Tesis sobre el tema "Solar processes"
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Hassan, Ibrahim. "Solar energy conversion by photoelectrochemical processes". Thesis, University of Bath, 2011. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.542078.
Texto completoStüwe, David [Verfasser] y Jan G. [Akademischer Betreuer] Korvink. "Inkjet processes for crystalline silicon solar cells". Freiburg : Universität, 2015. http://d-nb.info/1122646984/34.
Texto completoKohn, Alexander Wolfe. "Modeling non-radiative processes in solar materials". Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/115806.
Texto completoCataloged from PDF version of thesis.
Includes bibliographical references (pages 89-102).
In this thesis, we investigate methods and systems for understanding the electronic properties of a variety of systems relevant to organic photovoltaics. The second chapter examines how to predict the radiative and non-radiative decay rates of a large family of naphthalene derivatives. Naphthalene is a common building block in many organic electronic devices and possesses complex photophysics that are difficult to capture. Principally using time-dependent density functional theory, we are able to reproduce the experimental rates and, moreover, the fluorescence quantum yield, quite accurately. The next chapter then goes into extensions of the methodology discussed and analyzed in the prior chapter. Anthracene derivatives used for transferring triplet energy between a quantum dot and rubrene phase are found to have varying impacts on the total transfer efficiency based on the triplet lifetime of the anthracene derivative. Most potently, significant spin-orbit coupling in some of the derivatives causes substantial deactivation. An additional family, BODIPY dyes, is also investigated. They are found to undergo internal conversion gated by an excited-state conformational change, suggesting this may be a common motif. The fourth and fifth chapters investigate different interfacial effects and their impacts on the energy levels of electrons and holes in disordered organic devices. They look at specific systems: the interface between three different donors, PPV, P3HT, PTB7, and PCBM. They find that the interface can both reduce and induce disorder in different systems and that full treatment of the electronic environment is important for capturing accurate results. The final chapter investigates the use of neural networks to predict optimal range-separation parameters for density functionals.
by Alexander Wolfe Kohn.
Ph. D.
Singletary, Steven J. (Steven James) 1973. "Igneous processes of the early solar system". Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/58444.
Texto completoIncludes bibliographical references.
Experimental, petrographic and numerical methods are used to explore the igneous evolution of the early solar system. Chapters 1 and 2 detail the results of petrographic and experimental studies of a suite of primitive achondritic meteorites, the ureilites. The first chapter presents data that reveal correlations between mineral modal proportions and mineral chemistry that are used to guide experiments and models of ureilite petrogenesis. Chapter 2 details and applies the experimental results to describe ureilite petrogenesis as the result of progressive heating of a primitive carbon-rich body. The experiments place temperature and depth constraints on uteilite formation of 1100 to 13000C and 5 to 13 MPa - equivalent to the central pressure of an asteroid with a radius of 130 km. Chapter 3 reports the results of melting experiments of Allende carbonaceous chondrite at temperatures and pressures that would be expected on small bodies in the early solar system (up to 1300⁰C and 2.5 to 15 IPa) heated by decay of short lived isotopes. The results are then applied to ureilite petrogenesis and assembly of larger planetary bodies. The final chapter is an experimental study to test a hybridized source region for the high titanium lunar ultramafic glasses. Two models are presented that invoke either a heterogeneous source region or sinking and reaction of an ultramafic, titanium rich magma with underlying mantle regions.
by Steven J. Singletary.
Ph.D.in Geochemistry
DELL'ORTO, ELISA CAMILLA. "Dye sensitized solar cells: materials and processes". Doctoral thesis, Università degli Studi di Milano-Bicocca, 2012. http://hdl.handle.net/10281/28476.
Texto completoWilles, Andrew James. "Coherent wave processes in solar and interplanetary plasmas". Thesis, The University of Sydney, 1996. https://hdl.handle.net/2123/27549.
Texto completoSteinfeld, Jeffrey I. "High-flux solar photon processes: opportunities for applications". MIT Energy Lab, 1992. http://hdl.handle.net/1721.1/27220.
Texto completoJiménez, López Jesús. "Analysis of the Different Kinetic Processes in Perovskite Solar Cells". Doctoral thesis, Universitat Rovira i Virgili, 2019. http://hdl.handle.net/10803/668405.
Texto completoLa energía fotovoltaica se ha convertido en una de las alternativas más populares como fuente de energía renovable. Se basa en la transformación directa de radiación solar en electricidad. Se encuentra disponible a escala global y además no precisa de ningún transformador para convertir la energía mecánica en energía eléctrica, lo que hace que sea fácil de implementar. Hoy en día, el material más utilizado para aplicaciones fotovoltaicas sigue siendo el silicio. En cambio, el desarrollo de nuevas tecnologías, más baratas, fáciles de procesar y que además pueden utilizarse en sustratos flexibles, ha surgido como alternativa al silicio. De todas ellas, las perovskitas basadas en haluros de plomo se han convertido en una de las mejores opciones para la comunidad científica debido a las excelentes propiedades fotovoltaicas que presenta. Aunque las eficiencias de los dispositivos preparados con perovskitas han alcanzado el 25%, un valor que se encuentra muy cercano a su máximo teórico, los procesos que tienen lugar en estos dispositivos aún no son del todo conocidos. En esta tesis se trata de obtener información acerca de los procesos de los transportadores de carga, desde cómo se generan hasta la recombinación, tanto en las interfaces como en el interior del propio material. Para ello, se han utilizado distintas técnicas de caracterización avanzadas como el fotovoltaje transitorio (TPV), fotocorriente transitoria (TPC), la extracción de carga (CE) y la espectrocopía de absorción transitoria en la escala del femtosegundo (fsTA), obteniendo importantes conclusiones sobre pérdidas
Photovoltaics have become one of the most popular renewable source of energy. Photovoltaic technologies transform sunlight into electricity, and they are also available worldwide, and they do not depend on the conversion of motive power, making this technology quite easy to implement. Nowadays, silicon is still the most used material for photovoltaics. Anyway, new photovoltaic technologies have emerged as alternatives to silicon, as they are cheaper, easier to process, and, they are possible to use on flexible substrates. Among them, lead halide perovskites have become one of the most popular choice in the scientific community, due to the great properties that this material presents. While efficiencies have risen above 25%, which is close to their maximum theoretical limit, there is still debate about the processes happening in the device. In this thesis, we try to gain insight into charge carrier processes from their generation to their recombination at both perovskite interfaces, and also in the bulk of the material. Using advanced characterization techniques, such as transient photovoltage (TPV), transient photocurrent (TPC), charge extraction (CE), and femtosecond transient absorption spectroscopy (fsTA) we obtained important findings about charge carrier losses, and artifacts affecting charge carrier recombination in functional devices that lead to lower power conversion efficiencies.
Fitó, de la Cruz Jaume. "Solar-driven hybrid refrigeration systems based on thermochemical processes". Doctoral thesis, Universitat Rovira i Virgili, 2017. http://hdl.handle.net/10803/461061.
Texto completoEsta tesis doctoral propone dos sistemas híbridos de refrigeración basados en energía solar donde el elemento común es un proceso termoquímico: un sistema híbrido absorción / termoquímico activado con energía solar térmica de baja temperatura (< 120 ºC), y un sistema híbrido compresión / termoquímico activado con energía solar fotovoltaica y calor residual. El sistema absorción / termoquímico es presentado en su configuración más simple y sus componentes y condiciones de operación discutidas. El desempeño del ciclo es estimado preliminarmente con algunos pares de trabajo con amoníaco, con NH3/NaSCN y NH3/BaCl2 como pares interesantes. La simulación preliminar del sistema híbrido muestra que este aumenta la fracción solar. El sistema compresión / termoquímico es definido y simulado en la fase de acumulación de refrigerante asistida con compresión. Un modelo de reacción cuasi-estacionario de doble frente, que tiene en cuenta limitaciones de transferencia de masa y de calor, es usado para estudiar preliminarmente la influencia de algunas condiciones de operación y parámetros de diseño sobre la curva de reacción con el par amoníaco / cloruro de bario. Se ha construido un dispositivo experimental para obtener datos experimentales de la fase de acumulación de refrigerante asistida con compresor, y confrontar estos datos con las predicciones obtenidas del modelo de reacción de doble frente, con el objetivo de ajustar algunos parámetros del modelo. Se concluye que el modelo ajustado predice la curva de reacción con exactitud aceptable para casi todos los experimentos, con pequeñas discrepancias. Se espera que los sistemas híbridos propuestos operen con energía solar, sean relativamente compactos, almacenen energía en menor volumen, y tengan un pequeño grado de autonomía (unas pocas horas en un ciclo de operación diario). Estos sistemas son interesantes para futuros estudios.
This doctoral thesis proposes two solar-based hybrid refrigeration systems where the central piece is a thermochemical process: an absorption / thermochemical hybrid system driven by low-grade solar thermal energy (< 120 ºC), and a compression / thermochemical hybrid refrigeration system driven by solar-PV energy and waste heat. The absorption / thermochemical hybrid system is presented in its most simple configuration, and its components and operating conditions discussed. A preliminary performance estimation is carried out with some ammonia-based working pairs finding the NH3/NaSCN and NH3/BaCl2 as interesting working pairs. A preliminary simulation of the hybrid system shows that it increases the solar coverage. The compression / thermochemical hybrid system is also defined and simulated in its refrigerant storage phase assisted with compression. A 2-front quasi-steady reaction model which accounts for heat and mass transfer limitations is used to preliminarily study the influence of some operating conditions and design parameters on the system’s reaction curve with the NH3/BaCl2 working pair. An experimental setup has been built to obtain experimental data from the compression-assisted refrigerant storage phase, and confront this data with the predictions obtained from the 2-front reaction model, with the objective of adjusting some parametres of the model. It is concluded that the adjusted model predicts the reaction curve with acceptable accuracy for almost all experiments, with small discrepancies. The proposed hybrid systems are expected to operate with solar energy, be relatively compact, store energy with reduced storage volume, and have a small degree of autonomy (a few hours within a daily operating cycle). These systems are promising for further study.
Vocks, Christian. "Electron kinetic processes in the solar corona and wind". Thesis, Universität Potsdam, 2012. http://opus.kobv.de/ubp/volltexte/2013/6525/.
Texto completoDie Sonne ist von einer 10^6 K heißen Atmosphäre, der Korona, umgeben. Sie ist ebenso wie der Sonnenwind vollständig ionisiert, also ein Plasma. Magnetfelder spielen in einem Plasma eine wichtige Rolle, da sie elektrisch geladene Teilchen an ihre Feldlinien binden. EUV-Spektroskope, wie SUMER auf der Raumsonde SOHO, zeigen eine bevorzugte Heizung koronaler Ionen sowie starke Temperaturanisotropien. Geschwindigkeitsverteilung von Elektronen können im Sonnenwind direkt gemessen werden, z.B. mit dem 3DPlasma Instrument auf dem Satelliten WIND. Sie weisen einen thermischen Kern, einen isotropen suprathermischen Halo, sowie einen anti-solaren, magnetfeldparallelen Strahl auf. Zum Verständnis der physikalischen Prozesse in der Korona wird eine geeignete Beschreibung des Plasms benötigt. Die Magnetohydrodynamik (MHD) betrachtet das Plasma einfach als elektrisch leitfähige Flüssigkeit. Mehrflüssigkeitsmodelle behandeln z.B. Protonen und Elektronen als getrennte Fluide. Damit lassen sich viele makroskopische Vorgänge beschreiben. Fluidmodelle basieren aber auf der Annahme eines Plasmas nahe am thermodynamischen Gleichgewicht. Doch die Korona ist weit davon entfernt. Ferner ist es mit Fluidmodellen nicht möglich, Prozesse wie die Wechselwirkung mit elektromagnetischen Wellen mikroskopisch zu beschreiben. Kinetische Modelle, die Geschwindigkeitsverteilungen beschreiben, haben diese Einschränkungen nicht und sind deshalb geeignet, die oben genannten Messungen zu erklären. Bei den einfachsten Modellen bündelt die Spiegelkraft im interplanetaren Magnetfeld die Elektronen des Sonnenwinds in einen extrem engen Strahl, im Widerspruch zur Beobachtung. Daher muss es einen Streuprozess geben, der dem entgegenwirkt. In der vorliegenden Arbeit wird ein kinetisches Modell für Elektronen in der Korona und im Sonnenwind präsentiert, bei dem die Elektronen durch resonante Wechselwirkung mit Whistler-Wellen gestreut werden. Das kinetische Modell reproduziert die beobachteten Bestandteile von Elektronenverteilungen im Sonnenwind, d.h. Kern, Halo und einen Strahl endlicher Breite. Doch es ist nicht nur auf die ruhige Sonne anwendbar. Die Ausbreitung energetischer Elektronen eines solaren Flares wird untersucht und dabei festgestellt, dass Streuung in Ausbreitungsrichtung und Diffusion in Energie die Ankunftszeiten von Flare-Elektronen bei der Erde in etwa gleichem Maße beeinflussen. Die Wechselwirkung von Elektronen mit Whistlern führt in der Korona nicht nur zu Streuung, sondern auch zur Erzeugung eines suprathermischen Halos, wie er im interplanetaren Raum gemessen wird. Dieser Effekt wird sowohl im Sonnenwind als auch in einem geschlossenen koronalen Magnetfeldbogen untersucht. Das Ergebnis ist von fundamentaler Bedeutung für solar-stellare Beziehungen. Die ruhige Korona erzeugt stets suprathermische Elektronen. Dieser Prozeß ist eng mit der Koronaheizung verbunden, und daher in jeder heißen stellaren Korona zu erwarten. Im zweiten Teil der Arbeit wird beschrieben, wie sich aus der Geschwindigkeitsverteilung der Elektronen die Dämpfung oder Anregung von Plasmawellen berechnen lässt. Die Erzeugung und Ausbreitung von Elektronenzyklotronwellen in der ruhigen Korona und von Whistlern während solarer Flares wird untersucht. Letztere sind als sogenannte fiber bursts in dynamischen Radiospektren beobachtbar, und die Ergebnisse stimmen gut mit beobachteten Bursts überein.
ORLANDI, Michele. "PHOTOINDUCED PROCESSES IN SUPRAMOLECULAR SYSTRMS FOR SOLAR ENERGY CONVERSION". Doctoral thesis, Università degli studi di Ferrara, 2010. http://hdl.handle.net/11392/2389170.
Texto completoAl-Hasnawi, Hassan. "Solar Heat in Industrial Processes : Integration of Parabolic Trough Solar Collectors Dairy Plants and Pharmaceutical Plants". Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-125025.
Texto completoShapiro, Alexander I. "Molecular processes and turbulent magnetic fields in the solar atmosphere /". Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17961.
Texto completoFredin, Kristofer. "Studies of Charge Transport Processes in Dye-sensitized Solar Cells". Doctoral thesis, KTH, Kemi, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4430.
Texto completoQC 20100708
Fredin, Kristoffer. "Studies of charge transport processes in dye-sensitized solar cells /". Stockholm : KTH Chemical Science and Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4430.
Texto completoXu, He. "Laboratory studies on dynamical processes in salinity-gradient solar pond /". The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487677267731063.
Texto completoLisco, Fabiana. "High rate deposition processes for thin film CdTe solar cells". Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/17965.
Texto completoBrienza, Monica. "Solar Advanced Oxidation Processes for removing emerging contaminants in wasterwater". Thesis, Perpignan, 2015. http://www.theses.fr/2015PERP0001.
Texto completoWastewater effluents are the major source of micropollutants in the environment. These recalcitrant compounds that can be escape from wastewater treatment plant (WWTP) are called emerging contaminants. It is necessary to improve the efficiency of wastewater treatment plants. In fact, Water Framework Directive required a “good chemical and biological status” of all water bodies until 2015. The major aim of the dissertation was to contribute to improve the evaluation of solar advanced oxidation processes, and more specifically heterogeneous and homogeneous photocatalysis, for removing emerging contaminants from wastewater effluents. In this objective, the efficiency of AOPS was not only evaluated with the degradation and/or mineralization rates of the micropollutants. This necessary criterion was completed with the identification of the by-products and the associated transformation pathways, but also with toxicity measurements. This last point was explored with standard ecotoxicity tests and also estrogenic activity that represent a specific test relevant to characterize an identified risk associated to the discharge of effluents into the environment.All the experimental results obtained during this dissertation tends to demonstrate that solar advanced oxidation processes has the potential to open new feasible remediation strategies for WWTPs effluent tertiary treatment before wastewater reuse in irrigation for instance. All the tested molecules have systematically been degraded, high number of micro-organic pollutants initially presented in a mixture were removed even at very low concentration, environmental compatibility is systematically improved
Ozgurel, Ozge. "Modeling the chemical trapping processes in the outer solar system". Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066226/document.
Texto completoThis project aims at answering some questions in planetology by means of ab-inito quantum chemistry. It can be divided into two main studies. One models the chemical processes likely to explain the noble gases deficiency observed by the Huygens probe in the atmosphere of Titan; it investigates the formation of stable complexes between Ar, Kr, Xe and H3+ or protonated ions by radiative association, in the proto-solar nebula, prior to the formation of Titan. The other analyzes the trapping mechanisms of volatiles in the ice at work in comets as well as in Europa. Scenarios of primordial origin for O2 and S2, observed in comet 67P/C-G by the ROSETTA probe, were thus validated, giving abundance ratios with H2O close to those observed and proposing an explanation for the respective correlation/non-correlation with water of the two species. Also, a scenario for the origin of trace elements Na, K detected in the exosphere of Europa whose interest is revived by anticipating the missions Juice and Europa Clipper, was argumented and found available for Mg and Ca to predict relative abundancies to be observed. The computational work combines two ab-inito approaches, molecular calculations in gaseous phase in the first case and periodic solid state calculations in the second
RAZZA, STEFANO. "Development of fabrication processes for large area perovskite solar cells". Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2014. http://hdl.handle.net/2108/202974.
Texto completoAl-Thani, Faleh N. "Economical desalination processes in Qatar". Thesis, University of Hertfordshire, 2002. http://hdl.handle.net/2299/14043.
Texto completoAl-Edhari, Ali Jaber. "Complex organic molecules in solar-type star forming regions". Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAY048/document.
Texto completoThe present PhD thesis goal is the study of the molecular complexity in solar type star forming regions. It specifically focuses on two classes of molecules with a pre-biotic value, the complex organic molecules and the cyanopolyynes.At this scope, I analyzed data from single-dish spectral surveys by means of non-LTE or/and non-LTE radiative transfer codes in two sources, a solar type protostar in an isolated and quiet environment (IRAS16293-2422) and a proto-cluster of solar type protostars (OMC2-FIR4). The goal is to find similarities and differences between these two cases.I used data from two spectra surveys: TIMASSS (The IRAS16293-2422 Millimeter And Submillimeter Spectral Survey), which has been carried out in 2011 (Caux et al. 2011), and ASAI (Astrochemical Surveys At IRAM), which has been carried out in 2013-2015 (e.g. Lopez-Sepulcre et al. 2015).I extracted the lines (identification and integrated intensity) by means of the publicly available package CASSIS (Centre dAnalyse Scientifique de Spectres Infrarouges et Submillimtriques).Finally, I used the package GRAPES (GRenoble Analysis of Protostellar Envelope Spectra) to model the Spectral Line Energy Distribution (SLED) of the detected molecules, and to estimate their abundance across the envelope and hot corino of IRAS16293-2422 and OMC2-FIR4, respectively.The major results of the thesis are:1) The first full census of complex organic molecules (COMs) in IRAS16293-2422;2) The first detection of COMs in the cold envelope of a solar type protostar (IRAS16293-2422), supporting the idea that a relatively efficient formation mechanism for the detected COMs must exist in the cold gas phase;3) The discovery of a tight correlation between the dimethyl ether (DME) and methyl format (MF), suggesting a mother-daughter relationship;4) The detection of formamide, a species with a very high pre-biotic value, in several protostars, included IRAS16293-2422 and OMC2-FIR4;5) The full census of the cyanopolyynes in IRAS16293-2422 and OMC2-FIR4, with the detection of HC3N and HC5N, DC3N and, for OMC2-FIR4, the 13C isotopologue of HC3N cyanopolyynes.These results are the focus of two published articles (Jaber et al. 2014, ApJ; Lopez-Sepulcre, Jaber et al. 2015, MNRAS), one accepted article (Jaber et al., A&A) and a final article to be submitted (Jaber et al., A&A)
De, Leuw Simone. "Manganese and chromium isotopes nebular processes and early solar system chronology /". Diss., Restricted to subscribing institutions, 2009. http://proquest.umi.com/pqdweb?did=1997764951&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Texto completoHantoosh, Mohammed y Mohammed Hantoosh. "Advanced Oxidation Processes of Trace Organics in Water by Solar Photolysis". Thesis, The University of Arizona, 2016. http://hdl.handle.net/10150/620873.
Texto completoHaeussler, Anita. "Solar fuels production by CO2 and H2O splitting via thermochemical processes". Thesis, Perpignan, 2021. https://theses-public.univ-perp.fr/2021PERP0003.pdf.
Texto completoThis study is focused on the development of thermochemical H2O and CO2 splitting processes using non-stoichiometric metal oxides and concentrated solar energy to produce solar fuels. The redox process is composed of two distinct reactions: first, a thermal reduction at high temperature of the metal oxide with creation of oxygen vacancies in the crystallographic structure, resulting in released oxygen; second, the re-oxidation of the metal oxide by H2O and/or CO2, leading to H2 and/or CO production. Ceria and perovskite materials have been investigated as reactive oxides for thermochemical cycles. To increase the thermochemical process efficiency, different aspects were investigated, such as chemical composition and morphology of the metal oxide, operating parameters, and solar reactor configuration. The redox activities, kinetics and thermodynamics of different perovskite materials were first experimentally investigated for two-step thermochemical cycles. Then, the thermochemical performances of various reactive materials shaped as porous structures or particulate media were investigated in solar reactors (monolithic or packed-bed configurations) able to perform two-step thermochemical cycles. A detailed parametric study was performed to determine fuel production rates and yields. The highest CO production rate (9.9 mL/min/g) was achieved with ceria reticulated foams. Finally, a solar membrane reactor was developed for isothermal and continuous production of CO (or H2) by CO2 (or H2O) splitting with a reactive and oxygen-permeable membrane. The highest CO production rate reached 0.133 µmol/cm2/s at 1550 °C using a perovskite-coated ceria membrane
Guo, Huairui. "Variation monitoring, diagnosis and control for complex solar cell manufacturing processes". Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280704.
Texto completoTang, Jian. "From Silicon to Germanium Nanowires : growth processes and solar cell structures". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLX014/document.
Texto completoThis thesis is dedicated to develop new solar cell architectures based on nanowires produced by a plasma-assisted Vapor Liquid Solid process. By optical modeling, detailed field and absorption profiles in the NW solar cells have been obtained and a 14 mA/cm2 matched photocurrent has been achieved for a-Si:H/µc-Si:H tandem solar cells. An electrical model for radial PN junction NW solar cells has also been developed from first principle rules, allowing a good understanding of the carrier transport. By analyzing step by step the SiNWs growth in a PECVD system we could propose a detailed explanation for the strong evolution of the NW density, morphology and crystallinity during growth. The rare hexagonal phase of Si has been observed in the as grown SiNWs with diameters smaller than 10 nm. For the first of time, we have provided TEM characterizations from [11-20] direction to give a clear proof of the hexagonal Si phase in as grown SiNWs. To develop low band bap, high mobility material for multi junction NW solar cells, we added germane to silane during the plasma-assisted VLS growth process. Ge contents from 0 to 100% have been achieved with Sn, In and Cu catalysts. We have found that above a critical temperature (~ 350 °C), micrometer long cylindrical Ge NWs can be obtained. NW based PIN radial junction solar cells having a-Si:H, a-SiGe:H and µc-Si:H as intrinsic absorber layers have been fabricated. For the SiGeNWs based solar cells, a 6% energy conversion efficiency has been achieved with p-i-n configuration. To our knowledge, this is the first demonstration of SiGeNWs based photovoltaic device
Clemens, A. J. "Pickup ion processes associated with spacecraft thrusters : implications for solar probe plus". Thesis, Queen Mary, University of London, 2016. http://qmro.qmul.ac.uk/xmlui/handle/123456789/18424.
Texto completoLayden, Andrew. "Mode Conversion Processes in Magnetized Plasmas". Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/10437.
Texto completoBras, Patrice. "Sputtering-based processes for thin film chalcogenide solar cells on steel substrates". Doctoral thesis, Uppsala universitet, Fasta tillståndets elektronik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-329778.
Texto completoHenning, Annette. "Ambiguous Artefacts : Solar Collectors in Swedish Contexts. On Processes of Cultural Modification". Doctoral thesis, Högskolan Dalarna, Miljöteknik, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:du-950.
Texto completoTheis, Karen Julia. "Iron isotope fractionation of planetary bodies during early solar system formation processes". Thesis, University of Manchester, 2008. http://www.manchester.ac.uk/escholar/uk-ac-man-scw:163898.
Texto completoKolodziej, Charles. "Laser Spectroscopic Studies of Ultrafast Charge Transfer Processes in Solar Cell Materials". Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1586371698913592.
Texto completoNissfolk, Jarl. "Charge Transport Processes in Mesoporous Photoelectrochemical Systems". Doctoral thesis, KTH, Organisk kemi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9849.
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Al-Achkar, Mohamed. "Efficiency enhancement and degradation processes in Cuâ†xS/CdS thin film solar cells". Thesis, University of Hull, 1990. http://hydra.hull.ac.uk/resources/hull:3703.
Texto completoKolotkov, Dmitrii. "Nonlinear and multi-modal oscillatory processes in active regions of the solar atmosphere". Thesis, University of Warwick, 2017. http://wrap.warwick.ac.uk/93215/.
Texto completoBashir, Muktar. "A novel approach for integrating concentrated solar energy with biomass thermochemical conversion processes". Thesis, Aston University, 2017. http://publications.aston.ac.uk/30868/.
Texto completoSchmich, Evelyn Karin. "High-temperature CVD processes for crystalline silicon thin-film and wafer solar cells". München Verl. Dr. Hut, 2008. http://d-nb.info/992162874/04.
Texto completoDeng, Zhuo y 鄧卓. "Luminescence and transport processes of charge carriers in the GaxIn₁-xP/GaAs double-junction tandem solar cells". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/211134.
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Physics
Doctoral
Doctor of Philosophy
Hudson, Stephen R. "Solar radiation processes on the East Antarctic Plateau : interaction of clouds, snow, and atmospheric gases /". Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/10066.
Texto completoPotter, Stephen Edward. "Modelling of three-dimensional transient conjugate convection-conduction-radiation heat transfer processes and turbulence in building spaces". Thesis, Northumbria University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245440.
Texto completoNeuschitzer, Markus. "Development of Cu2ZnSnSe4 Based Thin Film Solar Cells by PVD and Chemical Based Processes". Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/400489.
Texto completoLos compuestos Cu2ZnSnSe4 (CZTSe), Cu2ZnSnS4 (CZTS) y Cu2ZnSnSexS4-x (CZTSSe) también conocidos como kesteritas debido a su estructura, presentan propiedades prometedoras para sustituir a la tecnología de células solares de capa fina basadas en Cu(In,Ga)Se2, evitando el problema potencial que podría generar el uso de indio y galio. A día de hoy, las eficiencias obtenidas en dispositivos de CIGS, son bastante mayores que las reportadas para dispositivos de kesteritas, debido entre otras razones a la diferencia en la madurez de dicha tecnología. Por lo tanto, es necesario un estudio más profundo de los materiales y dispositivos basados en kesteritas, enfocado a aumentar los valores de eficiencia de los dispositivos. El objetivo principal de esta Tesis Doctoral es el desarrollo y optimización de células solares con capas absorbentes basadas en el compuesto CZTSe por métodos de bajo coste incluyendo procesos de deposición física en fase vapor, así como también por procesos químicos. Se ha prestado especial interés en aumentar el conocimiento sobre la influencia de las propiedades de la superficie de la capa absorbente en el funcionamiento de las células solares. Estos estudios incluyen la optimización de la capa de kesterita, y también de su interfaz con la capa “buffer” o semiconductor tipo n en la heterounión. Se incluye un estudio detallado de la influencia de las propiedades químicas de la superficie del absorbente en la eficiencia de los dispositivos. Además, se presentan los estudios de optimización de la capa buffer basada en CdS y de capas buffer libres de Cd, usando como alternativa ZnS(O,OH), donde se obtuvieron eficiencias comparables con las de los dispositivos de referencia fabricados con CdS. Finalmente, se presenta un estudio de recristalización asistida por una capa nanométrica de Ge depositada en los precursores nano cristalinos. Se demuestra que este proceso induce un aumento significativo del crecimiento de los granos del absorbedor, reduciendo la presencia de defectos profundos eléctricamente activos que resultan perjudiciales para las propiedades de los dispositivos fotovoltaicos. Las mejoras presentadas en este estudio son altamente prometedoras y conducen hacia nuevas rutas de optimización en la fabricación de estos dispositivos.
Boghossian, Ardemis A. (Ardemis Anoush). "An engineering analysis of natural and biomimetic self-repair processes for solar energy harvesting". Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/76478.
Texto completoCataloged from PDF version of thesis.
Includes bibliographical references (p. 191-201).
Plants have evolved highly sophisticated mechanisms of self-repair to regenerate proteins that become photo-damaged over time. Key to this self-repair process is the reversible self-assembly of protein complexes, which is characterized by the molecular recognition of parts, kinetic trapping of meta-stable thermodynamic states, and chemical signaling to switch between states. In this thesis, we mimic such regenerative mechanisms in an effort to develop biological light-harvesting devices with prolonged lifetimes. We demonstrate the first synthetic photoelectrochemical cell capable of mimicking key aspects of the self-repair process. Surfactant addition and removal was used to signal between the disassembly and re-assembly of a photoactive complex demonstrating photo-conversion efficiencies of 40%. These dynamic complexes consist of lipid bilayer disks housing photoactive reaction centers (RCs) that align along the length of a single-walled carbon nanotube (SWNT). Application of a regeneration cycle that reversibly signals between the assembled and disassembled states extends the lifetime of the photoelectrochemical cell indefinitely and increases cell efficiency by over 300% over 168 hours. We modeled the kinetic and thermodynamic forces that drive the reversible self-assembly, and we fit this model to spectrofluorimetric measurements that monitor complex formation. The bestfit rate constants for lipid bilayer and bilayer-nanotube complex formation are 79 mM-Is'Iand 5.4x 10 mM-1 s- 1, respectively. We find that these reactions do not occur under diffusioncontrolled conditions, and the phase diagram predicts a locally optimal surfactant removal rate of 8 x 10-4 s-1. This model was subsequently fit to cyclic complex assembly and disassembly measurements, demonstrating that the forces modeled in this study may form the basis for synthetic and natural photoactive complexes capable of dynamic component repair. In an effort to extend our scope to study natural regeneration mechanisms, we established a platform for quantifying reactive oxygen species (ROS) generation in isolated chloroplasts capable of autonomous regeneration. ROS generation from illuminated chloroplasts from S. oleracea was examined in the presence of dextran-wrapped nanoceria (dNC), cerium ions (Ce3 ), fullerenol, and DNA-wrapped SWNTs. ROS concentrations were evaluated using the oxidative dyes, 2',7'- dichlorodihydrofluorescein diacetate (H2DCF-DA) and 2,3-bis(2-methoxy-4-nitro-5- sulfophenyl)-2H-tetrazolium-5-carboxanilide sodium salt (XTT). Chloroplast photoactivity was monitored throughout the illumination period using chloroplast fluorescence and the artificial, photosynthetic electron accepting dye, dichloroindophenol (DCPIP). The results of this study indicate that dNC offers a promising mechanism for effective ROS scavenging whilst preserving chloroplast photoactivity at concentrations below 5 [tM. We have also established several platforms for studying the glucose production of isolated chloroplasts for biofuel cell applications. We developed an algorithm to quantify single-molecule efflux measurements from individual, photoactive chloroplasts. Near-infrared fluorescing SWNTs have been used in previous studies to report single-molecule binding events via stochastic fluctuations in fluorescence. In this thesis, we develop and compare several algorithms for extracting concentration-dependent rates from the stochastic fluctuations. Overall, the birthand- death model most accurately predicts the rate constants, whereas the moment analysis is more accurate at large forward rates (>10-3 s-1). Glucose efflux from chloroplasts was characterized using a glucose oxidase assay, high-pressure liquid chromatography (HPLC), and a biofuel cell. Calculated export rates of 1.9 and 6 tmol/(mg chlorophyll hr) were measured using the HPLC and fuel cell, respectively. Maximum power densities of 110 pW/cm 2 were achieved with alginate encapsulated chloroplasts. In the presence of regenerative materials, such as dNC, this biofuel cell setup provides a promising platform for demonstrating a biological lightharvesting construct capable of autonomous regeneration
by Ardemis A. Boghossian.
Ph.D.
Barulina, Elena. "Study of the photostability of organic solar cells : impact of materials and encapsulation processes". Electronic Thesis or Diss., Aix-Marseille, 2020. http://theses.univ-amu.fr.lama.univ-amu.fr/201209_BARULINA_247fcnnrd470uh345hs973z_TH%20(1).pdf.
Texto completoDespite a strong increase in the electrical conversion efficiencies of organic solar cells, their long-term stability is a key factor for their commercial viability and therefore needs to be examined in detail. The objective here was to study the lifetime of organic solar cells by varying the active materials in the D:A mixture, the cell architecture, the interfacial layers, the treatments applied and the encapsulation process. Regardless of these parameters, a high stability could be obtained for PC71BM-based devices under LED. On the other hand, under AM1.5, a post-annealing process considerably improves the stability of the devices, but the choice of the cell structure remains the key parameter where only cells with normal structure showed a high stability over time. These layers were studied by absorption spectroscopy, AFM, XRD and analytical TEM. PC71BM-based devices can thus serve as a reference in the study of the stability of mixtures based on NFAs (PBDB-T:ITIC and PBDB-T-2F:ITIC-4F). Regardless of the illumination (LED or AM1.5) and the various parameters, NFA-based solar cells are unstable. Under LEDs, ITIC-4F-based solar cells have a better stability than ITIC-based solar cells, but this degradation also depends very strongly on the chemical nature of the electron extraction layer. Flexible encapsulation processes on ink-jet-printed modules from Dracula Technologies have been evaluated. These modules demonstrated relatively stable properties after 1000 hours of continuous illumination by a non-UV-filtered xenon lamp
Merino, Jose Carlos Alvarez y Kazuo Hatakeyama. "Technology surveillance of the solar refrigeration by absorption/adsorption". Institute of Electrical and Electronics Engineers Inc, 2016. http://hdl.handle.net/10757/622310.
Texto completoIn order to establish networks of cooperation looking for not to duplicate research and even to make use of existing research in a remote form, it is necessary to identify and classify (around the world) the researchers and laboratories, that are researching in the topic of solar refrigeration by absorption/adsorption. The methodology consists in: i) the technology's classification, ii) technological trajectory Identification, iii) a thematic bibliographic review, and iv) patent's analysis. In this way, with the previous determination of keywords, will be identified main authors and their respective institutions. With the same keywords, are determined the licensed patents (in certain span of time). In addition, the analysis of publications, patents, and commercial products give us an opportunity to establish comparisons between prototypes and tests (in several conditions). The larger results implicate the use of actor's network and the remote access to the data and tests, for a collaborative research, overcoming the lack of laboratory resource and accelerating the knowledge acquisition
Revisión por pares
Vocks, Christian [Verfasser] y Klaus G. [Akademischer Betreuer] Strassmeier. "Electron kinetic processes in the solar corona and wind / Christian Vocks. Betreuer: Klaus G. Strassmeier". Potsdam : Universitätsbibliothek der Universität Potsdam, 2013. http://d-nb.info/1035307405/34.
Texto completoYang, Wenxing. "Exploring Electronic Processes at the Mesoporous TiO2/Dye/Electrolyte Interface". Doctoral thesis, Uppsala universitet, Fysikalisk kemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-310191.
Texto completoTakasao, Shinsuke. "Fundamental Magnetohydrodynamic Processes of Solar Flares: Formation of Flare-productive Regions and Evolution of Flare Loops". 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215316.
Texto completoJenkins, Judith Lynn. "Spectroscopic and Spectroelectrochemical Characterization of Fundamental Interfacial Charge Transfer Processes Relevant to Efficient Solar Energy Conversion". Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/255173.
Texto completoCavallari, Marco Roberto. "Desenvolvimento de uma metodologia de fabricação de transistores de filmes finos orgânicos". Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-03112010-120818/.
Texto completoIn this work, it is presented a methodology for organic thin-film transistor (OTFT) fabrication. Poly(3-hexylthyophene) (P3HT):[6,6]-phenyl-C61-butyric acidmethyl ester (PCBM) bulk heterojunction solar cells were studied for their maximum power conversion efficiency (PCE) around 5 %. Efficiencies evolution in time from 10-6 to 1.7 % show the difficulties involved in organic thin-film processing and device characterization. It is of remarkable importance the electrodes geometry, the organic blend solution preparation and the extra-care while processing on flexible substrates (e.g. polyethylene terephthalate PET). Devices are composed of indium tin oxide covered glass, poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonic acid) (PEDOT:PSS), P3HT:PCBM active layer, lithium fluoride (LiF) and aluminum. PET covered with In2O3/Au/Ag substituting glass-ITO was employed due to the electronic industry research for low cost alternative materials. Similar structure is used for charge carrier mobility characterization. Techniques such as Time of Flight (ToF), Charge Extraction in Linearly Increasing Voltage (CELIV), and charge transport modeling of current density vs. voltage (JxV) stationary curves were applied on semiconductors like poly(para-phenylene vinylene) (PPV) derivatives. Mobilities around 10-810-6 cm2/Vs for space charge limited current (SCLC) with shallow and deep traps were obtained. Field effect mobilities characterized in bottom gate bottom contact TFTs with common gate are at least two orders higher than previous values. During this work, it was tested different substrates (e.g. monocrystalline silicon and glass-ITO), insulators (e.g. PECVD silicon oxynitride and thermal SiO2), surface treatments (e.g. hexamethyldisilazane vapor), semiconductors (PPV derivatives, P3HT, pentacene) and electrodes (e.g. titanium adhesion layer). It was defined that way a methodology of new semiconducting material selection for the electronic industry.