar no DCEI e assim prejudicar a saúde do paciente. Como essa tecnologia de diagnóstico por imagem não pode ser aplicada na maioria dos implantes existentes, pode ser necessário recorrer a alternativas com efeitos colaterais ou informações diagnósticas menos valiosas. Por se tratar de um avanço importante e necessário para o progresso da medicina diagnóstica, os riscos em potenciais e a influência do exame de RM sobre os marcapassos se tornaram tema de pesquisa no decorrer dos últimos dez anos. Como resultado foi adquirido um entendimento abrangente dos problemas associados. Este entendimento e as soluções para esses problemas foram integradas no desenvolvimento de dispositivos seguros para o exame de RM (Pro MRI). Os objetivos deste estudo foram determinar se existe interferência do DCEI na imagem gerada pela RM de Tórax e assim entender sua influência no resultado final do exame, e determinar se ocorreram alterações significativas no funcionamento desses DCEI. Foram realizados exames de RM de Tórax em 20 portadores de DCEIs. A imagem gerada, os artefatos e os parâmetros pré e pós exame foram analisados e comparados, chegando-se à conclusão de que o exame de RM de Tórax em portadores de DCEIs Pro RMI pode ser realizado com segurança, sem alterar o funcionamento dos dispositivos e sem prejudicar a imagem da RM, desde que algumas regras e condições sejam seguidas corretamente.

Este trabalho descreve o estudo de preparação dos filmes de polianilina, Pani, depositados pelo método de polimerização in-situ para serem utilizados em dispositivos poliméricos emissores de luz (PLEDs) e em sensores químicos e de flexão mecânica. É descrita a síntese química da Pani, a produção de filmes pelo método de polimerização in-situ, o estudo do seu crescimento usando a espectroscopia de UV-Vis e as características morfológicsa da superfície pela técnica de varredura de AFM. Filmes de Pani depositados pela técnica in-situ sobre eletrodos interdigitados foram caracterizados através de medidas de condutividade elétrica contínua e alternada em função da temperatura e da dopagem do material. Os resultados elétricos obtidos, típicos de sistemas sólidos desordenados, foram interpretados usando o modelo de condução de Dyre. Investigou-se o uso de filmes finos de Pani como camada injetora de portadores de carga em PLEDs para diferentes métodos de conversão do precursor poli(xilideno tetrahidrotiofeno), PTHT, em poli(-fenileno vinileno), PPV. Mostrou-se que a camada de Pani pode ser usada como janela transparente da emissão luminosa do PPV, o que diminui a tensão de operação do PLED e protege o eletrodo de ITO contra a corrosão durante o processo de conversão. São mostrados estudos exploratórios de sensores de Pani depositados sobre o substrato de poli (tereftalato de etileno) (PET) para aplicação em dispositivos para medidas de pH de solução e de flexão mecânica. / This work shows the study of Pani film prepared by the in-situ deposition technique aiming its use im polymeric light emission diodes (PLEDs) and in chemical sensors and of flection mechanics. The sysnthesis of the Pani, the production of films by the in-situ method, the film growth probed by UV-Vis spectroscopy and its surface morphology characteristics probed by the scanning AFM microscope are presented. Such in-situ films were deposited on the top of interdigitated electrodes and characterized usign ac and dc conductivity measurements as function of temperature and of the material doping level. The electric results were typical of non ordered materials and interpreted using the Dyre´s conduction model. It was investigated the use of Pani films as carrier layer injection in PLEDs employing different of conversion of poly(xylylidene tetrahydrothiophenium), PTHT, in to poly(-phenylene vinylene), PPV. It was showed that the Pani film act as a transparent window for the PPV light emission, the onset voltage of the PLED decreased and the Pani layers protects the ITO electrode against the corrosion during the conversion of the PTHT in to PPV. Exploratory studies were also performed using the Pani layer deposited on the top of a poly (ethylene terephtalate) substrate aiming its application for measuring the pH of a solution and as mechanical bending sensor.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / With the evolution in the radiation studies was noticed the precautions needed in the ionizing radiation applications due to the effects caused by this particles or waves interacting with the atoms as it pass through, the radiation energy deposited at certain point is known as absorbed dose. The dosimetry is a study that quantifies the dose values deposited by the radiations, this quantification is really necessary in medical applications as radiotherapy. In this work was studied the possibility to use the BC856 bipolar junction transistor in electron beam dosimetry, a radiation very common in superficial tumors treatment. The bipolar junction transistor is an electronic device that amplifies current in electric circuits; this characteristic is known as current gain. Some researches already indicated that this amplifier capacity is reduced when devices exposed to radiations, due to damage caused in the structures. The transistors studied presented slightly different current gain, even those from the same package, therefore was selected just the devices with similar gain. The transistors was irradiated by electron beans generated from a Varian linear accelerator Clinac iX, 6, 9 and 12 MeV beans was used in the tests. The collector current was measured before the irradiations and immediately after using an electrometer, to determinate the current gain reduction. It was possible to observe a linear relation between dose and damage caused in transistors. Even through the devices do not completely recover from the damages caused by radiation the devices apparent to be reusable. In the percentage dose deposited in different acrylic depth was possible no notice results from the transistors resembling the linear accelerator calibration data. It´s possible to conclude that the transistors studied may be used in megavoltage electron beam dosimetry due to the possibility to relate the damage caused in the devices and the dose absorbed by then. / Com a evolução nos estudos sobre radiação notou-se a necessidade de precauções com as aplicações das radiações ionizantes, devido aos efeitos que suas partículas e ondas eletromagnéticas podem causar ao interagir com os átomos do meio com os quais interagem. A energia das radiações depositada em um ponto é chamada de dose absorvida. A dosimetria é um estudo que visa quantificar os valores de dose depositados pelas radiações, essa quantificação é de grande necessidade em aplicações médicas como a radioterapia. Neste trabalho se estudou a possiblidade de uso do transistor bipolar de junção BC856 na dosimetria de feixes elétrons, que é um tipo de radiação muito empregado em radioterapia para o tratamento de tumores superficiais. O transistor bipolar de junção é um dispositivo eletrônico com função de amplificador de corrente em circuitos elétricos; essa característica é conhecida como ganho de corrente. Alguns estudos já mostraram que esses dispositivos tem sua capacidade de amplificar corrente diminuída quando são expostos a radiações, devido a danos causados em suas estruturas. Como os transistores estudados apresentam pequenas variações no ganho de corrente entre eles, mesmo quando de um mesmo lote, foram selecionados para este trabalho apenas aqueles com ganho semelhante. Os transistores foram irradiados com feixes de elétrons gerados por um acelerador linear Clinac iX da Varian, empregando feixes com energia de 6, 9 e 12 MeV. Os valores de corrente de coletor dos transistores eram medidos antes e imediatamente após as irradiações com o auxílio de um eletrômetro, de modo a avaliar a redução no ganho de corrente dos transistores. Foi possível observar uma relação linear entre a dose e o dano causado aos transistores pela radiação. Apesar de não se recuperarem completamente dos danos causados pela radiação, os dispositivos se mostraram reutilizáveis. Nas avaliações de percentual de dose depositada pelos feixes de elétrons em diferentes profundidades de acrílico, foi possível observar uma tendência de resultados obtidos com os transistores semelhante aos dados de calibração do acelerador linear utilizado para produção dos feixes. É possível concluir dos estudos que esses transistores podem ser usados em dosimetria de feixes de elétrons de megavoltagem devido à possibilidade de relacionar o dano causado pela radiação nos dispositivos com a dose absorvida.

Polímeros de coordenação têm atraído a atenção de pesquisadores na última década por conta de sua incrível versatilidade e virtualmente infinito número de possibilidades de combinação de ligantes orgânicos e centros metálicos. Estes compostos normalmente herdam as características magnéticas, eletrônicas e espectroscópicas de seus componentes base. Entretanto, apesar do crescente número de trabalhos na área, ainda são raros os polímeros de coordenação que apresentem condutividade elétrica. Para este fim, utilizou-se a N,N\'-bis(4-piridil)-1,4,5,8-naftaleno diimida, ou NDI-py, que pertence a uma classe de compostos rígidos, planares, quimicamente e termicamente estáveis e que já foram extensamente estudados por suas propriedades fotoeletroquímicas e semicondução do tipo n. O primeiro polímero de coordenação sintetizado, MOF-CoNDI-py-1, indicou ser um polímero linear, de estrutura 1D. O segundo, MOF-CoNDI-py-2, que conta com ácido tereftálico como ligante suporte, é um sólido cristalino com cela unitária monoclínica pertencente ao grupo espacial C2/c, determinado por difração de raios-X de monocristal. A rede apresenta um arranjo trinuclear de íons Co(II) alto spin com coordenados em uma geometria de octaedro distorcido, enquanto os ligantes NDI-py se encontram em um arranjo paralelo na estrutura, em distâncias apropriadas para transferência eletrônica. Com o auxílio de cálculo teóricos a nível de DFT, foi realizado um estudo aprofundado dos espectros eletrônicos e vibracionais, com atribuição das transições observadas, tanto para o MOF-CoNDI-py-2 quanto para o ligante NDI-py livre. A rede de coordenação absorve em toda a região do espectro eletrônico analisada, de 200 nm a 2500 nm, além de apresentar luminescência com característica do ligante. Dispositivos eletrônicos fabricados com um cristal do MOF-CoNDI-py-2 revelaram condutividades da ordem de 7,9 10-3 S cm -1, a maior já observada para um MOF. Além de elevada, a condutividade elétrica dos cristais demonstrou-se altamente anisotrópica, sendo significativamente menos condutor em algumas direções. Os perfis de corrente versus voltagem foram analisados em termos de mecanismos de condutividade, sendo melhores descritos por um mecanismo limitado pelo eletrodo to tipo Space-Charge Limited Current, concordando com a proposta de condutividade através dos planos de NDI-py na rede. A condutividade dos cristais também é fortemente dependente de luz, apresentando fotocondução quando irradiado por um laser vermelho, de 632 nm, enquanto apresenta um comportamento fotorresistivo frente a uma fonte de luz branca. Estes resultados, combinados, trazem um MOF em uma estrutura incomum e com elevada condutividade elétrica, modulada por luz, em medidas diretas de corrente. Não existem exemplos conhecidos de MOFs na literatura com estas características. / Coordination polymers have been a major topic in materials science during the past decade, thanks to their versatility and virtually infinite possible combinations between metal centers and organic ligands. These coordination polymers usually inherit the properties of their components, such as magnetic, spectroscopic and electronic characteristics. However, despite the increasing number of research papers in this topic, it is still hard to find coordination polymers featuring electronic conductivity. To achieve that, we used a naphthalene diimide derivative, N,N\'-bis(4-pyridyl)-1,4,5,8- naphthalene diimide or NDI-py, which belongs to a class of rigid, planar, thermally and chemically stable compounds, extensively studied due to their photoelectrochemical properties and their n-type semiconductivity. The first coordination polymer synthesised, MOF-CoNDI-py-1, was an amorphous linear polymer, with a 1D structure. Based on these observations, MOF-CoNDI-py-2 was synthesised by using terephthalic acid as a supporting ligand, and it is a crystalline solid which its monoclinic unit cell belongs to a C2/c space group, as determined by single crystal X-ray diffraction. This network features a trinuclear high-spin Co(II) unit, and each metal ion sits on a distorted octahedra coordination geometry, while the NDI-py ligands sit in a parallel arrangement, with distances suitable for electronic transfers. A detailed study of their vibrational and electronic spectra, supported by DFT calculations, was performed, as well as a full description and assignment of the observed bands. MOF-CoNDI-py-2 absorbs in the whole studied spectral region, from 200 nm to 2500 nm, while it also features a ligand-centered emission spectrum. Electronic devices built around its crystals revealed electric conductivities of 7.9 10 -3 S cm -1, which is, to the best of our knowledge, the highest for a MOF to this date. This conductivity is also highly anisotropic, being significantly less conductive in certain directions. The current versus voltage profiles were analysed in terms of known conduction mechanisms, with best fits when using an electrode-limited Space-Charge Limited Current mechanism, in agreement with the proposition that this conductivity happens through the NDI-py stacking planes. Additionally, this mechanism is influenced by an external light source, being a photoconductor with a red laser, 632 nm, and a photoresistor with a white light. Combined, these results bring a light-modulated, highly conductive MOF material with an unusual structure. As far as we know, there are no similar MOFs in the literature, which makes MOF-CoNDI-py-2 one of a kind.

Solar energy is an abundant renewable source, which is expected to play an increasing role in the grid's future infrastructure for distributed generation. The research described in the thesis focuses on the analysis of integrating multi-megawatt photovoltaics (PV) systems with battery energy storage into the existing grid and on the theory supporting the electrical operation of components and systems. The PV system is divided into several sections, each having its own DC-DC converter for maximum power point tracking and a two-level grid connected inverter with different control strategies. The functions of the battery are explored by connecting it to the system in order to prevent possible voltage fluctuations and as a buffer storage in order to eliminate the power mismatch between PV array generation and load demand. Computer models of the system are developed and implemented using the PSCADTM/EMTDCTM software.