Dans le contexte du stockage profond des déchets radioactifs de haute et moyenne activité à vie longue en France, l’argilite de Bure (Arg) a été choisie comme roche hôte notamment pour ses propriétés de rétention des radionucléides. Or, cette roche argileuse dite du Callovo-Oxfordien (COx) contient naturellement de la matière organique (MO). Le but de cette thèse est d’évaluer l’influence de la MO naturelle mobile sur la rétention sur l’argilite de l’europium, analogue classique des actinides trivalents des déchets vitrifiés. Trois molécules organiques sont étudiées : les acides subérique, sorbique et tiglique, acides organiques de faible poids moléculaire identifiés dans l’eau porale naturelle du COx. Toutes les expériences ont été réalisées dans un milieu simulant l’eau du COx (pH=7,5 ; I=0,1 mol/L ; PCO2 =10^(-2) bar).La caractérisation de notre échantillon d’argilite montre sa conformité avec les études précédentes de la zone d’intérêt et que le pH de 7,5 est incontournable pour ne pas dénaturer la roche. L’étude du système Eu-MO montre que les acides organiques n’ont pas d’influence sur la spéciation de l’europium dans l’eau de COx. L’étude expérimentale de l’interaction Eu-Arg confirme que la rétention se fait par sorption sur l’argilite (CEu<6.10-6mol/L) et précipitation dans l’eau de COx (CEu>6.10^(-6)mol/L). Le coefficient de distribution Rd, qui quantifie la sorption, est de 170 ± 30 L/g, valeur élevée conforme aux valeurs documentées sur des argilites naturelles. Enfin, l’étude du système ternaire Eu-MO-Arg montre une légère augmentation de la rétention de Eu en présence de matière organique. Cet effet synergique est très satisfaisant du point de vue de la sûreté du stockage : la présence de ces petits acides organiques naturels ne remet pas en question les propriétés de rétention de l’argilite vis-à-vis de l’europium et des actinides trivalents. / Bure clay rock (CR) was chosen as host rock for the French high and intermediate level long lived radioactive waste repository. This choice is mostly explained by the retention ability of the Callovo-Oxfordian rock (COx). Bure clay rock contains natural organic matter (OM) that could have an influence on radionuclide retention. The aim of this work is to assess the influence of natural mobile OM on the retention of Eu on clay rock. Eu was chosen as a chemical model for trivalent actinides contained in vitrified waste. Three organic molecules were studied: suberic, sorbic and tiglic acids, small organic acids identified in COx pore water. All the experiments were carried out in an environment recreating COx water (pH=7.5 ; I=0.1 mol/L ; PCO2 =10^(-2) bar).Clay rock sample characterization showed that the sample used in this work was similar to those previously extracted from the area of interest and that it was necessary to maintain pH at 7.5 to avoid altering the clay rock. The Eu-OM system study indicated that organic acids had no influence on Eu speciation in COx water. The Eu-CR system experimental study confirmed that retention implied sorption on CR (CEu<6.10^(-6)mol/L) and precipitation in COx water (CEu>6.10-6mol/L). Distribution coefficient Rd (quantifying sorption) was estimated at 170 ± 30 L/g. This high value is consistent with literature values obtained on clay rocks. The ternary Eu-OM-CR system study showed a slight increase of sorption in the presence of organic matter. This synergistic effect is very satisfactory in terms of storage security: the presence of small organic acids in clay rock does not question retention properties with respect to europium and trivalent actinides.

Les verres de phosphates de zinc et gallium contenant de l’argent ont permis des développements originauxau travers de la structuration d’architectures photoniques multi-échelles innovantes en volume, en surfaceou sur fibre, et également à travers l’ingénierie de composition chimique du matériau. Un taux accru d’oxyded’argent permet de maximiser la quantité de paires au sein de la matrice vitreuse lors de la synthèse dumatériau. Ce dimère favorise les processus d’agrégation conduisant à la formation d’espèces lors del’interaction locale entre le verre et le laser femtoseconde infrarouge. Une étude par spectroscopie RPEmenée sur des échantillons irradiés par des sources ionisantes a permis de montrer que le débit de dose estprépondérant quant au contrôle des processus chimiques. Des centres à électron et à trou sont les espècesmajoritairement stabilisées à faible débit de dose, alors que la formation d’agrégats d’argent luminescentsintervient pour des puissances crête élevées typiques des lasers ultra-courts. Le caractère local de lastructuration par Direct Laser Writing a permis de créer des objets 3D originaux. L’analyse fine de ladistribution chimique au sein d’objets fluorescents a permis de montrer clairement une zone de déplétion enions argent au centre. Les effets de migration d’ions depuis le centre du faisceau laser vers le bord externea ainsi été mis en évidence. Le dopage des verres photosensibles par des ions europium a permis de montrerdes effets de synergie entre agrégats d’argent photo-inscrits et lanthanides trivalent. En effet, une exaltationde l’émission de luminescence de ces derniers à l’endroit des structurations laser a été mesurée. / The silver-containing phosphate glasses allowed original developments throughout the microstructuring ofarchitectures for innovative photonic in the volume, at the surface or in the fibered material. The chemicalengineering of the material plays an important role from this point of view. An increasing silver oxide ratioleads to an important quantity of pairs in the pristine glass matrix. This dimer in favor of the aggregationprocess bringing to the production of species during the interaction between the glass and the infraredfemtosecond laser. A study conducted by EPR spectroscopy on irradiated samples (ionizing sources)demonstrated that the dose rate is predominant for the control of the involved chemical process. Mainly,electron and holes are stabilized at low dose rate whereas the formation of luminescent silver clusters occursfor high peak power typical of ultra-short lasers. The Direct Laser Writing process allows local structuring ofthe matter and resulted in original tridimensional patterns. The fine chemical distribution analysis insideannular fluorescent objects clearly showed a depletion zone of the silver concentration in the center. Ionicmigration effects from the center towards the edges of the laser beam are then highlighted. The Eu3+-dopedphotosensitive glasses emphasized a synergy between photo-induced silver clusters and trivalentlanthanides. Indeed, a luminescence exaltation associated to the europium emission is measured.

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Ce travail est consacré au développement par voie sol-gel de fluorures ALnF4 (A=Li, Na et Ln= Y, Gd) et de composites SiO2/LiGdF4 activés par les ions Eu3+. Le passage par un état sol a permis d'élaborer des poudres et des films de ces matériaux luminescents. L'emploi de précurseurs moléculaires induit une répartition homogène des ions dopants dans les matrices évitant la formation d'agrégats. Plusieurs techniques expérimentales (DRX, IR et Raman, EXAFS, RMN, RPE, MEB et MET) ont été utilisées pour caractériser les propriétés structurales et morphologiques. Elles ont permis de définir les paramètres de synthèse et les traitements thermiques appropriés à l'obtention de phases pures. Les propriétés optiques des poudres ont été étudiées après excitation dans l'UV pour souligner l'efficacité du procédé sol-gel à produire des matériaux optiques de qualité et sous excitation VUV afin d'évaluer leurs capacités à être utilisés comme luminophores quantiques

Die Verfügbarkeit von Metallen in der Geo- und Biosphäre wird durch deren chemische Form, die Speziation, bestimmt. Zur Analyse der Speziation gibt es eine Vielzahl von Techniken. Für spektroskopische Methoden sind untersuchbare Konzentrationsbereiche unter anderem durch entsprechende Detektionsgrenzen eingeschränkt. Vor allem für niedrige Konzentrationen (< 10 µM), wie sie für viele natürliche Systeme von Bedeutung sind, ist die Lumineszenzspektroskopie ein geeignetes Werkzeug. Die Zerlegung spektroskopischer Daten von komplexen Systemen stellt eine zusätzliche Herausforderung dar. Zur Extraktion spektraler Informationen individueller chemischer Spezies werden moderne mathematische Verfahren verwendet. Die so erhaltene spektroskopische Charakterisierung kann zur strukturellen und thermodynamischen Interpretation genutzt werden. In dieser Arbeit wurde die parallele Faktoranalyse (PARAFAC) zur Auswertung spektroskopischer Datensätze genutzt. Diese Technik wurde hier erstmals auf Uranyl(VI)-Systeme angewendet, wodurch eine umfassende lumineszenzspektroskopische Charakterisierung der Uranyl(VI)-Hydrolyse generiert wurde. Zusätzlich wurde der bestehende PARAFAC-Algorithmus (N-way Toolbox) erweitert. Damit wird die Zerlegung auf chemisch interpretierbare Ergebnisse beschränkt und eine direkte Extraktion thermodynamischer Daten ermöglicht. Für die mononuklearen Hydrolysespezies konnten korrigierte Komplexstabilitätskonstanten vorgeschlagen werden, wodurch entsprechende Speziationsrechnungen belastbarer werden. Die extrahierten spektralen Eigenschaften einzelner Spezies wurden anschließend sorgfältig analysiert. Dazu wurden quantenmechanische sowie semiempirische Ansätze genutzt. Neben einerValidierung der angenommenen Speziesbezeichnung wurde dadurch erstmals eine fundierte lumineszenzspektroskopische Signal-Struktur-Beziehung für die Uranyl(VI)-Hydrolyse generiert. Die entwickelten Algorithmen wurden im Rahmen der Arbeit auf komplexere Systeme des Uranyl(VI) und Europium(III) übertragen und deren Gültigkeit nachgewiesen. So konnten neue Erkenntnisse zur Lumineszenzlöschung des Uranyl(VI)-Ions und der Europium(III)-Hydrolyse gewonnen werden. Zudem wurde eine Strategie zur einfachen und akkuraten Bestimmung der Anzahl von Bindungsstellen am Beispiel des Proteins Calmodulin vorgestellt. Der aufgezeigte breite Anwendungsbereich wird zusätzlich durch die erfolgreiche Übertragung der SpecConst-Erweiterung auf andere spektroskopische Techniken (am Beispiel der UV-vis Spektroskopie) erweitert. Die vorgestellten Werkzeuge verbessern die Auswertung spektroskopischer Daten und erweitern das damit verbundene Verständnis komplexer umweltrelevanter Systeme.

This thesis describes investigations into the optical and device design of organic light-emitting diodes (OLEDs) with the aim of exploring the factors controlling the spatial emission pattern of OLEDs and developing novel OLEDs with directional emission by applying wavelength-scale photonic microstructure. The development of directional OLEDs was broken down into two steps: the development of efficient narrow linewidth OLEDs and the integration of wavelength-scale photonic microstructures into narrow linewidth OLEDs. The narrow linewidth OLEDs were developed using europium (Eu) complexes. The electrical optimisation of solution-processed Eu-based OLEDs using commercially available materials was investigated. The optimised Eu-based OLEDs gave an external quantum efficiency of 4.3% at a display brightness of 100 cd/m². To our knowledge, this is the highest efficiency reported for solution-processed Eu-based OLED devices, and the efficiency roll-off has been reduced compared with other reported references. Photonic microstructures were applied to develop directional OLEDs using the efficient Eu-based OLEDs. Two contrasting strategies were used. One was to embed photonic microstructures into Eu-based OLEDs, the other was to couple photonic microstructures externally onto the devices. The microstructured devices developed by the former strategy boosted the emitted power in desired angles in both s- and p-polarisations and doubled the fraction of emission in an angle range of 4⁰. The devices developed by the external coupling strategy achieved even higher directionality and the out-coupled emission was a confined beam with easy control of beam steering. Around 90% of the emitted power was confined in an angular range of 20⁰ in the detection plane. The optical properties can be optimised independently without compromising the electrical properties of devices, which gives major advantages in terms of effectiveness and versatility. Optical models were also developed to investigate the out-coupling mechanism of various trapped modes and develop OLEDs with stronger directionality.

O presente trabalho aborda a síntese e caracterização de complexos benzenotricarboxilatos de íons Eu3+, Gd3+ e Tb3+, com o intuito de investigar suas características químicas e estruturais e correlacioná-las com as propriedades fotoluminescentes. Os complexos benzenotricarboxilato [TR(BTC)(H2O)n] foram sintetizados em solução aquosa, e apresentaram-se na forma de pós brancos, não-higroscópicos e insolúveis em solventes polares ou apolares. Os complexos com o ligante EMA se mostraram isomórficos e com grau de hidratação igual a dois. Os complexos com o ligante TLA também apresentaram isomorfismo, mas com estrutura cristalina diferente da dos complexos com os outros ligantes. Os complexos [Eu(TMA)(H2O)6] e [Gd(TMA)(H2O)6] apresentaram a mesma estrutura cristalina; entretanto, o complexo [Tb(TMA)] se mostrou anidro, o que foi confirmado pela termoanálise. Os espectros de absorção na região do invravermelho dos complexos evidenciaram que os ligantes BTC3- se coordenam aos íons TR3+ através dos grupos carboxilato desprotonados. Os espectros de fosforescência dos complexos [Gd(BTC)(H2O)n] exibem uma banda larga característica da emissão de cor azul dos ligantes BTC3- (c.a. 450 nm); as medidas das energias dos estados tripleto T1 dos ligantes mostraram que as energias dos estados variam de 25100 a 25700 cm-1, energia que é superior às dos níveis emissores 5D0 e 5D4 dos íons Eu3+ e Tb3+, respectivamente. A eficiente transferência de energia ligante-TR3+ (TR3+ = Eu3+ e Tb3+) nos complexos é comprovada pelos seus espectros de excitação (a banda de excitação do ligante apresenta alta intensidade, com máximo em c.a. 295 nm) e de emissão (não apresentam a banda de fosforescência do ligante, mas sim as transições características dos íons TR3+). Os espectros de emissão dos complexos [Tb(BTC)(H2O)n] evidenciaram a intensa luminescência de cor verde destes complexos, especialmente do complexo anidro [Tb(TMA)], que apresenta a grande vantagem de não sofrer supressão de luminescência causada pelos níveis vibracionais intermediários da água. Os espectros de luminescência dos complexos [Eu(BTC)(H2O)n] apresentam bandas desdobradas em picos finos bem definidos, o que significa que os íons Eu3+ nos complexos se encontram em sítios de simetria bem definida, corroborando o caráter cristalino indicados pelos difratogramas de raios X. Dentre os complexos [TR(BTC)(H2O)n], os maiores tempos de vida dos estados emissores correspondem aos estados T1 dos ligantes BTC3- nos complexos com o íon Gd3+ (entre 7,386 e 12,025 ms), seguidos pelo nível 5D4 do íon Tb3+ (entre 0,712 e 1,265) e por fim pelo nível 5D0 do íon Eu3+ (entre 0,253 e 0,630). Os complexos [Eu(BTC)(H2O)n] ainda apresentaram valores de eficiência quântica entre 12 e 24% Este valor decresce com o aumento do número de moléculas de água do sistema, evidenciando o seu caráter supressor de luminescência. Os complexos [TR(BTC)(H2O)n] mostram-se promissores para serem aplicados como marcadores ópticos, camadas emissoras em dispositivos eletroluminescentes e no desenvolvimento de fluoroimunoensaios, devido: i) ao caráter monocromático das emissões dos complexos com Eu3+ e Tb3+; ii) à elevada intensidade luminescente dos complexos [Tb(BTC)(H2O)n]; e iii) às emissões nas três cores primárias apresentadas por estes complexos, dentre os quais os complexos de Eu3+ e Tb3+ se mostraram bons Dispositivos Moleculares Conversores de Luz (DMCLs) / This work reports the synthesis and characterization of Eu3+, Gd3+ and Tb3+ benzenetricarboxylate complexes and the correlation of their structural and chemical characteristics with their photoluminescent properties. The benzenetricarboxylate complexes [TR(BTC)(H2O)n] were prepared in aqueous solution, and were obtained in the form of white, insoluble and non-hygroscopic powders. The [TR(EMA)(H2O)2] complexes presents isomorphism among them as as the [TR(TLA)(H2O)4] complexes. The thermoanalysis curves showed that the [Eu(TMA)(H2O)6] and [Gd(TMA)(H2O)6] complexes have the same crystalline structure. However, the [Tb(TMA)] complex is anhydrous. The IR spectra of the [TR(BTC)(H2O)n] complexes confirm that the BTC3- ligands are coordinated to the TR3+ ions through the carboxylate groups. The phosphorescence spectra of [Gd(BTC)(H2O)n] complexes exhibit a broad and characteristic emission band of the BTC3- ligands (c.a. 450 nm); the mensure of the ligands T1 states indicated that the T1 state energies varies between 25100 and 25700 cm-1, which is highest than 5D0 and 5D4 states of Eu3+ and Tb3+ ions, respectively. The efficiency of the ligand-TR3+ energy transfer in the [Eu(BTC)(H2O)n] and [Tb(BTC)(H2O)n] complexes is confirmed by their spectra of excitation (high intensity of the ligand excitation band, c.a. 295 nm) and emission (they have no ligand phosphorescence band, but the characteristics emission bands of TR3+ ions). The emission spectra of the [Tb(BTC)(H2O)n] complexes exhibit their highly intense green luminescence, specially to the anhydrous [Tb(TMA)] complex, that present the advantage of not undergoing the luminescence suppression effect caused by coupling with the intermediary vibrational levels of the water molecules. The luminescence spectra of [Eu(BTC)(H2O)n] complexes presents non-degenerated emission bands in thin and well defined peaks, indicating that the Eu3+ ions are in chemical environment with well defined symmetry, confirming the crystalline character indicated by the X-rays diffractograms. The longest emission lifetimes (between 7,386 and 12,025 ms) of the [TR(BTC)(H2O)n] complexes were found with the Gd3+ complexes, followed by the Tb3+ complexes (0,712 to 1,265 ms), and the Eu3+ complexes (0,253 to 0,630 ms). The [Eu(BTC)(H2O)n] complexes presented quantum efficiencies between 12 and 24%. This value decreases with the growth of the hydration degree of the complex. The [TR(BTC)(H2O)n] complexes are promising candidates for applications such as optical markers, emission layers in electroluminescent devices and in the developing of fluoroimmunoassays due to: i) the monochromatic character of the Eu3+ and Tb3+ complexes emissions; ii) the high luminescence intensities of the [Tb(BTC)(H2O)n] complexes; and iii) the emissions in the three primary colors presented by this complexes. Moreover, the Eu3+ and Tb3+ complexes are efficient light conversion molecular devices (LCMDs)

A investigação das propriedades ópticas e sua relação com as propriedades magnéticas dos semicondutores é de grande interesse para a comunidade científica, em virtude da enorme demanda por novas tecnologias e funcionalidades que podem surgir dessas pesquisas. Os calcógenos de európio são semicondutores intrinsecamente magnéticos, transparentes na região visível do espectro eletromagnético e integráveis em matrizes de silício e nitreto de gálio, sendo assim fortes candidatos a aplicações tecnológicas envolvendo magnetismo e óptica. Neste trabalho são investigados os espectros de absorção e fotoluminescência dos calcógenos de európio, com base no modelo 4f -> 5d(\'t IND. 2g\') da transição óptica de dipolo elétrico, o qual mostrou-se totalmente adequado para a descrição da absorção óptica nos calcógenos de európio em função do campo magnético aplicado, explicando a presença de linhas de absorção estreitas e dicróicas nos espectros em campo alto e a forma larga dos espectros de absorção em campo nulo. Nos espectros de fotoluminescência do EuTe, entretanto, foram detectados estados eletrônicos não contemplados pelo modelo 4f -> 5d(\'t IND. 2g\') , em especial uma banda de emissão denominada \'MX IND. 0\', acoplada a modos vibracionais da rede. Uma linha zero-fônon correspondente a uma transição que não produz fônons pôde ser bem definida e a partir do deslocamento dessa linha em função do campo magnético foi possível detectar inequivocamente a formação de polarons magnéticos no EuTe pela primeira vez; o raio polarônico foi estimado como R = 3.6a, onde a é o parâmetro de rede e a energia de ligação desse polaron foi estimada em \'E IND. p\' = 45 meV, um resultado que foi confirmado através de medidas do deslocamento da linha zero-fônon em função da temperatura. Adicionalmente procurou-se identificar o estado eletrônico associado à emissão \'MX IND. 0\': a partir de medidas da intensidade da fotoluminescência em função da potência de excitação foi possível sugerir que a emissão \'MX IND. 0\' provem de estados eletrônicos ligados a defeitos da rede e foi possível estimar a concentração desses defeitos como menor que 0.1 ppm. / Investigation of optical properties and their relation to magnetic properties of semiconductors is of great interest to scientific community, due to the large demand for new technologies and features that can arise from these studies. Europium chalcogenides are intrinsically magnetic semiconductors, transparent in the visible region of electromagnetic spectrum and integrable into silicon and gallium nitride matrices, beeing strong candidates for technological applications involving magnetism and optics. The present study investigates absorption and photoluminescence spectra of europium chalcogenides, based on the 4f -> 5d(t2g) model of the electric dipole optical transition, which proved to be entirely appropriate to describe polarized optical absorption in europium chalcogenides as a function of magnetic field, explaining the presence of narrow dichroic lines at high fields and the broad shape of the zero-field absorption spectrum. However, in photoluminescence spectra of EuTe, electronic states not covered by the 4f -> 5d(t2g) model were detected, in particular an emission band labeled MX0, which is coupled to vibrational modes of the lattice. A transition without production of phonons, corresponding to a zero-phonon line, could be well resolved and from the displacement of the zero-phonon line as a function of magnetic field the formation of magnetic polarons in EuTe could be detected unambiguously for the first time. The polaronic radius is estimated as R = 3:6a, where a is the lattice parameter, and the polaron binding energy is estimated as Ep = 45 meV, a result that was confirmed by measurements of zero-phonon line displacement as a function of temperature. Additionally, we sought to identify the electronic state associated with MX0 emission: from measurements of the photoluminescence intensity as a function of excitation power, it was possible to suggest that MX0 emission comes from an electronic state coupled to lattice defects of low concentration, which we estimate to be of less than 0.1 ppm.

Polímeros dopados com complexos de terras raras são materiais vantajosos na produção de filmes para várias aplicações no campo da luminescência. Neste estudo de polímeros luminescentes obtidos a partir de polímeros como o policarbonato (PC) e o poli(9-vinilcarbazol) (PVK), os filmes dopados com o complexo diaquatris (tenoiltrifluoroacetonato) de európio (III) [Eu(tta)3(H2O)2] foram preparados e suas propriedades térmicas e luminescentes no estado sólido relatadas. O comportamento térmico foi investigado por uso de calorimetria diferencial exploratória (DSC) e análise termogravimétrica (TGA). Devido à adição de complexo terras raras [Eu(tta)3(H2O)2] na matriz de PC e PVK, foram observadas alterações no comportamento térmico, relativo à transição vítrea e estabilidade térmica. As emissões finas características do íon Eu3+ decorrentes das transições 5DO &rarr; 7FJ (J = 0-4) indicaram a incorporação de íons de Eu3+ nos polímeros. Os filmes mostraram que a intensidade de emissão luminescente aumenta com o aumento da concentração de terras raras na matriz polimérica acompanhado por uma diminuição na estabilidade térmica. / Polymers doped with rare earth complexes are advantaged in film production for many applications in the luminescent field. In this study luminescent polymer obtained from polycarbonate (PC) and poly (9-vinylcarbazole) films doped with diaquatris (thenoyltrifluoroacetonate) europium (III) complex [Eu(tta)3(H2O)2] were prepared and their calorimetric and luminescent properties in the solid state are reported. The thermal behavior was investigated by differential scannig calorimetry (DSC) and thermogravimetry analysis (TGA). Due of the addition of rare earth [Eu(tta)3(H2O)2] into PC and PVK matrices, changes were observed in the thermal behavior concerning the glass transition and thermal stability. Characteristic broadened narrow bands arising from de 5DO &rarr; 7FJ transitions (J = 0-4) of Eu3+ ion indicate the incorporation of the Eu3+ ions into those polymers. The luminescent films show enhancement emission intensity with an increase in the rare earth concentration in polymeric matrix accompanied by decrease in thermal stability.