Tesis sobre el tema "Dépôt de couches atomiques (ALD)"
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Létiche, Manon. "Élaboration de matériaux pour microbatterie 3D Li-ion par dépôt de couches atomiques (ALD) et caractérisations structurales operando". Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10183/document.
Texto completoIn order to address the demand on energetic needs to sustain nomad and miniaturized electronic devices, micro-devices performance for energy storage such as Li-ion microbatteries (MB) have to be improved. An attractive way to meet the required performance consists in using 3D topology increasing the specific surface while keeping the initial surface footprint (in the mm2 range) which is significantly enhancing the delivered energy density of the MB. The development of thin film technologies such as ALD enabling conformal deposition makes it possible. In the framework of this thesis, a solid electrolyte (Li3PO4) has been developed and optimized by ALD, on a 3D micro-architectured silicon substrate obtained by microfabrication techniques. A positive electrode (LiMn1.5Ni0.5O4) has also been developed and optimized as a function of the deposition parameter by RF sputtering deposition on a Si/Al2O3/Pt substrate. A volumetric capacity of 63 µAh.cm-2.µm-1 has been measured for a film of 420 nm thick obtained at 0.01 mbar and then annealed at 700°C under air atmosphere. Finally, a prototype has been proposed to realize an electrochemical cell for the purpose of in situ/operando follow-up by XRD of a thin film electrode deposited on silicon substrate
Chen, Yuan. "Elaboration de films minces thermoélectriques par dépôt électrochimique en couches atomiques (EC-ALE)". Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4342.
Texto completoAn electrochemical atomic layer epitaxy (EC-ALE) experiment platform was designed and constructed in this thesis, and this platform was proved to be qualified for EC-ALE experiments.Benefiting from the flexibility of the EC-ALE equipment, a new viewpoint about the UPD behavior of cobalt on the gold substrate has been put forward in this work. The results also show that the subsequent alternate deposition of Co and Sb monolayers is feasible.For the first time the electrodeposition of Sb2Se3 thin films by EC-ALE method on polycrystalline Au electrodes has been obtained and investigated. The deposition parameters were determined and the deposit was characterized by SEM and Raman analysis.The irreversible adsorption and reversible UPD behaviour of Sb on Pt electrode have also been studied. The results show that after the irreversibly adsorbed SbO+ species are reduced to metallic Sb, Sb atoms can be further deposited onto this Sb-modified Pt electrode in the way of UPD to increase the coverage of Sb on the Pt substrate
Masse, de la Huerta César Arturo. "Développement de la technique dépôt par couche atomique spatiale (SALD) pour la fabrication de couches minces type P d'oxyde de cuivre (I) conductrices". Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAI067.
Texto completoTo successfully design the instrumentation needed for new manufacturing technologies with nanoscale precision, the design methodology must take into account many different topics related to chemistry, physics, mechanics, electronics and automation, working together to achieve the desired goal. In this thesis, this design methodology has been implemented with a large number of tools and approaches to successfully optimize a nanofabrication method called spatial atomic layer deposition (SALD) in order to deposit thin films. a potentially useful material as a component of non-silicon solar energy devices, photoelectrochemical water separators and transparent thin-film electronic components, among others: cuprous oxide (Cu2O).With respect to manufacturing technology and mechatronics design, SALD is a promising manufacturing technique that enables the fabrication of thin films with nanoscale precision and the ability to control their mechanical, electrical and crystallographic properties. In addition, the SALD approach used in this thesis and in the Laboratoire des Matèriaux et du Génie Physique(LMGP) works in the open air (without a repository) and is therefore potentially an industry-compatible approach to film Thin homogeneous high-area manufacturing with high throughput. In addition, SALD can be used under conditions that make it compatible with flexible substrates and roll-to-roll approaches (R2R). Finally, SALD offers flexibility on the deposit process so that it can be adjusted to obtain different properties on films manufactured with a minimum of instrumentation modification.Using CFD (Computational Fluid Dynamics) simulations, the fluid mechanics phenomena that occur during the deposition process in the SALD system were analyzed for different reactor configurations. The influence on the properties of the film was studied and a validation with experimental deposits was carried out. Then, using the knowledge and guidance obtained with CFD simulations, and to reduce the cost and complexity of modifying certain mechanical components of the system, a workflow that includes computer-aided design (CAD) and manufacturing additive (also called 3D printing) printing) was set up at the LMGP for the manufacture of one of the main components of the LMGP SALD system: the deposit head. Here, it is the first time that such an innovative manufacturing technique has been applied to thin-film nanofabrication processes, offering many potential applications in the field. In this thesis, such a workflow is presented and explained, along with learned guidelines and discovered limitations also presented.Finally, thin layers of Cu2O have been successfully deposited with the SALD method. Cu2O is one of the few materials with promising electronic properties as a p-type transparent semiconductor. Here, Cu2O films made using the LMGP SALD system are reported and their p-type conductivity and crystallography are analyzed.The results of this work provide initial guidance for the industrial design of a high throughput manufacturing system based on SALD technology optimized for each desired material. This design approach also makes this work useful for increasing the amount of SALD compatible materials, as well as for further developing the SALD methodology in innovative materials and device manufacturing processes
Pawlik, Matthieu. "Etude de la passivation de surface du silicium cristallin type P par dépôt de couches atomiques d'alumine pour application aux cellules solaires à haut rendement". Thesis, Ecole centrale de Lille, 2015. http://www.theses.fr/2015ECLI0008/document.
Texto completoThe decrease of solar cell cost as well as the increase in their efficiency are main research topics since the photovoltaic market crisis in 2011. One of the main strategy is to move towards thinner solar cells, in order to decrease raw material consumption. However, the result is a higher impact of surface phenomena on cell characteristics because of a high influence of structure and electronic defects at the surface. These defects can be passivated by Al2O3 coated by PE-ALD (Plasma Enhanced-Atomic Layer Deposition) which has been shown to provide the best surface passivation on p-type silicon. In an as-deposited state, the passivation level of Al2O3 is very low and required an annealing treatment to be "activated". This phenomenon provides an increase of the minority carrier effective lifetime. This thesis founded by the ANR PROTERRA and BIFASOL projects with the financial support of the Ecole Centrale de Lille, focuses on the optimization of the deposition parameters of alumina with a deeper insight on the passivation activation phenomena on samples with and without emitter. The passivation analysis has been performed thanks to coupled lifetime (QSS and micro PCD), surface potential (Kelvin probe), electrical (C-V) and chemical (SIMS, XPS) characterizations. The origin of the chemical and field effect passivation has been determined within the Si/SiO2/Al2O3 stack. The dynamics of the hydrogen contained in bulk alumina is explained. The impact of a SiNx capping layer and a contact alloying anneal at 830°c for 3s is also investigated
Fraccaroli, Mathias. "Synthèse par CVD/ALD sur grandes surfaces d'un sulfure de vanadium transparent et conducteur". Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALT006.
Texto completoIn the context of functional diversification (“More than Moore”), transition sulfides are currently being actively studied for original optical devices production. Some materials in this family have a lamellar structure, similar to graphene like vanadium sulfides. The synthesis of these lamellar films remains actively dominated by high-temperature CVD processes (> 550 ° C). However, in order to hope the development of a reliable synthesis methods, it's important to reduce this deposition temperature which leads to a poor uniformity and a poor conformity. In this work we have studied the potential of a chemical vapor deposition approach at low temperature (200 ° C). This method allow us to obtain an amorphous vanadium sulfide film on a 300 mm wafer and point out theirability to self-reorganize in order to obtain a lamellar film of V7S8 after thermal annealing. A 5.2nm film has interesting optical and electrical properties; this film is conductive with a carrier density of 1.1.1023 cm-3, the holes are the main charges carriers (type p), a mobility of 0.2 cm2. (Vs) -1, a conductivity of 1063 S.cm -1, an output work of 4.8 eV while preserving good transparency (transmittance of 75% for a wavelength of 550nm)
Garcia, Ramirez Emmanuel Armando. "Etude et optimisation de matériaux diélectriques et électrodes déposés par ALD pour structures nano-poreuses". Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMC226.
Texto completoThis research investigates the use of hafnium oxide (HfO2)-based thin films in nanocapacitors, focusing on both their linear and non-linear electrical properties to meet the growing demands of high-performance and miniaturized electronic devices. Starting with the fundamental physics of energy storage capacitors, the investigation highlights the essential characteristics of effective dielectric materials, such as a high dielectric constant and a substantial band gap. Hafnium-based materials are particularly promising due to their compatibility with Atomic Layer Deposition (ALD), which allows for precise and uniform thin-film deposition—crucial for ensuring reliable performance in electronic devices.To understand the potential of these materials, various fabrication and characterization techniques were employed. This includes specific deposition processes to create the thin films and morphological tests to study the physical structure of the capacitors. Electrical testing plays a key role in evaluating critical parameters like dielectric constant, breakdown voltage, and overall energy storage capacity. By analyzing these factors, a comprehensive view of how both linear and non-linear hafnium-based dielectrics perform is provided.When exploring linear, amorphous hafnium-based dielectrics, HfO2 is combined with aluminum oxide and silicon dioxide to enhance dielectric properties. Different configurations, such as nanolaminates and solid solutions, are tested to find the optimal balance. The goal is to achieve materials that maintain a high dielectric constant and resist voltage breakdown, thereby improving their ability to store energy efficiently. On the other hand, a detailed look into non-linear, crystalline dielectrics examines the effects of doping hafnium oxide with elements like zirconia and silicon. Different deposition and annealing temperatures are assessed for their impact on crystalline structure and polarization behavior, revealing complex ferroelectric and antiferroelectric behaviors that could offer high energy density and stability.The findings suggest that while ferroelectric materials might not be suitable for applications requiring linear capacitance due to their sensitivity to voltage variations, antiferroelectric materials show promise. However, they still face challenges related to electrical efficiency and thermal management. Finding materials that can effectively stabilize voltage variations is crucial, as capacitors are increasingly used to manage these fluctuations in modern electronics.A significant challenge identified is the variability in the dielectric constant, which can limit the use of these materials in applications demanding stable capacitance, such as signal filtering. To address this issue, solid solutions and laminated materials, which provide consistent linear capacitance, are prioritized. Although these materials are effective up to a certain permittivity threshold, exploring non-linear phases opens the door to potentially higher performance under specific conditions.In summary, understanding of HfO2-based thin films and their role in nanocapacitors is advanced by this research. By examining both linear and non-linear dielectric materials, insights into how to optimize fabrication techniques and material compositions to improve dielectric properties are provided. Ongoing research into issues like material endurance, electrical efficiency, and thermal management is essential for developing reliable and high-performing capacitors that meet the evolving demands of modern electronic technologies
Benamira, Messaoud. "Conducteurs mixtes nanostructurés pour les piles à combustible à oxyde solide (SOFC) : élaboration et performances de nouvelles architectures". Phd thesis, Paris 6, 2008. http://pastel.archives-ouvertes.fr/pastel-00004896.
Texto completoMantoux, Arnaud. "Synthèse par dépôt de couches atomiques et caractérisations de couches minces d'oxyde de vanadium applications aux accumulateurs au lithium". Paris 6, 2003. http://www.theses.fr/2003PA066206.
Texto completoBarbos, Corina. "Passivation de surface des cellules photovoltaïques en silicium cristallin : Dépôt par ALD et caractérisation de couches minces d’Al2O3". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI149/document.
Texto completoThe reduction of recombination at the surfaces of solar cells is a fundamental challenge for the photovoltaic industry. Passivation of surface electrical defects can be achieved by the formation of chemical bonds or by the supply of electric charges capable of repelling a type of carrier. These effects can be obtained by means of functionalized thin layers deposited on the surfaces of the materials which constitute the cells. In this thesis we studied the surface passivation of silicon by thin layers of Al2O3 deposited by ALD. The physical, optical, structural and chemical characterization of the deposited layers was carried out. An optimization of the preparation process (pre-deposition cleaning, deposition and annealing parameters) of alumina layers was necessary to meet the requirements of reduction of surface recombinations and to obtain optimized passivation results. Finally, various technological bricks necessary for the integration of these layers in the architecture of a silicon solar cell have been studied and developed
Lemenager, Maxime. "Atomic Layer Deposition of thin dielectric films for high density and high reliability integrated capacitors". Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI085.
Texto completoEnergy storage in embedded systems is still the subject of major R&D efforts as it requires a constant decrease in the volume of electronic components. It appears that the size of the discrete components, such as capacitors, is one of the brakes to the miniaturization of the final devices. Although technologies mainly based on silicon deep etching at the micrometric scale have made considerable progresses, they are now limited in terms of integration density. As a result, Murata IPS is developing a new 3D technology enabling a higher developed surface area. The use of such a matrix requires a MIM stack deposition technique such as ALD which is adapted to high aspect ratios. The aim of this thesis has been thus to integrate the MIM structure into the new 3D matrix while respecting the constraints inherent to the industry in order to give rise to the fifth generation of PICS™ technologies. The first challenge has been the achievement of sufficient step coverage of the films with an industrial equipment. A capacitance density greater than 1µF/mm² using a 10nm alumina film has been demonstrated. It also turns out that the TiN electrodes integration plays an important role on the 3D structure. Indeed, the mechanical stress had to be reduced to ensure the mechanical robustness of the structure, in particular by playing on the NH3 pulse. The metal-dielectric interfaces have also been the subject of an in-depth study where the influence of TiN oxidation during dielectric deposition has been shown and electrically characterized. This study has then led to the integration of an additional barrier material at the interfaces, producing capacitors with a 10-year lifetime under the intended voltage and temperature conditions
Jeloaica, Leonard. "Etude Ab initio des mécanismes réactionnels dans la phase initiale du dépôt par couches atomiques des oxydes à moyenne et forte permittivité sur silicium". Phd thesis, Université Paul Sabatier - Toulouse III, 2006. http://tel.archives-ouvertes.fr/tel-00110050.
Texto completoBernay, Cécile. "Faisabilité de la pile à combustible à oxyde solide à température intermédiaire pour l'application véhicule : dépôt de couches atomiques d'électrolyte : modélisation et tests de cellules". Paris 6, 2002. http://www.theses.fr/2002PA066557.
Texto completoJeloaica, Léonard. "Etude ab initio des mécanismes réactionnels dans la phase initiale du dépôt par par couches atomiques des oxydes à moyenne et forte permittivité sur silicium". Toulouse 3, 2006. http://www.theses.fr/2006TOU30077.
Texto completoThis work attempts to bring a new light on the understanding of some critical aspects of the physicochemical processes that control Alumina, Zirconia and Hafnia ALD growth, yet not sufficiently understood. These materials are addressed as potentially best candidates to replace gate dielectric SiO2 in the near future electronic applications. Most accurate ab initio correlated methods, like couple-cluster CCSD(T) and CISD(T), with different basis sets functions, as well as the available experimental data have been used for testing by a systematic study the accuracy and the reliability of DFT B3LYP functional. Our results have claimed this hybrid-DFT method to be chosen in predicting of high accurate static and dynamic properties throughout the family of organometallic-like (AlxCyHzOt) and transition metal-based (Zr/HfxClyOzHt) molecular systems. First systematic study of torsional potential surfaces of TMA has been performed and the related features of the hindered rotors of the methyl groups revealed with high accuracy. Laying on these accurate results we have also proposed least-squared fit methods to determine frequency scaling factors subject to different thermodynamic properties and/or thermal conditions. Many-step reaction mechanisms of ALD gas phase precursors of each of the three oxides with residual water, or regime of low pressure H2OÓALD pulses, have been studied in detail. Strong anharmonic internal movements of molecular species throughout the hydrolysis reactions have been observed and qualitatively discussed in relation with their possible effects on the reactions' kinetics. TMA/H2O reactions have been validated as strongly exothermic, while Hafnium and Zirconium tetrachlorides have founded to react endothermically with single H2O molecule. We have also studied in detail reaction mechanisms of the related on-surface ALD-complexes with water vapors. Our theoretical investigations address to the initial stage of ALD growth, more s pecifically on SiO2/Si(001)-2x1 like surfaces. The proposed many-step mechanisms, similar to those discussed for the gas phase, confirmed again the strong reactivity of H2O molecule with on-surface Aluminum hydroxymethylides, and responds strong endothemically as for the hydroxylation of Zirconium and Hafnium on-surface hydroxychlorides. The last two proved a very similar surface chemistry. Finally the cooperative effects of H2O molecules have been considered in our models of reactions, and have revealed dramatic influences on the reactivity Zirconium- and Hafnium hydroxychlorides surfaces. Our results proved the importance of both cooperative interactions of on-surface complexes and H2O molecules in the case of the Zirconia and HafniaÓALD growth, while for Aluminum oxide, presently considered ideal for ALD growth, these effects seem of secondary importance
Hallot, Maxime. "Micro-batteries tout solide en technologie Li-ion sur substrats Silicium planaires et tridimensionnels pour objets connectés". Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1I115.
Texto completoMiniaturized sensors for Internet of Things (IoT) application is in expansion since the last 10 years. All solid-state lithium-ion battery is a promising candidate. Nevertheless, in spite of high technological readiness level, planar micro-batteries suffer from a lack of energy density meaning that it is necessary to develop new architectures to fullfill the performances requirements. 3D structures is needed for such application and this work is focused on the synthesis of positives electrodes with high storage capacity and high operating voltage by Atomic layer deposition (ALD). In the frame of this work,we will rely structurals and electrochemicals properties by differents characterisations techniques for batteries materials
Skopin, Evgenii. "Etude des premiers instants du dépôt chimique par flux alternés (ALD) de films ZnO ultra minces sur In0,53Ga0,47As, dans le but d'optimiser la résistance de contact d'une structure MIS". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAY016/document.
Texto completoThis work focuses on the study of the initial stages of ZnO atomic layer deposition (ALD) on atomically flat (100) In0.57Ga0.43As surface, notably by using in situ synchrotron techniques. Due to high electron mobility, III-V InGaAs semiconductor has been recognized as a promising material to replace Silicon channel in the metal-oxide-semiconductor-field-effect transistors (MOSFET). Ultrathin ZnO layer on InGaAs can be used as a passivation layer at the interface with the gate transistor dielectric, as well as tunneling layer inserted in between metal/InGaAs contact to decrease the Schottky barrier height and the contact resistance. In the recent years, ALD technique based on self-limiting surface chemical reactions has received world-wide attention for manufacturing highly conformal and homogeneous thin films with sub-nanometer thickness control at low temperatures compatible with industry specifications. However, the growth behavior strongly differs depending on the substrate surfaces. Thus for the creation of few monolayers thick films, the study of ALD in the initial stages of growth is of particular interest for improving the understanding of the growth mechanisms.For that purpose, we have developed and upgraded a thermal ALD reactor (MOON:MOCVD/ALD growth of Oxide Nanostructures) dedicated to monitor the growth of materials by in situ characterization techniques. The MOON reactor can be moved to synchrotron centers for monitoring material growth in situ by using X-ray based techniques, notably X-ray fluorescence, X-ray absorption, XRR, and grazing incidence diffraction. Also, optical in situ techniques can be used in the laboratory. In this work, we show the results of experiments obtained at two synchrotron beamlines, i.e. SIRIUS (SOLEIL, Saint-Aubin (France)) and ID3 (ESRF, Grenoble (France)).We show that ZnO growth in the initial stages is inhibited by the (100) InGaAs substrate, leading to a transient regime prior to the steady ALD is achieved. We report a detailed investigation of this transient regime and find that an ultra-thin (~1-nm-thick) 2D layer is indeed fabricated but with a growth rate so low that one may believe that nothing has been deposited on the surface. We identify the structural and chemical properties of that ultra-thin layer. Only afterward does the substrate inhibited of type 2 growth mode begins: as the cycle number increases, the growth per cycle (GPC) increases, then reaches a maximum and level down to a constant value (steady growth). For a better understanding of the 3D growth mode by reproducing the experimental growth per cycle curves we have developed a geometric model that schematizes the growth of hemispheroid islands by ALD. We show that this model allows obtaining quantitative growth parameters.When water is used as a reactant, we showed that by changing the water flow during the ALD process, it is possible to control the time delay (or cycle number) prior to 3D growth begins. It is very likely that the water flow controls the density of hydroxyl groups on the InGaAs surface. We also demonstrated ZnO ALD for different InGaAs substrate temperatures. By combining in situ X-ray absorption and grazing incidence scattering techniques, we identified a short-range-order atomic structure of the ZnO material, with an embryonic ZnO wurtzite, prior to 3D growth, then a long-range-order structure is detected both by X-ray absorption and X-ray diffraction, together with the appearance of a microstructure. At higher growth temperature, outside of the ALD window, we observed the well-known ZnO texturing when the layer thickness increases.At last, we report on the use of ultrathin ZnO layers on InGaAs in the electrical contact structure. The contact resistance of metal/ZnO/InGaAs samples was measured using Transfer Length Method (TLM). We show that specific contact resistivity of Al/p-InGaAs pads is reduced by inserting a ZnO tunnel layer in between Al and p-doped InGaAs
Mastail, Cédric. "Modélisation et simulation du dépôt des oxydes à forte permittivité par la technique du Monte-Carlo cinétique". Toulouse 3, 2009. http://thesesups.ups-tlse.fr/989/.
Texto completoMiniaturizing components requires radical changes in the development of future micro electronic devices. In this perspective, the gate dielectric of MOS devices can become so thin as to be made permeable to leakage currents. One solution is to replace SiO2 by a material with a higher permittivity which would allow the use of thicker layers with similar results. My work presents a multi-scale modelling of the growth of HfO2 on Si by atomic layer (ALD), which allows me to link the nano-structuration of an interface with the process of development. I demonstrate that knowing how basic chemical processes work, thanks to DFT calculations, allows considering a process simulation based on the development of a Kinetic Monte Carlo software named "HIKAD. " Going beyond rather obvious mechanisms, I introduce the notion of densification mechanisms of deposited oxide layers. These mechanisms are the key element to understand how the growth of the layer in terms of coverage works. But even beyond that aspect, they allow to study the system's evolution towards a massive material, starting from molecular reactions. I shall discuss all those points in the light of recent experimental characterisation results concerning the deposition of hafnium oxides
Croizier, Guillaume. "Modélisation, réalisation et test de MEMS RF capacitif de puissance à base de dépôt diélectrique par ALD pour la conception de commutateur pour applications RADAR". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10210.
Texto completoRF MEMS are key components to improve the efficiency and size of numerous functions of microwave systems (Phase shifter, transmission/reception module, antennas array, reconfigurable systems, impedance matching…). To develop the next generation of RADAR systems, Thales takes special interest in the integration of capacitive RF MEMS devices to demonstrate reconfigurable functions with power handling capabilities up to 30 W. The work reported in this thesis did focus on the study of dielectric materials and deposition techniques to identify, integrate and demonstrate the advantages of promising dielectrics for capacitive RF MEMS power handling. The components fabrication aspects have also been studied, especially the impact of surface state quality on performances, power handling and devices failure mechanisms. Furthermore, this work did point out that with the integration of ALD material, power handling of capacitive RF MEMS is no longer limited by the capacitance dielectric. Furthermore, with the integration of ALD material the components design become the limiting factor for power handling, particularly the membrane thickness and the switch configuration. To open new prospects, several designs have been developed and studied to address these power handling limitations
Bugot, Cathy. "Elaboration d'oxydes et de sulfures à grande bande interdite pour les cellules photovoltaïques à base de Cu(In,Ga)Se2 par dépôt chimique en phase vapeur par flux alternés (ALD) activé par plasma". Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066499/document.
Texto completoThis thesis focuses on the development of innovative and efficient materials for the fabrication of the buffer layer of Cu(In,Ga)Se2 (CIGS) thin film solar cells. For the first time, In2(S,O)3 and Zn(O,S) thin films were synthesized by Plasma Enhanced Atomic Layer Deposition (PEALD) in order to substitute the conventional cadmium sulfide buffer layer. By creating reactive species, this deposition technique allows reactions which could not be possible using thermal ALD. The comparison of both methods allows the evaluation of their respective assets and constraints. For instance, In2(S,O)3 thin films could only be achieved using PEALD through exchange reaction mechanisms between oxygen radicals from the plasma and sulfur atoms of In2S3 growing film. In order to obtain CIGS/In2(S,O)3 solar cells with efficiencies of 11.9%, the initial deposition process was improved by correlating X-Ray Photoelectron Spectroscopy and Quadrupole Mass Spectrometry analyses. At the same time, the deposition temperature proved to have a crucial effect on CIGS/Zn(O,S)-ALD device opto-electronic properties and we evidenced the existence of two deposition temperature ranges, at Tdep < 160°C and Tdep > 200°C, where the performances are enhanced. In the low temperature range, the high performances were explained by specific Zn(O,S) properties, while at high temperature they are enhanced by favorable interdiffusion mechanisms at the CIGS/Zn(O,S) interface. Increasing the deposition temperature allowed the fabrication of CIGS/Zn(O,S) solar cells with efficiencies up to 15.6%
Bugot, Cathy. "Elaboration d'oxydes et de sulfures à grande bande interdite pour les cellules photovoltaïques à base de Cu(In,Ga)Se2 par dépôt chimique en phase vapeur par flux alternés (ALD) activé par plasma". Electronic Thesis or Diss., Paris 6, 2015. http://www.theses.fr/2015PA066499.
Texto completoThis thesis focuses on the development of innovative and efficient materials for the fabrication of the buffer layer of Cu(In,Ga)Se2 (CIGS) thin film solar cells. For the first time, In2(S,O)3 and Zn(O,S) thin films were synthesized by Plasma Enhanced Atomic Layer Deposition (PEALD) in order to substitute the conventional cadmium sulfide buffer layer. By creating reactive species, this deposition technique allows reactions which could not be possible using thermal ALD. The comparison of both methods allows the evaluation of their respective assets and constraints. For instance, In2(S,O)3 thin films could only be achieved using PEALD through exchange reaction mechanisms between oxygen radicals from the plasma and sulfur atoms of In2S3 growing film. In order to obtain CIGS/In2(S,O)3 solar cells with efficiencies of 11.9%, the initial deposition process was improved by correlating X-Ray Photoelectron Spectroscopy and Quadrupole Mass Spectrometry analyses. At the same time, the deposition temperature proved to have a crucial effect on CIGS/Zn(O,S)-ALD device opto-electronic properties and we evidenced the existence of two deposition temperature ranges, at Tdep < 160°C and Tdep > 200°C, where the performances are enhanced. In the low temperature range, the high performances were explained by specific Zn(O,S) properties, while at high temperature they are enhanced by favorable interdiffusion mechanisms at the CIGS/Zn(O,S) interface. Increasing the deposition temperature allowed the fabrication of CIGS/Zn(O,S) solar cells with efficiencies up to 15.6%
Grishin, André. "Réactivité interfaciale des composés à base de CeO2 dans des dispositifs électrochimiques hybrides fonctionnant à haute température". Thesis, Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEC002.
Texto completoThis study deals with high-temperature fuel cells that differ in the nature of the electrolyte: solid oxide (SOFC) and molten carbonates (MCFC). Despite the current maturity of these technologies, the high temperature degradation of materials slows down large-scale development. We mainly focused on the evolution of SOFC systems. This work investigates first the deposition of atomic layers (ALD) of cerium oxide doped with yttrium (known for its electrocatalytic properties at the anode) and their electrochemical characterization, in order to show the influence of their microstructure on the reactivity under a reducing atmosphere of hydrogen. The orientation of these layers showed a significant increase in their reactivity. In a second time we studied composite electrolytes oxide-carbonates and, more particularly, the evolution of their electrical behavior under different experimental conditions approaching the operation of the SOFC. We have been able to deduce the mechanisms governing the ionic conductivity under various atmospheres and highlighted the interest of a thin layer between anode and electrolyte in a single cell. In both cases, very significant results have been obtained allowing SOFC / MCFC hybrid systems, including highly oriented thin films, to be considered as competitors with existing devices
Bran, Julien. "Elaboration et caractérisation de nanostructures Cu-Co : corrélation avec les propriétés magnétorésistives". Phd thesis, Rouen, 2012. http://www.theses.fr/2012ROUES030.
Texto completoThis thesis concerned the study of the influence of the nanostructuration of the Cu-Co system on theirs magnetic and magnetoresistive properties. As a first step, the granular Cu80Co20 alloy was made in different forms: powders, thin films and nanowires. The alloy powders were produced by mechanical milling and thin films and nanowires by electrodeposition. This allowed to investigate, on one hand, the influence of the sample shape and, on the other hand, the influence of the elaboration technique on the nanostructure and the magnetic and magnetoresistive properties of the samples. In a second step, multilayered Cu/Co nanowires have also been made by electrodeposition. Concerning the granular alloys, the atom probe and transmission electron microscopy analyzes showed that no Cu-Co solid solution can be obtained. Indeed, studies in the literature on this type of materials are many, but few of them have been investigate down to the nanoscale. So, they concluded on the solid solution getting using the X-ray diffraction. In addition, the presence of a positive effect of the magnetoresistance at low applied magnetic field could be attributed to the presence of oxides in the material. Finally, this thesis has led to the development different experimental protocols for analysis at the nanoscale by transmission electron microscopy and atom probe tomography. Such analyzes are proved essential to the understanding and full correlation of magnetic and magnetoresistive properties
Bran, Julien. "Elaboration et caractérisation de nanostructures Cu-Co : corrélation avec les propriétés magnétorésistives". Phd thesis, Université de Rouen, 2012. http://tel.archives-ouvertes.fr/tel-00781148.
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