The objective of this thesis was to develop novel technologies for measuring the physical characteristics of high-speed pulse trains, for use in performance monitoring applications. This thesis describes the development of three separate techniques that perform measurements in either the time domain, frequency domain or the phase space of the optical signal. The first section investigates phase-sensitive pulse measurement techniques. A high- resolution SHG-FROG apparatus was custom-designed to measure 40GHz RZ pulse trains, from which an operational characterisation of a Mach-Zehnder modulator (MZM) was realised. A numerical model of a nonlinear pulse compressor was developed to compress 40GHz RZ pulses from 8.5ps down to 3.4ps. These pulses were time-division multiplexed to 80GHz, and phase-retrievals of the 80GHz pulse trains were measured. A comparison between the techniques of SHG-FROG and linear spectrogram has been undertaken for 10GHz pulse sources, exposing SHG-FROG's weaknesses at this particular repetition rate. The second section investigates a simple, time-averaged, nonlinear detection technique. Two-photon absorption in a GaAs/InGaAs quantum-well laser diode was used to measure the duty cycle (and by extension, the pulse duration) of a range of pulse sources. This technique was further developed to measure the extinction ratio of NRZ pulse trains. Additionally, the pulse duration of a mode-locked laser source was measured using the nonlinear absorption in a 1-m length of As2Se3 Chalcogenide glass fiber. This demonstrates that the nonlinear properties of this glass may well find application in future instrumentation. The third section investigates the development of an ultra-high resolution swept heterodyne spectrometer. This spectrometer was used to spectrally-distinguish repetitive 8-bit NRZ patterns at 2.5Gbit/s. It was also used to measure the chirp parameter of an X-cut LiNbO3 MZM, revealing a chirp parameter of απ/2 < 0.1 across a modulation band- width of 250-2500MHz. Additionally, the distinctive CW spectrum of a DFB laser diode was measured. Analysis of the measured CW spectrum yielded a linewidth enhancement factor of α≃ 1.8 and also the relative intensity noise of the DFB laser diode.

The objective of this thesis was to develop novel technologies for measuring the physical characteristics of high-speed pulse trains, for use in performance monitoring applications. This thesis describes the development of three separate techniques that perform measurements in either the time domain, frequency domain or the phase space of the optical signal. The first section investigates phase-sensitive pulse measurement techniques. A high- resolution SHG-FROG apparatus was custom-designed to measure 40GHz RZ pulse trains, from which an operational characterisation of a Mach-Zehnder modulator (MZM) was realised. A numerical model of a nonlinear pulse compressor was developed to compress 40GHz RZ pulses from 8.5ps down to 3.4ps. These pulses were time-division multiplexed to 80GHz, and phase-retrievals of the 80GHz pulse trains were measured. A comparison between the techniques of SHG-FROG and linear spectrogram has been undertaken for 10GHz pulse sources, exposing SHG-FROG's weaknesses at this particular repetition rate. The second section investigates a simple, time-averaged, nonlinear detection technique. Two-photon absorption in a GaAs/InGaAs quantum-well laser diode was used to measure the duty cycle (and by extension, the pulse duration) of a range of pulse sources. This technique was further developed to measure the extinction ratio of NRZ pulse trains. Additionally, the pulse duration of a mode-locked laser source was measured using the nonlinear absorption in a 1-m length of As2Se3 Chalcogenide glass fiber. This demonstrates that the nonlinear properties of this glass may well find application in future instrumentation. The third section investigates the development of an ultra-high resolution swept heterodyne spectrometer. This spectrometer was used to spectrally-distinguish repetitive 8-bit NRZ patterns at 2.5Gbit/s. It was also used to measure the chirp parameter of an X-cut LiNbO3 MZM, revealing a chirp parameter of απ/2 < 0.1 across a modulation band- width of 250-2500MHz. Additionally, the distinctive CW spectrum of a DFB laser diode was measured. Analysis of the measured CW spectrum yielded a linewidth enhancement factor of α≃ 1.8 and also the relative intensity noise of the DFB laser diode.

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abstract: This PhD thesis consists of three main themes. The first part focusses on modeling of Silver (Ag)-Chalcogenide glass based resistive memory devices known as the Programmable Metallization Cell (PMC). The proposed models are examined with the Technology Computer Aided Design (TCAD) simulations. In order to find a relationship between electrochemistry and carrier-trap statistics in chalcogenide glass films, an analytical mapping for electron trapping is derived. Then, a physical-based model is proposed in order to explain the dynamic behavior of the photodoping mechanism in lateral PMCs. At the end, in order to extract the time constant of ChG materials, a method which enables us to determine the carriers’ mobility with and without the UV light exposure is proposed. In order to validate these models, the results of TCAD simulations using Silvaco ATLAS are also presented in the study, which show good agreement. In the second theme of this dissertation, a new model is presented to predict single event transients in 1T-1R memory arrays as an inverter, where the PMC is modeled as a constant resistance while the OFF transistor is model as a diode in parallel to a capacitance. The model divides the output voltage transient response of an inverter into three time segments, where an ionizing particle striking through the drain–body junction of the OFF-state NMOS is represented as a photocurrent pulse. If this current source is large enough, the output voltage can drop to a negative voltage. In this model, the OFF-state NMOS is represented as the parallel combination of an ideal diode and the intrinsic capacitance of the drain–body junction, while a resistance represents an ON-state NMOS. The proposed model is verified by 3-D TCAD mixed-mode device simulations. In order to investigate the flexibility of the model, the effects of important parameters, such as ON-state PMOS resistance, doping concentration of p-region in the diode, and the photocurrent pulse are scrutinized. The third theme of this dissertation develops various models together with TCAD simulations to model the behavior of different diamond-based devices, including PIN diodes and bipolar junction transistors (BJTs). Diamond is a very attractive material for contemporary power semiconductor devices because of its excellent material properties, such as high breakdown voltage and superior thermal conductivity compared to other materials. Collectively, this research project enhances the development of high power and high temperature electronics using diamond-based semiconductors. During the fabrication process of diamond-based devices, structural defects particularly threading dislocations (TDs), may affect the device electrical properties, and models were developed to account of such defects. Recognition of their behavior helps us understand and predict the performance of diamond-based devices. Here, the electrical conductance through TD sites is shown to be governed by the Poole-Frenkel emission (PFE) for the temperature (T) range of 323 K ˂ T ˂ 423 K. Analytical models were performed to fit with experimental data over the aforementioned temperature range. Next, the Silvaco Atlas tool, a drift-diffusion based TCAD commercial software, was used to model diamond-based BJTs. Here, some field plate methods are proposed in order to decrease the surface electric field. The models used in Atlas are modified to account for both hopping transport in the impurity bands associated with high activation energies for boron doped and phosphorus doped diamond. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2017

abstract: Microwave (MW), thermal, and ultraviolet (UV) annealing were used to explore the response of Ag structures on a Ge-Se chalcogenide glass (ChG) thin film as flexible radiation sensors, and Te-Ti chalcogenide thin films as a material for diffusion barriers in microelectronics devices and processing of metallized Cu. Flexible resistive radiation sensors consisting of Ag electrodes on a Ge20Se80 ChG thin film and polyethylene naphthalate substrate were exposed to UV radiation. The sensors were mounted on PVC tubes of varying radii to induce bending strains and annealed under ambient conditions up to 150 oC. Initial sensor resistance was measured to be ~1012 &Omega;; after exposure to UV radiation, the resistance was ~104 &Omega;. Bending strain and low temperature annealing had no significant effect on the resistance of the sensors. Samples of Cu on Te-Ti thin films were annealed in vacuum for up to 30 minutes and were stable up to 500 oC as revealed using Rutherford backscattering spectrometry (RBS) and four-point-probe analysis. X-ray diffractometry (XRD) indicates Cu grain growth up to 500 oC and phase instability of the Te-Ti barrier at 600 oC. MW processing was performed in a 2.45-GHz microwave cavity on Cu/Te-Ti films for up to 30 seconds to induce oxide growth. Using a calibrated pyrometer above the sample, the temperature of the MW process was measured to be below a maximum of 186 oC. Four-point-probe analysis shows an increase in resistance with an increase in MW time. XRD indicates growth of CuO on the sample surface. RBS suggests oxidation throughout the Te-Ti film. Additional samples were exposed to 907 J/cm2 UV radiation in order to ensure other possible electromagnetically induced mechanisms were not active. There were no changes observed using XRD, RBS or four point probing. / Dissertation/Thesis / M.S. Materials Science and Engineering 2013

Le moyen infrarouge est la région spectrale comprise entre 2 et 20 µm. Cette gamme de longueurs d'onde présente un fort intérêt scientifique grâce à la présence des transitions vibrationnelles fondamentales caractéristiques d'espèces moléculaires en phase liquide ou gazeuse. Les capteurs en optique intégrée sont devenus une excellente alternative pour la détection in situ car ils présentent certains avantages sur les autres types de capteurs, tels que l'intégration des éléments dans un dispositif compact. Ils sont capables d'effectuer des détections sélectives et quantitative dans divers domaines sociétaux tels que la santé, la défense et l'environnement. Dans cette thèse, nous présentons la conception, la fabrication et la caractérisation à 7.7 µm d'un transducteur spectroscopique intégré à base de verres de chalcogénures. Des couches à base de Ge-Sb-Se ont été déposées par pulvérisation cathodique RF magnétron. Des guides d'onde de type ridge ont ensuite été mise en forme, par photolithographie et gravure sèche (gravure ionique réactive) avec un plasma de CHF3. Différentes structures ont ainsi pu être réalisées : guides droits, jonctions Y, guide en spirale ou encore guides en S. En outre, la propagation guidée a été observé à 7.7 µm et des pertes de propagation égales à 2.5 dB/cm ont été mesurées à cette longueur d'onde. Enfin, des substances chimiques en phase liquide (isopropanol et acide acétique dissous dans du cyclohexane) ont été détectées par onde évanescente. Des limites de détection égales à 2 %v/v et 0.2 %v/v ont été, respectivement, démontrées à 7.7 µm pour l'isopropanol et l'acide acétique. Enfin, des simulations ont démontré le potentiel de ce capteur intégré pour la détection de substances polluantes contenues dans l'eau ou dans l'air avec des limites de détection inférieures à celles imposées par les normes internationales de l'environnement. L'ensemble de ces résultats représente une première étape prometteuse vers le développement d'applications dans le moyen Infrarouge au sein du laboratoire Foton. / The mid-infrared is a spectral range (2-20 µ m) of great scientific and technological interest. Indeed, the strong vibrational absorption bands of numerous molecules overlap this wavelength range. Thus, the mid-infrared has become in the last years a suitable solution for chemical sensing applications in gas or liquid phase. Furthermore, on-chip sensors provide several advantages over other kind of sensors, such as high integration of elements in a compact device and low fabrication cost by an easy-going to mass production. They could allow quantitative, sensitive and selective detection for health, defense and environmental applications. This thesis presents the design, fabrication and optical characterization at 7.7 µ m of a spectroscopic optical integrated sensor based on chalcogenide glasses. Ge-Sb-Se multilayered structures were deposited by RF magnetron sputtering. Using i-line photolithography and fluorine-based reactive ion etching (RIE-ICP), ridge waveguides were processed as straight waveguide, Y-junction, spiral and S-shape waveguides. Single-mode optical propagation at 7.7 µ m was observed by optical near-field imaging and optical propagation losses of 2.5 dB/cm were measured. Finally, chemical substances in liquid phase (isopropanol - and acetic acid, both dissolved in cyclohexane) were detected at 7.7 µ m by evanescent field. Limits of detection of 2 %v/v and 0.2 %v/v are demonstrated, respectively, for isopropanol and acetic acid. Furthermore, simulations were performed to assess the potential of the optical integrated sensor to achieve limits of detection lower than environmental and health standards for air and water pollutants. These results represent a first promising step towards the development of mid-infrared applications at the Foton laboratory.

Ce travail de thèse s’inscrit dans le cadre d'études théoriques ayant pour but l’établissement de la structure des chalcogénures binaires et ternaires sous différentes conditions thermodynamiques. Des techniques de modélisation numérique ab-initio ont été employées. En particulier, nous avons utilisé la dynamique moléculaire par premiers principes selon l’approche de Car et Parrinello ainsi que sa version dite "deuxième génération". La première partie est consacrée à l’étude des chalcogénures binaires, notamment les verres GeSe2 et GeSe4 sous pression ainsi qu'à l’étude des effets des forces de van der Waals et des fonctionnelles d’échange et corrélation DFT sur la structure de l’amorphe GeTe4. Dans la deuxième partie, l’intérêt a été porté à l’étude d'un matériau à changement de phase récemment proposé par les expérimentateurs comme un bon candidat pour le stockage de données, le ternaire Ga4Sb6Te3. / This thesis reflects efforts toward an accurate understanding of the atomic scale structure of chalcogenide glasses. These compounds have an impact on electronics, optoelectronics and memory devices. I resorted to the most advanced first-principles molecular dynamics simulations such as the standard Car-Parrinello method as well as its second generation version. In the first part of this thesis we provide a detailed study of the topological changes undergone under pressure by glassy GeSe2 and by glassy GeSe4. Structural transition and bonding features are described and compared to the results of neutron and X-ray diffraction experiments. Furthermore, in the case of glassy GeTe4 we demonstrated that the inclusion of van der Waals forces leads to substantial improvements in the description of the structure. In the second part of this thesis, we established the atomic-scale organization of a promising candidate for phase change memory applications, glassy Ge4Sb6Te3.

The complete understanding of a clusters electronic structure, the primary mechanisms for its properties and stabilization is necessary in order to functionalize them for use as building blocks within novel materials. First principle theoretical studies have been carried out upon the electronic properties of CrxTey (x = 1 – 6, y = 0 – 8, x + y ≤ 14), as well as for the larger triethylphosphine (PEt3) ligated cluster system of Cr6Te8(PEt3)6. Together, we aim to use the information garnered from the smaller clusters to address the underlying behavior of the ligated Cr6Te8(PEt3)6. Additionally, the properties of this larger cluster will be used to further understand its role when paired with C60 within the binary cluster assembled material. The stability and macroscopic properties of the Cr6Te8(PEt3)6 cluster, have been found to be sensitive to type of passivating ligand. As will be shown, the ground state structures of Crn atoms are sensitive to both the number and position of bonded Te atoms. Moreover, that this sensitivity carries over into larger cluster sizes, and at several size intervals produces clusters with high magnetization. To this, we add the investigation into the manipulation of the Cr6Te8 cluster geometry and its properties through various ligands, such as PH3, CO, and CN. It will show, that in altering these ligands there is a modification to the clusters valence shell count, which in turn alters its ionization potential and electron affinity. Additionally, although the ionization potential and electron affinity have changed for the Cr6Te8(PEt3)6 cluster, it has been found that its high magnetization does not.

Ces dernières années ont vu un intérêt croissant pour l'application de nanoparticules de chalcogénure (IP) (par exemple Se, Te) dans divers secteurs industriels, y compris l'énergie, les aciers, le verre et le raffinage du pétrole. Le chalcogénure métallique fluorescent (par exemple CdSe, CdTe) NPs sont utilisés dans les cellules solaires, les capteurs optoélectroniques et aussi dans le domaine de la biologie et de la médecine pour l'imagerie ou de détection comprenant biolabelling. En outre, en raison de la forte toxicité des oxyanions chalcogènes (à savoir, sélénite, séléniate, tellurites et tellurate), leur libération dans l'environnement est très préoccupante. Ainsi, mettre l'accent a été donné dans cette thèse sur le développement d'un nouveau procédé de synthèse microbienne des NPs chalcogénures en combinant le traitement biologique des eaux usées Se / Te contenant avec biorecovery de Se / Te sous la forme de Se / Te chalcogénures NPs.Une attention particulière a été accordée pour étudier l'effet des métaux lourds (par exemple Cd, Zn et Pd) co-contaminants sur bioréduction sélénite par anaérobie granulaire boues. boue anaérobie granulaire capable de réduire sélénite de séléniure de, en présence de Cd a été enrichie pour la synthèse microbienne de CdSe IP. Il était évident que lorsque Cd est présent avec sélénite, soit il forme un complexe de Se-Cd par adsorption sur biogène Se (0) des nanoparticules après EME-oxyanion ou bioréduction il réagit avec le séléniure aqueux (HSe-) pour former CdSe. Les spectres d'absorption et de fluorescence de la phase aqueuse à confirmer la présence de CdSe IP dans la phase aqueuse. spectroscopie Raman et X-ray spectroscopie de photoélectrons (XPS) analyse l'appui de cette constatation. La formation d 'une couche alliée de CdSxSe1-x à l'interface entre le noyau et CdS CdSe shell dans la boue a également été observée. Des études détaillées sur les substances polymères extracellulaires (EPS) révèlent que la teneur en protéines et en polysaccharides comme augmenté dans les EPS extraites de boues enrichi tandis que les substances humiques comme diminué. chromatographie d'exclusion de taille (SEC) des EPS révèle en outre une empreinte distincte pour les protéines et les substances humiques-like, avec une augmentation de haute teneur en protéines comme poids moléculaire et l'apparition de nouveaux pics pour les substances humiques comme dans les EPS après l'enrichissement.Anaérobie des boues lit granulaire (UASB) à courant ascendant a été utilisé pour la première fois pour le retrait continu de tellurite des eaux usées synthétique et la récupération du Te comme biogénique Te (0). La spectroscopie aux rayons X à dispersion d'énergie (EDS), diffraction des rayons X (XRD) et analyse spectroscopique Raman de la biomasse a confirmé le dépôt de Te (0) dans la biomasse. Il était évident que la majorité du Te (0) a été piégé principalement dans l'EPS entourant la biomasse, qui peut être facilement séparé par centrifugation / Recent years have seen a growing interest in the application of chalcogenide nanoparticles (NPs) (e.g. Se, Te) in various industrial sectors including energy, steels, glass and petroleum refining. The fluorescent metal chalcogenide (e.g. CdSe, CdTe) NPs are used in solar cells, optoelectronic sensors and also in the field of biology and medicine for imaging or sensing including biolabelling. Moreover, due to the high toxicity of chalcogen oxyanions (i.e., selenite, selenate, tellurite and tellurate), their release in the environment is of great concern. Thus, emphasize was given in this thesis on the development of a novel microbial synthesis process of chalcogenide NPs by combining biological treatment of Se/Te-containing wastewaters with biorecovery of Se/Te in the form of Se/Te chalcogenides NPs.A special focus was given to study the effect of heavy metal (e.g. Cd, Zn and Pd) co-contaminants on selenite bioreduction by anaerobic granular sludge. Anaerobic granular sludge capable of reducing selenite to selenide in the presence of Cd was enriched for the microbial synthesis of CdSe NPs. It was evident that when Cd is present along with selenite, it either forms a Se-Cd complex by adsorption onto biogenic Se(0) nanoparticles after Se-oxyanion bioreduction or it reacts with aqueous selenide (HSe-) to form CdSe. The absorption and fluorescence spectra of the aqueous phase confirm the presence of CdSe NPs in the aqueous phase. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis support this finding. The formation of an alloyed layer of CdSxSe1-x at the interface between the CdSe core and CdS shell in the sludge was also observed. Detailed studies on the extracellular polymeric substances (EPS) reveal that the protein and polysaccharide-like content increased in the EPS extracted from enriched sludge while humic-like substances decreased. Size exclusion chromatography (SEC) of EPS further reveals a distinct fingerprint for proteins and humic-like substances, with increase in high molecular weight protein-like and the appearance of new peaks for humic-like substances in the EPS after the enrichment.An upflow anaerobic granular sludge bed (UASB) reactor was used for the first time for continuous removal of tellurite from synthetic wastewater and the recovery of Te as biogenic Te(0). Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and Raman spectroscopic analysis of biomass confirmed the deposition of Te(0) in the biomass. It was evident that the majority of the Te(0) was trapped predominantly in the EPS surrounding the biomass, which can be easily separated by centrifugation

Face à la raréfaction des énergies fossiles, l’industrie automobile se trouve dans l’obligation de réduire la consommation des véhicules. L’une des idées est de récupérer l’énergie perdue sous forme d’échauffements grâce à la thermoélectricité. L’objectif de ces travaux est l’implantation d’un module thermoélectrique au niveau du radiateur afin d’en récupérer la chaleur dans le cadre d’un projet de recherche financé par Valéo Systèmes Thermiques et l’ADEME. La conception des radiateurs nécessite des épaisseurs supérieures à la centaine de micromètres de matériaux thermoélectriques afin d’en optimiser l’espace disponible. L’électrodéposition est apparue comme la technologie la plus adaptée car elle permet de déposer les matériaux directement sur l’ailette. Cette étude est consacrée aux dépôts électrochimiques de chalcogénures de bismuth (Bi2Te3 et Bi0,5Sb1,5Te3), matériaux les plus performants aux températures de fonctionnement de l’échangeur thermique. La première partie de ces travaux concerne la faisabilité de l’obtention de films d’épaisseurs supérieures à 100 µm et leurs caractérisations : stœchiométrie, structures et propriétés thermoélectriques. L’utilisation originale d’une anode soluble permet l’obtention de films de Bi2Te3 de près de 400 µm. Pour le composé ternaire, la synthèse consiste en une succession de couches de composés différents (Bi0,25Sb0,75-Te0), avant de procéder à leur interdiffusion via un traitement thermique. La dernière partie concerne la réalisation d’un module thermoélectrique. Les multiples étapes de lithographie et de synthèses électrochimiques ont été étudiées afin d’obtenir un module adapté aux échangeurs thermiques. Les caractérisations préliminaires de leurs propriétés montrent des résistances élevées et plusieurs voies d’améliorations sont proposées / In order to face the rarefaction of fossil fuels, the automotive industry has to find new ways to reduce their vehicle consumption. One of the possible ideas is to recover the energy that is lost as heating by using thermoelectricity. The aim of this work is to set-up thermoelectric generators into the radiator in order to recover this lost heat in a frame of research project financially supported by Valéo Systèmes Thermiques and ADEME. The radiator design requires thermoelectric materials thicknesses up to hundred micrometers in order to optimize the available space. Electroplating seems to be the best way to synthesize those materials directly onto the radiator fins. This study focuses on the electroplating of the best thermoelectric materials adapted to the operating temperatures of the heat exchanger: bismuth chalcogenides (Bi2Te3 and Bi0,5Sb1,5Te3). Firstly, a study has been carried out in order to synthesize thick layers above 100 µm of those two materials. Stoichiometry and thermoelectric properties were also determined. The original use of a soluble anode permitted to obtain 400 µm thick Bi2Te3 films. For the ternary compound, the synthesis consisting in a succession of thin layers of Bi0,25Sb0,75 and Te0, before their interdiffusion by annealing, is also presented. Finally, the last part covers the study carried out on the realization of the thermoelectric generators. The multiple stages of lithography and electrochemical syntheses were studied in order to obtain a module adapted to the heat exchanger. The first characterizations evidence high internal resistances and different ways to improve them are also presented