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Academic literature on the topic 'Émetteurs de lumière'
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Dissertations / Theses on the topic "Émetteurs de lumière"
Dhbaibi, Kais. "Systèmes pi-conjugués hélicèniques émetteurs de lumière circulairement polarisée." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S106.
Full textNew circularly polarized light emitter based on helicenic conjugated systems were synthesized and their optical and chiroptical properties were investigated. The first chapter is devoted to a bibliographic study describing the main properties of helicene, their synthetic access and the different types of applications of these molecules. The second chapter is dedicated to the preparation of new helicenic systems via the unprecedented association between achiral dye diketopyrrolopyrrole (DPP) and enantioenriched carbo[6]helicene. Excitonic coupling induced between DPPs pigments at the extremity of the helical center lead to red and nearinfrared circularly polarized luminescence. In the third chapter of this manuscript, we describe the synthesis, the optical and the chiroptical properties of a new family of helicene-naphthalimide helical chromophore. In particular, the effect of the solvent polarity on the chiral excited state will be discussed in detail via CPL characterization. The fourth chapter reports the evolution of the chiroptical responses of the helicene molecule with the spatial extension of the system and the variation of charge transfer character within these twisted systems. The functionalization of the carbo[6]helicene precursor with different electron donor and electron acceptor fragment is described. Photophysical, electrochemical and chiroptical properties is reported and analyzed
Sotta, David. "Milieux émetteurs de lumière et microcavité optique en silicium monocristalline sur isolant." Université Joseph Fourier (Grenoble), 2002. http://www.theses.fr/2002GRE10192.
Full textHadj, Alouane Mohamed Helmi. "Vers des émetteurs de lumière de longueurs d’ondes contrôlées à base de nanostructures InAs/InP." Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0045/document.
Full textLa complexité des systèmes de télécommunications par fibre optique évolue rapidement de façon à offrir plus de bande passante. Comme ce fut le cas pour l’industrie de la microélectronique, l’intégration de composants photoniques avancés est requise pour la production de composants de haute qualité aux fonctions multiples. C’est dans ce contexte, que s’inscrit ce travail qui consiste à contrôler la longueur d’onde d’émission des nanostructures InAs fabriquées dans deux types matrice InP. En effet, le premier volet de ce travail consiste à étudier les îlots quantiques InAs dans une matrice d’InP massif et sera dédié principalement à l’investigation de l’impact de l’interdiffusion sélective sur les propriétés optiques de bâtonnets quantiques (BaQs) élaborées par l’épitaxie par jets moléculaires (EJM). Un prototype d’une source modulable en longueur a été achevé à base de ces hétérostructures. Un modèles théorique qui traite de l’activation et du transfert thermique des porteurs à travers les BaQs de différentes tailles, créés par l’implantation ionique contrôlée a été développé. Les acquits obtenues dans le premier thème nous ont permis d’aborder une deuxième thématique très concurrentielle liée à l’étude des structures à Nanofils (NFs) InP et des hétérostructures à nanofils InAs/InP allant des structures 1D cœur/coquilles aux structures contenant une BQ InAs par nanofil InP par EJM en mode VLS (Vapeur-Liquide-Solide) sur substrat silicium. Nous avons révélé par différentes techniques spectroscopiques (PL, excitation de PL, microPL, PLRT) des propriétés optiques très spécifiques et particulièrement intéressantes : fort rapport surface/volume impactant sur les durées de vie des porteurs photocrés, présence de différentes phases cristallines (Wurtzite et Zinc-blende) au sein d’un même nanofil en fonction des conditions de croissance. Nous avons pu réaliser des couches actives des émetteurs à base de NFs dans lesquels nous avons privilégié la formation de segments d’InAs assimilables à des boîtes quantiques avec une forte localisation spatiale des porteurs et un très fort maintient de la luminescence en fonction de la température. Les mesures de PL montrent que les segments d’InAs émettent dans la gamme 1.3-1.55 µm ce qui montre le potentiel d’applications de ce type de nanofils dans une technologie des télécommunications par fibres optiques
Nguyen, Quoc Thai. "Émetteurs achromatiques pour le réseau d'accès optique haut débit multiplexé en longueurs d'onde." Phd thesis, Université Rennes 1, 2011. http://tel.archives-ouvertes.fr/tel-00598529.
Full textLongo, Antonio Valerio. "Development of alternate-current thin-film electroluminescent devices based on manganese-doped zinc sulfide quantum-dot technology." Electronic Thesis or Diss., Université Paris Cité, 2021. http://www.theses.fr/2021UNIP7253.
Full textIn this work we address the development of a light-emitting device, based on manganesedoped zinc sulfide nanoparticles, working under the application of an alternate-current voltage. Our device is based on a simple capacitive configuration implying a single layer of spin-cast nanoparticles sandwiched between two insulating thin films. In the first part of our work, we studied the nanoparticle system from a fundamental point of view. These nanoparticles, synthesized without the use of any surfactant by a microwave-assisted synthesis, are characterized by a phosphorescence activity in the orange region of the visible spectrum stemming from manganese dopants. In our work, we have observed and studied an enhancement of this optical activity under prolonged UV-light exposition. Our investigation allowed us to ascribe this phenomenon to a local lattice-strain effect around manganese chromophores due to a surface oxidation process induced by UV light. In a second part of our work, we focused on the dielectric properties of the insulating layers, consisting in an hafnium oxide film deposited by atomic layer deposition. By exploring several layer thicknesses and deposition temperatures, we have optimized the dielectric properties of the film, leading to more reliable and robust results. Moreover, we have also addressed the possibility of depositing an alumina layer by an in solution sol-gel approach, highlighting the main limitations of this technique. In the third part of the manuscript, the main characteristics of the complete electroluminescent device are addressed. More specifically, we recovered the orange emission band due to manganese doping, as well as the typical threshold behavior of the intensity of the emitted light as a function of the applied voltage. By exploiting structural characterization, impedance spectroscopy measurements and a careful comparison with theoretical works on similar devices, we have been able to state that the mechanism behind the observed light emission is a fieldinduced charge-creation process within the active layer only, followed by charge transport across the layer and radiative recombination within a single nanoparticle. Compared to previous works based on manganese-doped zinc sulfide nanoparticles, our key point has been the use of uncoated nanoparticles which allowed to achieve a very compact nanoparticle arrangement, favoring the physical mechanism mentioned above. Our work constitutes a step forward in the development of more compact, industrially feasible and eco-friendly light emitting devices
Hassoun, Ammar. "Développement de méthodes de synthèse de pyridylidènes de métaux en transition : vers une nouvelle classe de luminophores organométalliques." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS154.
Full textThese research investigations describe the development of several methods for the synthesis of organometallic compounds containing bidentate pyridylidene ligands. In a first step, the precursors of the pyridylidene ligands referred to herein as proligands are synthesized. These proligands possess an azacyclic moiety (pyridine, pyrimidine or benzimidazole) and a pyridinium moiety. The metallation of the pyridinium part in the α position of the nitrogen after activation / deprotonation of this C-H bond makes it possible to generate a pyridylidene function coordinated to the metal such as ruthenium(II), rhodium(III), iridium(III) and platinum(II). In particular, an unprecedented method of transferring these pyridylidenes by mercury(II) compounds has been developed. Firstly, the proligands react with mercury acetate to generate the pyridylidene bound to mercury(II), then the reaction with ruthenium(II), rhodium(III) and iridium(III) complexes makes it possible to highlight the transfer of pyridylidene. The compounds obtained were identified by NMR spectroscopy, infrared, mass and in several cases by X-ray diffraction on single crystals. Some of the precursor proligands of the pyridylidene ligands in the target complexes as well as most of the complexes obtained exhibit unusual luminescence phenomena with respect to the reference compounds in the literature. This may be due to the peculiar zwitterionic structure of the pyridylidene ligands used. In particular, when they are emissive, the photoluminescence spectra show very broad emission bands, which sometimes spread out over the whole range of the visible region. This paves the way for the discovery of new single-component panchromatic emitting materials that are very rare in the literature
Guellil, Imene. "Nano-fonctionnalisation par FIB haute résolution de silicium." Electronic Thesis or Diss., Aix-Marseille, 2022. http://www.theses.fr/2022AIXM0361.
Full textThe goal of this work is to develop a process for the elaboration of silicon-germanium (SiGe) quantum dots (QDs) with compositions ranging from Si to pure Ge, and allowing to obtain semiconducting QDs with sufficiently small sizes to obtain quantum confinement. For this purpose, we have used a combination of different techniques: molecular beam epitaxy, focused ion beam lithography (FIBL) and heterogeneous solid state dewetting. In this context, the aim of this research is on the one hand to develop a new FIB that can be coupled to the ultra-high vacuum molecular beam epitaxy growth chamber, and on the other hand to realize two applications: (i) nanopatterns for the self-organisation of Si and Ge QDs and (ii) nano-implantations of Si and Ge. We used FIBL with energy-filtered liquid metal alloy ion sources (LMAIS) using non-polluting ions (Si and Ge) for the milling of conventional microelectronic substrates such as SiGe on silicon-on-insulator (SGOI). The nanopatterns must be totally free of pollution and with variable and perfectly controlled characteristics (size, density, depth). The morphology of the nanopatterns is then characterized in-situ by scanning electron microscopy (SEM), and the depth is determined ex-situ by atomic force microscopy (AFM). The nanopatterns made by FIBL were compared on the one hand to plasma etchings with He and Ne and on the other hand to the etchings obtained by electronic lithography (EBL). Nanoimplantations of Si and Ge ions were realised in diamond and in ultra-thin SGOI for the fabrication of local defects
Du, Weiwei. "Development of new organic emissive materials for organic light-emitting diodes and organic laser applications." Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS215.
Full textIn this work, new organic emitting materials were designed for the organic light-emitting diodes (OLED) or laser applications. First, three series of through-space TADF (Thermally Activated Delayed Fluorescence) molecules based on different cyclophane cores have been successfully prepared. Their chemical structures were confirmed by Nuclear Magnetic Resonance (NMR) and high-resolution mass spectrometry (HRMS). The photophysical properties were investigated in solution and solid state. In these systems, the intramolecular charge transfer was produced via intramolecular through-space interactions between the donor and acceptor units, and their study revealed that most of these derivatives exhibit a TADF character. The electroluminescence properties of some derivatives were also investigated in OLED configuration and promising results were evidenced. Second, a new set of soluble gain molecules based on extended π-conjugated or three dimensional (3D) structures have been successfully synthesized for laser applications. Their chemical structures were confirmed by Nuclear Magnetic Resonance (NMR), high-resolution mass spectrometry (HRMS) and elemental analysis. High luminescence properties such as high photoluminescence quantum yields (PLQY) and short fluorescence lifetimes were demonstrated in both solution and solid state for most of the derivatives. Finally, these emitting materials exhibits good amplified spontaneous emission (ASE) properties with low thresholds and optically pumped laser devices were fabricated based on some derivatives of the series
Akra, Ahiram el. "Croissance de boîtes quantiques In(Ga)As sur substrats de silicium et de SOI pour la réalisation d'émetteurs de lumière." Phd thesis, Ecole Centrale de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00952829.
Full textLi, Haixia. "Design and characterization of new pyridazine materials for OLEDs and OSLs applications." Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS227.
Full textIn this work, new organic emitting materials have been developed for applications in the field of light emitting diodes or organic lasers. First of all, several molecules of the Donor-Acceptor type incorporating various electro-deficient nitrogenous hearts have been successfully prepared, their design being designed with the aim of obtaining TADF emitters. Their photophysical properties have been studied in solution and in the solid state. In these structures, intramolecular charge transfer is produced via intermolecular interactions between the D and A groups, and their study revealed that some of them exhibit a TADF character. The electroluminescence properties of the most promising compounds have also been studied in OLED configuration, even if to date the observed yields remain low. Then, a series of gain molecules based on pi-conjugated structures, still consisting of nitrogenous cores, have been successfully synthesized for laser applications. Their chemical structures have been characterized by nuclear magnetic resonance (NMR) and high-resolution mass spectroscopy (HRMS). Good luminescence properties such as high quantum photoluminescence yields (PLQY) and short fluorescence lifetimes have been demonstrated in solution and in the solid state for most derivatives. Finally, some emissive materials exhibit good amplified spontaneous emission (ASE) properties with low threshold values, and optically pumped laser devices could also be made from some of the derivatives of the series