An aim of this work is a research of a deposition process of indium tin oxide by plasma assisted methods. The thesis deals with plasma diagnostics, e.g. Langmuir probe diagnostics and optical emission spectroscopy, as well as describes experiments of film deposition including their diagnostics, e.g. absorption spectroscopy, X-ray diffractometry and atomic force microscopy.

Made available in DSpace on 2016-06-02T20:15:21Z (GMT). No. of bitstreams: 1 3005.pdf: 10668736 bytes, checksum: 8ec8cb21968edc4feb09cb7616b0e9b2 (MD5) Previous issue date: 2010-05-07 / Universidade Federal de Minas Gerais / The structural and transport features of oxide nanostructures synthesized by a vapour phase aproach: the VLS and VS methods were investigated in this work. ITO and In2O3 nanowires were characterized by using XRD, HRTEM and FEG-SEM techniques. Both nanostructures were found to be body-centered cubic (bixbyite, point group Ia3) single crystals with a well defined growth direction. Raman spectroscopy was used in order to study the nanowires composition, crystalline character and the role of tin atoms in the In2O3 lattice (ITO) was studied as well. The influence of the structural disorder induced by doping was pointed as the main cause of the break of the selection rules in ITO and it was promptly recognized in the Raman spectrum. The metallic character observed in In2O3 micrometric wires was assigned to the electron-phonon scattering in agreement with the Bloch-Grüneisen theory. ITO samples with different sizes were analysed in the framework of the Bloch-Grüneisen theory and at high temperatures (T > 77 K) they were found to present a typical metallic character. It was observed at low temperatures (T < 77 K) and in small samples a negative temperature coefficient of resistance which is an evidence that quantum interference processes are present. A weak localized character was found in these samples as detected in magnetoresistance measurements. The electron s phase break was associated to the electronelectron scattering (T < 77 K) and the electron-phonon scattering (T > 77 K). The transport measurements in one-nanowire based FET provided data on the electron s mobility and density. Tin oxide nanobelts were also studied and their structural and electrical characterizations were obtained. In this case the association of several structural measurements provided that the samples are rutile-like single crystals (point group P42/mnm) grown by the VS mechanism. The transport measurements provided data on the nanobelts gap energy (3.8 eV) and on the transport mechanisms acting in different temperature ranges. An activated-like process and the variable range hopping were found to be present in different temperature range and additionally the localization length was determined. The influence of additional levels inside the gap caused by oxygen vacancies was studied by performing light and atmosphere-dependent experiments and as a result a photo-activated character was detected. Thermally stimulated current measurements provided evidence that only one level associated to the oxygen vacancies at 1.8 eV seems to contribute to the transport in SnO2 nanobelts. Triclinic single crystalline nanobelts were identified as the Sn3O4 phase and were analyzed by transport measurements. The samples were wide band gap semiconductors and the role of oxygen vacancies was identified by using PL and PC measurements. The semiconductor behavior was confirmed by the electron transport data, which pointed to the variable range hopping process as the main conduction mechanism (55 K < T < 398 K) and data on localization length and on the hopping distance were obtained. The presence of additional levels due to oxygen vacancies and tin interstitials was recognized in the samples by performing photo-activated and thermally stimulated current measurements. / Neste trabalho foram investigadas características estruturais e de transporte eletrônico em nanoestruturas óxidas sintetizadas por métodos baseados em fase de vapor: os métodos VLS e VS. Amostras de In2O3 e ITO foram caracterizadas quanto às suas características estruturais usando-se técnicas experimentais como XRD, HRTEM e FEG-SEM e comprovou-se que são monocristais cúbicos de corpo centrado (bixbyite) pertencentes ao grupo puntual Ia3 com direção preferencial de crescimento bem definida. A espectroscopia Raman foi utilizada como ferramenta fundamental para o estudo da composição destes materiais, confirmando a fase, o caráter monocristalino bem como a presença de dopantes na estrutura do In2O3 como no caso do ITO. Estudou-se ainda a influência da desordem estrutural causada pela dopagem nas estruturas já que esta se reflete diretamente em uma quebra na regra de seleção do material e portanto, no espectro Raman. O estudo dos mecanismos de transporte eletrônico em microfios de In2O3 mostrou uma característica essencialmente metálica nestes materiais, comprovada pela identificação do espalhamento elétron-fônon (teoria de Bloch-Grüneisen) como a principal fonte de espalhamento. Amostras de ITO com diferentes tamanhos também foram estudadas e observou-se, acima de 77 K, o aumento da resistência com o aumento da temperatura também caracterizado pela interação elétron-fônon. A observação de um coeficiente negativo de temperatura da resistência observado na amostra nanométrica e em baixas temperaturas aponta para a presença de processos quânticos de interferência originados principalmente da redução da dimensionalidade da amostra. De fato, a aplicação de um campo magnético mostrou a supressão desse comportamento em função da temperatura, comprovando assim que a chamada localização fraca encontra-se presente no nanofio de ITO. Nesse caso, a destruição da fase do elétron foi associada ao espalhamento elétron-elétron (T < 77 K) e ao espalhamento elétron-fônon (T > 77 K). O uso das referidas amostras como transistores de efeito de campo permitiu ainda a obtenção de parâmetros importantes como a mobilidade e a densidade de portadores nas amostras. Nanofitas de SnO2 também foram estudadas e suas propriedades estruturais e de transporte eletrônico foram obtidas. Nesse caso encontrou-se através de técnicas de medida variadas que as amostras são monocristais com estrutura do tipo rutila (grupo puntual P42/mnm) sintetizadas pelo método VS. Diferentes experimentos de transporte eletrônico permitiram a determinação do gap de energia deste material em 3.8 eV e ainda permitiram identificar a presença de diferentes mecanismos de transporte atuando em intervalos de temperatura bem determinados. De fato observou-se a transição de um comportamento de ativação térmica para um comportamento localizado e também ativado por fônons, o hopping donde se determinou o comprimento de localização eletrônico. A presença de níveis adicionais ao gap de energia foi estudada através de experimentos feitos em diferentes atmosferas e sob ação de luz ultravioleta visando explorar o caráter foto-ativado detectado nas amostras. Foi observado de medidas termicamente estimuladas a emissão termiônica de portadores através dos contatos elétricos o que indica que o único nível que parece contribuir com portadores livres nas nanofitas de SnO2 é aquele detectado em 1.8 eV. Amostras monocristalinas com estrutura triclínica, com morfologia de fita e cuja fase foi identificada como sendo Sn3O4 foram também investigadas. A presença de vacâncias de oxigênio e de um gap largo de energia foram observadas através de experimentos de PL e PC. O hopping foi identificado em um grande intervalo de temperaturas (55 K < T < 398 K) como o principal mecanismo de transporte eletrônico observado nas amostras o que comprova a presença de localização e também indica que as amostras se comportam como um semicondutor. Adicionalmente, parâmetros como o comprimento de localização e a distância de pulo dos elétrons foram calculadas. A presença de vacâncias de oxigênio nestas amostras foi ainda estudada através de medidas foto-ativadas pela luz ultravioleta e em diferentes atmosferas de medida, e também por experimentos de TSC donde obteve-se evidências adicionais sobre a presença de outras fontes de elétrons livres como vacâncias superficiais ou interstícios de estanho, contribuindo para o transporte nestas amostras.

In this study, we used UV-ozone Ar sputtering, X-ray photoelectron and ultra-violet photoelectron spectroscopies and sputtering based depositions of RuO2 and Se nano-layers on indium tin oxides (ITOs). We elucidated the effect of Ar sputtering on the composition and chemistry of Sn rich ITO surface. We demonstrated that while a combination of UV-ozone radiation and Ar sputtering removes most of the hydrocarbons responsible for degrading the work function of ITO, it also removes significant amount of the segregated SN at the ITO surface that's responsible for its reasonable work function of 4.7eV. We also demonstrated for the first time that sputtering cleaning ITO surface leads to the reduction of the charge state of Sn from Sn4+ to Sn2+ that adds to the degradation of the work function. For the nano-layers coverage of ITO studies, we evaluated both RuO2 and Se. For RuO2 coated ITO, XPS showed the formation of a Ru-Sn-O ternary oxide. The RuO2 nano-layer reduced the oxidation state of Sn in the Sn-rich surface of ITO from +4 to +2. The best work function obtained for this system is 4.98eV, raising the effective work function of ITO by more than 0.5 eV. For the Se coated ITO studies, a systematic study of the dependence of the effective work function on the thickness of Se overage and its chemistry at the Se/ITO interface was undertaken. XPS showed that Se reacts with Sn at the Sn-rich surface of ITO determined the presence of both negative and positive oxidation state of Se at the Se/ITO interface. The Se also reduced the oxidation state of Sn from Sn4+ to Sn2+ in the Sn-rich ITO surface. The highest effective work function obtained for this system is 5.06eV. A combination of RuO2/Se nanoscale coating of optimally cleaned ITO would be a good alternative for device applications that would provide work function tuning in addition to their potential ability to act as interface stabilizers and a barrier to reaction and inter-diffusion at ITO/active layers interfaces responsible for long term stability of devices and especially organic solar cells and organic light emitting diodes.

Introduction : Les dyschromies cutanées en mosaïque ont fait suspecter de longue date l’implication d’un mosaïcisme génétique sous-jacent. Ces évènements post-zygotiques sont cependant difficilement détectables par les techniques conventionnelles. Ainsi, les bases génétiques des dyschromies en mosaïque étaient restées mal connues. Matériel et méthodes : la cohorte M.U.S.T.A.R.D rassemble des échantillons d’ADN de biopsies cutanées de patients porteurs d’un mosaïcisme pigmentaire. Après une analyse phénotypique spécialisée, ces échantillons sont étudiés en séquençage à forte profondeur, d’exome (ES) en trio, ou ciblé. Les données sont analysées à l’aide d’un pipeline dédié, permettant la détection de variations ponctuelles en mosaïque (mSNV) mais également de diverses anomalies chromosomiques en mosaïque. Résultats : De 2013 à 2019, 101 patients ont été inclus. Un ES a été réalisé pour 56 patients, identifiant un mSNV chez 12 patients, dans 7 gènes dont 4 nouveaux (RHOA, DOCK1, GNA13, TFE3), et une anomalie chromosomique chez 17 patients. Une étude ciblée de ces gènes chez 40 autres patients était positive pour 17, soit un rendement diagnostique global à 55% (46/84). Conclusion : Ce travail illustre l’importance d’une approche bioinformatique polyvalente, combinée à une expertise clinique, pour la détermination des causes génétiques des dyschromies cutanées en mosaïque. Il a également mis en évidence le rôle de la voie de signalisation dépendant des Rho GTPases, faisant progresser notre compréhension de la physiopathologie des dyschromies en mosaïque, une étape nécessaire à l’amélioration de la prise en charge de ces patients porteurs de maladies rares et complexes. / Introduction: Mosaic cutaneous dyschromia is strongly evocative of an underlying genetic mosaicism. These post-zygotic events are challenging for conventional diagnostic tools. Thus, genetic basis of mosaic cutaneous dyschromia still remained poorly understood. Materials and Methods: The M.U.S.T.A.R.D. cohort gathers DNA from skin biopsies of patients with mosaic cutaneous dyschromia. After a specialised phenotype analysis, they are referred to either trio exome sequencing (ES) at 200X, or targeted ultra-deep sequencing (60,000X) of candidate genes. Data are analysed with a tailored pipeline, allowing detection of both low-rate nucleotidic variations or chromosomal events. Results: From 2013 to 2019, 101 patients were included. ES was performed for 56, with identification of mosaic SNV in 12 patients in 7 new genes, including 4 new genes (RHOA, DOCK1, GNA13, TFE3), and mosaic chromosomal anomalies in 17 patients. A targeted sequencing of these genes was performed for 40 more patients, with a confirmed mosaic SNV in 17, and a global diagnostic yield of 55% (46/84). Conclusion: This work highlights the importance of a versatile bioinformatic approach combined to a clinical expertise, to decipher the chromosomal and molecular aetiologies of developmental anomalies with mosaic cutaneous dyschromia. It also pinpoints the role of the Rho GTPase pathway, which will help enhancing our understanding of mosaic cutaneous dyschromia, and may ultimately result in better patients’ care.

In der vorliegenden Arbeit wird der reaktive ITO-Abscheidprozess unter Verwendung metallischer In:Sn-Targets eingehend untersucht. Die Schichtabscheidung erfolgt am symmetrisch bipolar gepulstem Dual-Magnetron sowohl auf ruhende als auch bewegte Substrate. Die Arbeit umfasst zwei Teilgebiete. Einerseits wurde der dynamische ITO-Abscheideprozess an einer industrienahen Versuchsanlage umfassend charakterisiert und anhand seiner physikalischen Parameter erfolgreich an eine industrielle Beschichtungsanlage überführt. Andererseits fanden statische Beschichtungen statt. Diese ermöglichen die Analyse der lateralen Verteilung der funktionellen Schichteigenschaften. Dadurch konnte eine Korrelation zu den lateralen Verteilungen der gemessenen Plasmaparameter herausgearbeitet werden.

A key to solar cells with lower environmental impact is higher efficiency and reduced material usages. Bifacial solar cells may have a higher efficiency as light can enter from two directions and tandem solar cells may use a larger part of the incoming solar spectrum, increasing the efficiency. However, both these applications require transparent and conducting contacts. This thesis aimed to investigate how suitable the transparent conductive oxides aluminum doped zinc oxide (AZO) and indium doped tin oxide (ITO) are as contacts in bifacial CIGS cells or CIGS/Silicon tandem cells. The contacts must remain stable when CIGS is deposited on top of it, meaning that they have to endure first 500°C and then 600°C in combination with copper, indium, gallium and selenium vapours. A thin layer of AZO topped with ITO and pure ITO films of different thicknesses were deposited by RF- and DC-sputtering, varying the oxygen flow. Opto-electrical characterization showed that the transparency in the infrared was balanced against high conductivity due to a shift in the plasmon peak's position. No great difference was seen between pure ITO samples and AZO/ITO samples, so only the first where further processed. The ITO films were annealed to 500°C in the CIGS deposition chamber, exposed to selenium vapour. The films' sheet resistances dropped drastically, which was mainly attributed to activation of tin donors. ITO produced with low oxygen flows also appeared more crystalline according to x-ray diffraction measurements. Photon absorption in the ITO was used to estimate the current loss in bifacial and tandem applications and graphs with current loss and sheet resistance can be used to select an ITO deposition process. Commercial ITO was exposed to 100s of the CIGS deposition process but only during selenium and gallium vapour. A layer of gallium selenide could be identified on the surface, but the ITO appeared to remain stable. Sodium fluoride pre deposition treatment lowered the samples absorption for all wavelengths compared to non-treated samples.

No description available.

[pt] Este trabalho examina o fenômeno de retomada da estética da transparência na arquitetura a partir dos anos 1990, depois de anos de latência desde a substituição da linguagem moderna, abstrata e etérea, das primeiras vanguardas por outra que expressasse aspectos regionais e fenomenológicos. Tal retomada estaria associada ao desenvolvimento das novas tecnologias digitais e à realidade estruturada segundo a dinâmica do capitalismo pós-industrial. Estas configurariam uma estrutura urbana desmaterializada, instável e independente da construção física. Tais mudanças teriam tornado obsoletos os paradigmas da solidez, funcionalidade e beleza, herdados da tradição clássica. A tendência ao desaparecimento das qualidades substanciais da arquitetura e a consequente perda dos referenciais fenomenológicos nos recolocou a questão do habitar. A estética da transparência estaria inicialmente associada à concepção iluminista, que pressupunha a clareza dos objetos e a emancipação do sujeito, mas se desdobrará no sentido da ambiguidade em função da ruptura com o conceito de espaço euclidiano, ocorrida em torno de 1910. Tal ruptura teria sido promovida tanto pelas descobertas científicas que unificavam as dimensões de tempo e espaço, quanto pela disseminação de imagens aéreas cinematográficas. As imagens retratavam o espaço topológico e apresentavam a realidade sob a ordem da fragmentação e da perda de perspectiva. A concepção de espaço topológico foi também associada aos sentimentos de angústia e desenraizamento, experimentados pelo homem moderno. A expressão dessa patologia nas artes de vanguarda será criticada por fomentar a desarticulação do engajamento político através de um método que promoveria a perda de visão da totalidade do real. Tal método teria sido desenvolvido por Wilhelm Worringer a partir da noção de Vontade de Arte, expressa no impulso para abstração, este relativo ao conceito do espaço topológico. Este trabalho verificou que tal mudança na concepção de espaço levará à reformulação do conceito de transparência de literal para fenomênica, caracterizada nas artes pela representação de múltiplos pontos de vista, da interpenetração espacial e da perda de profundidade. A transparência fenomênica será associada contemporaneamente ao espaço paranoico, que viria sendo desenvolvido com a contribuição da tecnologia digital em termos espaciais e da mutação dos corpos segundo sua conexão com a realidade virtual. A tecnologia cibernética determinaria um novo tipo de expressão da alienação e o desdobramento da noção de transparência, que qualificamos como abjeta. A transparência foi associada pelos primeiros modernos à expressão de japonidade na arquitetura, cuja essência o desenvolvimento da história tratou de contrariar ao evidenciar seu modo interativo. Verificamos neste trabalho algumas das contribuições japonesas em função de suas qualidades locais. Tomamos o edifício para a Midiateca Sendai (2001) de Toyo Ito como objeto de estudo. A Midiateca levaria ao extremo a noção de transparência ao estendê-la das fachadas às estruturas vazadas, pensadas como expressão do espaço puro na linguagem abstrata moderna. Seu programa seria multifuncional e aberto a mudanças, considerando a participação da comunidade e dos demais membros institucionais desde o processo de projeto. Esta obra responderia tanto à questão da autonomia artística quanto à da perda de função social, associadas ao esteticismo das vanguardas modernas. / [en] This dissertation examines the phenomenon of the revival of the aesthetics of transparency in architecture since the 1990s, when the expression of regional and phenomenological aspects has been replaced by a modern, abstract and ethereal language. This revival has been associated with the development of new digital technologies and with post-industrial capitalism, producing dematerialized and unstable urban structures which are independent of their physical construction. Such changes would have rendered the classical tradition paradigms of solidity, functionality and beauty obsolete. The tendency towards the disappearance of the substantial qualities of architecture and the consequent loss of phenomenological references has brought us back to the question of dwelling. The aesthetics of transparency has been associated with the Enlightenment and it presupposes clarity of objects and emancipation of the subject. However, around 1910, it produced a sense of ambiguity due to the rupture with the concept of Euclidean space. Such a rupture may have been promoted both by the scientific discoveries that unified the dimensions of time and space, and by the dissemination of cinematographic aerial images. These images portrayed the topological space and presented a fragmented reality without perspective. The conception of topological space has also been associated with the feelings of anguish and uprooting of the modern human being. The expression of this pathology in the avant-garde arts has been criticized for fomenting the disarticulation of the political engagement through a method that would promote the loss of a complete vision of reality. Wilhelm Worringer has allegedly developed the method from the notion of the Will to Art expressed as an urge to abstraction, which is related to the concept of topological space. The present study verified that such a change in the conception of space leads to a literal and phenomenal reformulation of the concept of transparency, which is characterized in the arts by the representation of multiple points of view, spatial interpenetration and loss of depth. Phenomenal transparency is nowadays associated with a paranoid space, which is developed with the contribution of digital technology in spatial terms and the transformation of bodies according to their connection with virtual reality. Cybernetic technology may be determining a new kind of expression of alienation of the notion of transparency, which we consider to be abject. The early moderns have associated transparency with the expression of Japan-ness, which has been described as essentially interactive. Here we verify some of the Japanese contributions due to their local qualities. Our object of study is the Sendai Mediatheque (2001), by Toyo Ito. This building takes the notion of transparency to the extreme by extending it from the facades to the hollow structures, which is considered an expression of pure space in modern abstract language. Its program is multifunctional and open to change, and the community and other institutional members are involved with the project. Ito s work brings into question the artistic autonomy as well as the loss of social function, which is associated with the aestheticism of modern avant-gardes. / [de] Subjekts voraussetzte. Um 1910, wird es wird aber zweideutig aufgrund des Bruches mit dem Begriff des euklidischen Raums. Dieser Bruch wurde sowohl durch die wissenschaftliche Entdeckungen der Vereinheitlichung der Dimensionen von Zeit und Raum gefordert, , als auch durch die Verbreitung kinematografischer Luftbilder. Diese Bilder portratierten den topologischen Raum und prasentierten eine fragmentierte Realitat mit Perspektivverlust. Die Konzeption des topologischen Raums war auch mit den Gefuhlen der Angst und Entwurzelung des modernen Menschen verbunden. Der Ausdruck dieser Pathologie bei der kunstlerischen Avantgarde wird zur Forderung des Abbaus des politischen Engagements durch ein Verfahren kritisiert werden, die den Verlust des Sehvermogens der Gesamtheit der Wirklichkeit fordern wurden. Diese Methode soll von Wilhelm Worringer aus dem Begriff der Kunstwollen entwickelt worden sein. Sie ist durch den Abstraktionsdrang ausgedruckt, und ist auf den Begriff des topologischen Raumsbezogen. Diese Studie ergab, dass eine solche Anderung in der Gestaltung des Raumes auf die Neuformulierung des Konzepts der Transparenz von wortliches zu phanomenale fuhren wird, was in der Kunst durch mehrere Gesichtspunkte, raumlichen Dringen und Verlust der Tiefe gekennzeichnet ist. Phanomenale Transparenz wird gleichzeitig mit paranoidem Raum assoziiert, der mit dem Beitrag der digitalen Technologie in raumlicher Hinsicht und der Mutation von Korpern entsprechend ihrer Verbindung mit virtueller Realität entwickelt wird. Die kybernetische Technologie wurde einen neuen Ausdruck der Entfremdung und die Entfaltung des Begriffs der Transparenz bestimmen, was wir als abjekt bezeichnen. Transparenz wurde in der Modernitat mit Japan-heit verbunden. Ihr interaktiven Modus wurde in der Geschichte demonstriert. Wir uberprufen in dieser Arbeit einige der japanischen Beitrage mit ihren lokalen Qualitaten. Unser Untersuchungsobjekt ist das Gebaude fur die Mediathek in Sendai (2001), von Toyo Ito. Die Mediathek nimmt den Begriff der Transparenz zum Extrem, da ihre Fassaden sich an den hohlen Strukturen erweitert. Diese Strukturen sind ein Ausdruck des reinen Raumes in der modernen abstrakten Sprache. Die Mediathek ist multifunktional und veranderungsfahig, und die Gemeinschaft ist am Projekt beteiligt. Das Werk von Toyo Ito stellt in Frage die kunstlerische Autonomie als Verlust der sozialen Funktion entsprechen, die mit dem Asthetizismus der modernen Avantgarde verbunden ist.

Ce travail de thèse porte sur la modélisation, la fabrication et la caractérisation de Lasers à Cavité Verticale Emettant par la Surface (VCSEL) de grandes dimensions pour la manipulation de solitons de cavité, pour lesquels ces lasers permettraient une manipulation électrique plus souple de ces ondes stationnaires. Pour cela, il est nécessaire de disposer de structures à large zone d'émission uniforme (~100µm). Or, l'injection par électrode annulaire dans les VCSEL émettant par la surface entraîne une inhomogénéité rédhibitoire. Cette étude vise donc à proposer et évaluer des solutions technologiques innovantes pour atteindre une uniformité optimale dans ces dispositifs. Après une introduction dressant un état de l'art des solutions rapportées dans la littérature, nous présentons les travaux que nous avons menés sur la modélisation électrique des lasers pour évaluer les approches génériques de complexité croissante suivantes : l'ajout d'une couche d'étalement du courant en surface (électrode transparente en ITO) ; l'association de cette dernière à une barrière de potentiel (diode Zener) et la discrétisation de l'injection par création de zones localisées de conduction. L'optimisation des électrodes en ITO déposées sur GaAs, l'évaluation de l'apport d'une diode Zener ainsi que la mesure du contraste d'injection obtenu par gravure localisée en surface du composant sont ensuite détaillées. Suite à cette mise au point technologique, l'insertion des solutions que nous avons finalement retenues (gravures localisées et ITO) pour la réalisation de VCSEL est ensuite décrite. Enfin, les caractérisations électro-optiques des composants réalisés sont présentées; elles ont déjà permis d'obtenir des dispositifs de forme allongée émettant 50mW en continu à l'ambiante. Ces premiers résultats prometteurs ont cependant mis en évidence la nécessité d'améliorer encore les propriétés de l'interface ITO/GaAs. Ces solutions pourront alors être mises à profit pour l'application visée mai s également pour la génération de puissance ou encore la réalisation de VCSEL à cavité externe (VECSEL).

L'oxyde d'indium dopé à l'étain (ITO) présente une bonne transparence dans le visible<br />et une importante conductivité électrique. Ce travail est consacré à l'étude des performances<br />de films minces multicouches d'ITO obtenus par la voie sol-gel.<br />La microscopie électronique en transmission (MET) a permis d'analyser morphologie<br />et structure, et a mis en évidence pour la première fois la structure complexe de tels films solgel.<br />La MET et l'analyse par rétrodiffusion de particules α ont précisé la corrélation entre la<br />densité des multicouches, l'apparition de croûtes intermédiaires et la conductivité électrique<br />résultante.<br />Ce travail valide l'utilisation du recuit rapide pour la densification des films sol-gel en<br />comparaison avec un traitement classique.<br />Nous démontrons la potentialité de la voie sol-gel pour la croissance d'électrodes<br />d'ITO sur silicium poreux (SP). Les structures ITO/SP, pour lesquelles la photoluminescence<br />du SP est partiellement préservée, ont été étudiées en terme de diode Schottky.