A proposta deste trabalho é a produção de matrizes de nanotubos de dióxido de titânio seguindo os métodos de anodização eletroquímica de titânio estabelecidos da literatura. O objetivo central é a compreensão aprofundada das etapas do processo de crescimento dos nanotubos de TiO2, para posterior otimização de sua síntese visando as diferentes aplicações. Com este propósito foram realizados sistematicamente os seguintes estudos: das diferentes fases de crescimento dos nanotubos de TiO2, do efeito dos diferentes parâmetros de anodização na morfologia dos nanotubos e da reprodutibilidade dos processos. Visando as diferentes aplicações foram estudados métodos para obtenção de membranas autossustentadas e remoção de nanoresíduos. O método de camada sacrificial de fotoresiste positivo apresentou melhor resultado para remoção de nanoresíduos do topo dos nanotubos de TiO2 do que as demais técnicas. Por último, os arranjos obtidos com esta método foram aplicados na fabricação dos sensores de pH. / This work proposes the production of titania nanotubes arrays following the electrochemical anodization methods of a titanium sheet established in the literature. The main goal is a deep comprehension of the different TiO2 nanotubes growth stages for further optimization aiming the diverse applications. In this way the following systematic studies were performed: of the initial growth stages, of the effect of each anodization parameter on the nanotubes morphology and of the process reproducibility. In addition, methods for the production of self-sustained membranes as well as for obtaining a nanotube array surface free of nanoremnants were studied aiming the different applications. Positive photoresist bases sacrificial layer method presented a better result to eliminate nano-remnants on top of TiO2 nanotubes than other techniques. Finally, the nanotubes arrays obtained with this method were utilized for pH sensors fabrication.

A proposta deste trabalho é a produção de matrizes de nanotubos de dióxido de titânio seguindo os métodos de anodização eletroquímica de titânio estabelecidos da literatura. O objetivo central é a compreensão aprofundada das etapas do processo de crescimento dos nanotubos de TiO2, para posterior otimização de sua síntese visando as diferentes aplicações. Com este propósito foram realizados sistematicamente os seguintes estudos: das diferentes fases de crescimento dos nanotubos de TiO2, do efeito dos diferentes parâmetros de anodização na morfologia dos nanotubos e da reprodutibilidade dos processos. Visando as diferentes aplicações foram estudados métodos para obtenção de membranas autossustentadas e remoção de nanoresíduos. O método de camada sacrificial de fotoresiste positivo apresentou melhor resultado para remoção de nanoresíduos do topo dos nanotubos de TiO2 do que as demais técnicas. Por último, os arranjos obtidos com esta método foram aplicados na fabricação dos sensores de pH. / This work proposes the production of titania nanotubes arrays following the electrochemical anodization methods of a titanium sheet established in the literature. The main goal is a deep comprehension of the different TiO2 nanotubes growth stages for further optimization aiming the diverse applications. In this way the following systematic studies were performed: of the initial growth stages, of the effect of each anodization parameter on the nanotubes morphology and of the process reproducibility. In addition, methods for the production of self-sustained membranes as well as for obtaining a nanotube array surface free of nanoremnants were studied aiming the different applications. Positive photoresist bases sacrificial layer method presented a better result to eliminate nano-remnants on top of TiO2 nanotubes than other techniques. Finally, the nanotubes arrays obtained with this method were utilized for pH sensors fabrication.

Cette étude avait pour objectif de développer un nouveau support photocatalytique pour des applications potentielles dans le domaine du traitement des eaux. Le choix s'est porté sur les nanotubes d'oxyde de titane (TiO2) et l'étude a plus particulièrement porté sur l'optimisation de leurs propriétés photocatalytiques vis-à-vis de la l'oxydation de solution aqueuse de composés azotés. Les nanotubes de TiO2 ont été préparés par anodisation électrochimique en faisant varier le potentiel appliqué, la durée d'anodisation, le pH et la viscosité du milieu électrolytique (milieu aqueux ou milieu glycérol), ainsi que la nature du substrat sur lequel étaient déposés ces nanotubes. Une fois anodisés, ces nanotubes amorphes et se présentant sous forme sous-stœchiométrique (O/Ti <2) ont été recuits à différentes températures afin d'obtenir des phases de TiO2 variées (anatase, anatase/rutile). Au cours de ces différentes étapes, les différents nanotubes obtenus ont été caractérisés morphologiquement et structurellement par analyses par diffraction des rayons X (DRX) et par microscopie électronique à balayage (MEB).L'activité photocatalytique de ces différents matériaux a été déterminée à partir des rendements de photodégradation d'un composé modèle, la 4-nitroaniline. Là aussi, différents facteurs ont été étudiés, à savoir le pH du milieu réactionnel, le type de lampe UV et les durées d'irradiation.Les résultats montrent que les performances photocatalytiques des nanotubes de TiO2 les meilleures sont obtenues lorsqu'ils sont déposés sur substrat de Ti massif, anodisés en solution aqueuse à 20 V et pendant 20 minutes, et recuits à 450 °C (structure anatase). / This study aimed to design a new photocatalytic support for potential uses in the field of water treatment. Titanium dioxide (TiO2) nanotubes were chosen and studied as a function of their photocatalytic properties towards nitrogenous compounds.TiO2 nanotubes were prepared by electrochemical anodization by varying the applied potential, anodization duration, pH and viscosity of the electrolytic medium (aqueous or glycerol medium), and by the nature of substrates where these nanotubes were deposited (titanium foil (Ti) or deposited on silicon (Ti / Si)). Once anodized, these amorphous and under-stoechiometric (O/Ti <2) were calcined at various temperatures in order to obtain different TiO2 phases (anatase or anatase/rutile). During these different steps, the whole nanotubes obtained were morphologically and structurally characterized par X-ray diffraction (XRD) and scanning electron microscopy (SEM). The photocatalytic activity of the different materials was determined from the photodegradation yields of a model compound, namely 4-nitroaniline. Here again, different factors were studied, such as pH of reaction medium, kind of UV lamps and irradiation durations. The results show that the best photocatalytic performances of TiO2 nanotubes were obtained when deposited on Ti foils, anodized in aqueous medium at 20 V and for 20 minutes, and calcined at 450 °C (anatase phase).

L’objectif de ce travail est d’utiliser les nanoparticules (NPs) de nanosondes fluorescentes de température en particulier dans les films lubrifiants. Le développement de ces nanosondes nécessite la détermination de leurs sensibilités thermiques afin de pouvoir sélectionner les NPs les plus prometteuses. Pour atteindre cet objectif, nous avons présenté deux méthodes d’élaboration utilisées pour la synthèse des nanostructures à base de SiC-3C, la méthode d’anodisation électrochimique et la méthode d’attaque chimique. Dans le premier cas, les analyses FTIR,RAMAN et MET des NPs finales ont montré que la nature chimique de ces NPs est majoritairement formée de carbone graphitique. L’étude détaillée de la photoluminescence de ces NPs a montré que le processus d’émission dépend de la chimie de surface des NPs, du milieu de dispersion et de sa viscosité, de la concentration des suspensions et de la température du milieu. Pour la deuxième famille de NP de SiC, les analyses cohérentes MET, DLS et PL ont montrées une taille moyenne de 1.8 nm de diamètre avec une dispersion de ±0.5nm. Le rendement quantique externe de ces NPs est de l’ordre de 4%. Les NPs dispersées dans l’éthanol, n’ont pas montré une dépendance à la température exploitable pour notre application. Par contre, les NPs de SiC produites par cette voie, étant donné la distribution en taille resserrée et le rendement quantique « honorable » pour un matériau à gap indirect, sont prometteuses pour des applications comme luminophores en particulier pour la biologie grâce à la non toxicité du SiC. Dans le cas des NPs de Si, nous avons également étudié deux types différents de NPs. Il s’agit de : (i) NPs obtenues par anodisation électrochimique et fonctionnalisées par des groupements alkyls (décène, 1-octadécène). Nous avons mis en évidence pour la première fois une très importante variation de l’énergie d’émission dEg/dT avec la température de type red-shift entre 300 et 400K. Les mesures de(T) conduisent à une sensibilité thermique de 0.75%/°C tout à fait intéressante par rapport aux NPs II-VI. De plus il a été montré que la durée de vie mesurée n’est pas fonction de la concentration. (ii) NPs obtenue par voie humide et fonctionnalisées par le n-butyl. Pour ce type de NPs nous avons mis pour la première fois en évidence un comportement de type blue-shift pour dEg/dT de l’ordre de -0.75 meV/K dans le squalane. Pour ces NPs, la sensibilité thermique pour la durée de vie de 0.2%°C est inférieure à celle des NPs de type (i) mais largement supérieure à celle des NPs de CdSe de 4 nm (0.08%/°C). La quantification de cette la sensibilité à la température par la position du pic d’émission dEg/dT et de la durée de vie nous permet d’envisager la conception de nanosondes de température basée sur les NPs de Si avec comme recommandations l’utilisation de NPs obtenues par anodisation électrochimique et de la durée de vie comme indicateur des variations en température. / The goal of this study is the use of Si and SiC nanoparticles (NPs) as fluorescent temperature nanoprobes particularly in lubricating films. The development of these nanoprobes requires the determination of their thermal sensitivity in order to select the best prospects NPs. To achieve this goal, we presented two preparation methods used for the synthesis of 3C-SiC based nanostructures : (i) anodic etching method and (ii) chemical etching method. In the first case, the FTIR, Raman and TEM analysis of final NPs showed that the chemical nature of these NPs is formed predominantly of graphitic carbon. The detailed photoluminescence study of these NPs showed that the emission process depends on the surface chemistry of the NPs, the dispersion medium and its viscosity, the suspension concentration and temperature of the environment.. In the second case, coherent TEM, DLS and PL analyzes showed an average size of 1.8 nm in diameter with a dispersion of ±0.5 nm. The external quantum efficiency of these NPs is 4%. NPs dispersed in ethanol, did not show an exploitable fluorescence dependence on temperature for our application. On the other hand, 3C-SiC NPs produced by this way, given the narrow size distribution and the reasonably high quantum yield for an indirect bandgap material, are promising for applications such as luminophores in particular in the biology field thanks to nontoxicity of SiC. In the case of Si we studied also two different types of NPs. (i) NPs obtained by anodic etching and functionalized by alkyl groups (decene, octadecene). We have demonstrated for the first time an important red-shift in the emission energy dEg/dT with temperature from 300 to 400K. The PL lifetime measurement(T) lead to a thermal sensitivity of 0.75% /°C very interesting compared to II-VI NPs. Furthermore it has been shown that t is not depending on the concentration. (ii) NPs obtained by wet-chemical process and functionalized with n-butyl. For this type of NPs we have identified for the first time a blue-shift behavior of dEg dT in the order of -0.75 meV/K in squalane. The thermal sensitivity for the PL lifetime of these NPs is 0.2%/°C, which is lower than that of NPs obtained by anodic etching method, but much greater than that of CdSe NPs with 4 nm of diameter (0.08%/°C). Quantification of the temperature sensitivity by the position of emission peak dEg/dT and the PL lifetime dτ/dT allows us to consider the realization of temperature nanoprobes based on Si NPs with recommendations to use Si NPs obtained by anodic etching method and PL lifetime as an indicator of temperature changes.

Electrochemical anodization is a facile technique to synthesize ordered oxide nanostructures. Though the number of materials exhibiting anodized nanostructures has increased considerably in the recent years, only nanoporous alumina and nanotubular titania have been investigated extensively for various applications. Anodized nanostructures, nanotubes and nanopores, of zirconia are also of considerable interest for applications such as templates, sensors and solid-oxide fuel cells. In spite of the potential applications of zirconia, these nanostructures have been barely studied. As most of these applications require elevated temperatures in excess of 400C, thermal stability becomes an important attribute. Even though zirconia (Tm=2715C) has as higher melting point than alumina(Tm = 2072C), literature reports and initial research showed that the thermal stability of anodized zirconia was limited to 500C-1 h compared to 1000C-4 h for alumina. The work carried out as a part of this research showed that halide ions used in the synthesis are the possible cause for the lower thermal stability. Chemical treatment of the zirconia membranes to neutralize the halide ions helped enhance the stability to 1000C-1 h, thus, improving their usability for most of the applications mentioned above. Most of the current reported work on aluminum, zirconium, and titanium is predominantly limited to anodization of foils which can only yield free-standing nanostructures. As synthesis of these nanostructures on a substrate would further facilitate their usage, supported anodized zirconia nanostructures were synthesized by anodizing sputtered zirconium films. This study showed that the anodized morphology depends strongly on the sputtered film microstructure, which changes in accordance with the Thornton’s zone diagrams. A general approach thus developed is expected to be applicable to anodization of all metallic films. Most applications involving zirconia also require stabilization against a tetragonal-monoclinic phase transformation by suitable alloying such as with yttria. Towards this end, routes to develop anodized yttria-stabilized zirconia nanostructures, which are nonexistent, were explored. The synthesis of yttria stabilized zirconia nanostructures with no detectable monoclinic phase was achieved. Yttrium alloying using a solution treatment was found to enhance stability of the supported nanostructures to 900C-16 h, which makes it possible to now evaluate these nanostructures, especially for micro-SOFC applications.

Synopsis of the thesis entitled “Titanium Nitride-Based Electrode Materials for Oxidation of Small Molecules: Applications in Electrochemical Energy Systems” submitted by Muhammed Musthafa O. T under the supervision of Prof. S. Sampath at the Department of Inorganic and Physical Chemistry of the Indian Institute of Science for the Ph.D degree in the faculty of science. Fuel cells have been the focus of interest for many decades because of the ever increasing demands in energy. Towards this direction, there have been considerable efforts to find efficient electrocatalysts to oxidize small organic molecules (SOMs) such as methanol, ethanol, glycerol, hydrazine and borohydride that are of potential interest in direct fuel cells. Most studies revolve around platinum which is the best electrocatalyst known for the oxidation of many SOMs. However, platinum is extremely susceptible to carbon monoxide (CO) poisoning which is an intermediate in the electrooxidation of aliphatic alcohols. The best known catalyst, platinum-ruthenium alloy (PtRu), suffers from leaching of Ru during cycling resulting in decrease in efficiency in addition to loss of precious metal. Another important aspect of fuel cell catalyst degradation is corrosion of widely-used carbon support, under fuel cell conditions. Corrosion of carbon support weakens the adherence of catalyst particles on the support and in turn results in loss of catalyst and also in its easy oxidation. Carbon corrosion is also reported to decrease the electronic continuity of the catalyst layer. Hence, replacement of carbon support with durable material is required. The present research explores the use of non-carbonaceous, transition metal nitride for anchoring catalytic particles. The favorable physicochemical properties of titanium nitride (TiN) such as extreme hardness, excellent corrosion resistance in aggressive electrolytes, resistance to nearly all chemicals, salt and humidity, very good support for the adherence of fuel cell catalysts and excellent electronic conductivity motivated us to use this material for anchoring fuel cell catalysts such as Pt, PtRu and Pd. In the present studies, TiN coated on stainless steel (SS 304) surface is used as an electrode material. Catalysts such as Pt, Pd and PtRu are anchored on to TiN and used for the oxidation of methanol and ethanol in acidic as well as in alkaline media. Use of bare TiN is explored for the oxidation of sodium borohydride. The efficiency of TiN supported catalysts are compared with carbon supported ones. Preliminary studies on the use of TiN supported catalysts in fuel cells have been conducted as well. Figure 1 shows the topographic atomic force microscopic (AFM) image in combination with scanning Kelvin probe (SKP) image of platinized TiN (Pt-TiN) surface. Since Pt particles are metallic, they are expected to show lower work function values than that of TiN domains which is indeed observed in figure 1B where the location of Pt particles is shown as dip in the work function. Very interestingly, the interface of Pt-TiN possesses very different work function values confirming the existence of metal-support interaction and this is expected to have positive implications in fuel cell catalysis. Figure 1. Contact mode AFM (A) and the corresponding scanning Kelvin probe image (B) of Pt-TiN surface. Figure 2. Cyclic voltammograms of Pt-TiN and Pt-C electrodes in 0.5 M H2SO4 containing 0.5 M methanol at a scan rate of 10 mV/s. Loading of the catalyst used is 1 mg of Pt/cm2. The performance of Pt-TiN and PtRu-TiN are compared with the corresponding carbon supported catalysts (Pt-C, PtRu-C) for the electrooxidation of methanol. Figure 2 shows the voltammograms obtained on Pt-TiN and Pt-C in presence of acidified methanol. TiN supported catalyst performs better than carbon supported catalyst in terms of high currents at low over voltages (based on I-t measurements), long term stability and high exchange current densities (based on Tafel studies). The electrochemical characteristics of methanol oxidation on Pt-TiN and Pt-C catalysts are given in table 1. The current densities observed on TiN supported catalyst are almost three times higher than that of carbon supported catalyst confirming the promoting effect of TiN support towards methanol oxidation reaction. The performance of Pt-TiN electrocatalyst under fuel cell conditions reveals peak power densities close to 396 mW/cm2 at a current density of 375 mA/cm2, at 90C. Table 1. Characteristics of methanol oxidation on TiN and carbon supported catalysts in acidic medium. Material Onset Ep (mV) Ip EAA Ip Ip/Ib E=Ep-Eb potential (mA/mg (cm2/mg)b (mA/cm2 (mV) of Pt)a of Pt)c (mV) Pt-TiN 170 720 56 78.4 0.714 1.24 82 Pt-C 250 700 18 68.6 0.262 0.98 106 a Mass activity; Ip is the forward peak current and Ib is the reverse peak current; Ep and Eb are forward and reverse peak potentials. b Electrochemically active area (EAA) c Current density normalized for EAA Figure 3. In-situ FTIR spectra on bare TiN surface as a function of applied DC bias vs.SCE. The spectra are shown in regions of 1000 to 2000 cm-1 (A) and 2500 to 4000 cm-1 (B). Electrolyte used is 0.5 M methanol in 0.5 M H2SO4. Reference spectrum is obtained at 0 V. In-situ FTIR spectroelectrochemical measurements have been carried out to understand the intermediates and products formed during methanol oxidation. TiN surface is highly reflective and is quite amenable for reflectance IR studies. Figure 3 shows the potential dependant spectral characteristics of TiN in methanolic sulphuric acid. The bands observed at 1600 and 3600 cm-1 correspond to –OH bending and stretching vibrations of adsorbed water molecules. Interestingly, bands corresponding to adsorbed water are observed even at remarkably low over potentials of around 0.1 V vs. SCE where CO poisoning of Pt can be very severe. This experiment confirms the ability of inexpensive TiN to function like expensive Ru in fuel cell catalysis. Similar studies have been carried out for ethanol electrooxidation on TiN supported catalysts such as Pd, Pt and PtRu in acidic as well as alkaline conditions. Adherence of fuel cell catalyst on to TiN and carbon support is followed by cycling the electrode potential continuously as shown in figure 4. The adherence of Pd on TiN surface is very good and the stability tests reveal that Pd adheres and remains on TiN for a long time as compared to carbon support. Figure 4. Cyclic voltammograms of Pd-C (A) and Pd-TiN (B) in 1 M KOH at 100 mV/s. Pd loading used is 83 µg/cm2. In the chapter on borohydride oxidation, bare TiN electrode is used for the electrochemical oxidation of sodium borohydride. In direct borohydride fuel cells (DBFC), H2 evolution that occurs at low over voltages decreases the apparent number of electrons transferred and consequently the fuel cell efficiency. TiN has been shown to be a relatively H2 evolution-free electrocatalyst for borohydride oxidation (figure 5A). As shown in figure 5A, no H2 oxidation is observed (below -0.5 V) on TiN surface with increase in concentration of borohydride. This point to the fact that direct oxidation of borohydride is very favourable on TiN electrode and is confirmed by fuel cell measurements as shown in figure 5B. Non-platinum DBFCs using TiN as the anode (borohydride oxidation) and prussian blue supported carbon (PB-C) as the cathode (oxygen or hydrogen peroxide) electrocatalysts (figure 5B) reveal peak power density of 107 mW/cm2 for a current density 130 mA/cm2, at 80C. Figure 5. Cyclic voltammograms of TiN in 1 M NaOH containing varying concentrations of borohydride at a scan rate of 20 mV/s (A). Polarization studies of DBFC with TiN anode catalyst and PB-C (prussian blue supported on carbon) cathode catalyst (B). Anolyte is 0.79 M borohydride in 5 M NaOH and catholyte is 2.2 M acidified H2O2. The second aspect of the thesis is related to the use of TiN to prepare visible light active, nitrogen doped TiO2 (N-TiO2). This is carried out by electrochemical anodization of TiN in 0.5 M HNO3 at 1.4 V. The X-ray photoelectron spectroscopy (XPS) suggests the formation of oxide phase on anodized TiN surface (figure 6A) and is confirmed by reflectance UV-Visible spectroscopy. The visible light activity is used for the sunlight induced reduction of graphene oxide to reduced graphene oxide. As shown in the Raman spectra (figure 6B), a negative shift of the D and G band positions by about 20 cm-1 and the intensity ratio reversal after reduction confirms the formation of reduced graphene oxide on N-TiO2. Figure 6. (A) Ti (2p) region of XPS of fresh TiN and anodized TiN. Anodization has been carried out at 1.4 V vs. SCE in 0.5 M HNO3. (B) Raman spectra of exfoliated graphene oxide on anodized TiN before and after sunlight induced reduction. In summary, TiN has been shown to be an active support material for fuel cell catalysts in the present studies. The appendix details the basic electrochemical studies on TiN using various redox couples, electroploymerization of aniline and the formation of nanostructures on TiN surface. (For figures pl refer the abstract pdf file)

Ce travail de thèse traite de la production d’hydrogène par le procédé de photoélectrocatalyse en utilisant une photoanode à base de nanotubes de TiO2 verticalement alignés. L’utilisation du TiO2 étant limité pour des applications solaires en raison de son large gap, il est nécessaire de le modifier. Deux approches sont proposées pour modifier les nanotubes de TiO2 et leur permettre d’absorber la lumière visible. La première est une modification chimique du TiO2 par co-dopage cationique-anionique (Ta-N) ou (Nb-N). Les cations sont insérés durant la croissance des nanotubes grâce à une approche inédite, et l’azote est inséré durant le traitement thermique. Ceci a pour effet la formation d’orbitales hybrides qui entraîne une réduction du gap et une activité sous lumière visible, tout en permettant une stabilité de la structure. La seconde approche consiste à déposer des nanoparticules d’Ag sur la surface des nanotubes de TiO2. Grâce au contrôle de la morphologie des nanoparticules d’Ag, leur résonnance plasmonique permet de stimuler l’absorption du TiO2 et ainsi d’augmenter son rendement à la fois sous lumière UV et sous lumière visible. / This work is about the production of hydrogen by photoelectrocatalysis using a vertically aligned TiO2 nanotubes based photoanode. Utilization of TiO2 for solar applications is limited due to its large band gap, it has to be modified. Two approaches are proposed for the modification of the TiO2 nanotubes to make them absorb visible light. The first one is the chemical modification of the TiO2 by (Ta-N) or (Nb-N) cationic-anionic co-doping. Cations are inserted during the growth of the nanotubes by a novel approach, and nitrogen is inserted during heat treatment. This leads to the formation of hybrid orbitals resulting in a band gap reduction and of activity under visible light. The second approach consists of the deposition of Ag nanoparticles on the surface of the TiO2 nanotubes. Thanks to the control of the morphology of the Ag nanoparticles, their plasmonic resonance can enhance the absorption of TiO2 and thus increase its activity both under UV and visible light.

Au vu des limitations rencontrées par la miniaturisation des circuits microélectroniques, l’augmentation de performances des systèmes repose largement aujourd’hui sur la fabrication d’empilements de couches minces complexes et innovants pour offrir davantage de compacité et de flexibilité. L’intérêt grandissant pour la réalisation de structures innovantes temporaires, i.e. permettant de réaliser des circuits sur les deux faces d’un même film, nous a mené à évaluer les potentialités d’une technologie combinant le transfert de films minces monocristallins, i.e. la technologie Smart Cut™, et un procédé de de porosification partielle du silicium afin de mettre au point une technologie de double report de film monocristallin. En ce sens, des substrats de silicium monocristallin ont été partiellement porosifiés par anodisation électrochimique. La mise en œuvre de traitements de substrats partiellement poreux a nécessité l’emploi de techniques de caractérisation variées pour dresser une fiche d’identité des couches minces poreuses après anodisation et évaluer l’évolution des propriétés de ces couches en fonction des différents traitements appliqués. Les propriétés chimiques, structurales et mécaniques des couches de Si poreux ont ainsi été étudiées via l’utilisation de différentes techniques de caractérisation (XPS-SIMS, AFM-MEB-XRD, nanoindentation, technique d’insertion de lame, etc.). Ces études ont permis d’appréhender et de décrire les mécanismes physiques mis au jeu au cours des différents traitements et de déterminer les caractéristiques {porosité, épaisseur} optimales des couches poreuses compatibles avec les séquences de la technologie proposée. La technologie Smart Cut™ a ainsi été appliquée à des substrats partiellement porosifiés menant à la fabrication réussie d’une structure temporaire de type Silicium-sur-Isolant avec une couche de silicium poreux enterrée. Ces structures temporaires ont été « démontées » dans un second temps par collage polymère ou collage direct et insertion de lame menant au second report de film mince monocristallin par rupture au sein de la couche porosifiée et donc fragile. Les structures fabriquées ont été caractérisées pour vérifier leur intégrité et leurs stabilités chimique et mécanique. Les propriétés cristallines du film mince de Si monocristallin, reporté en deux temps, ont été vérifiées confirmant ainsi la compatibilité des structures fabriquées avec des applications microélectroniques telles que les applications de type « Back-Side Imager » nécessitant une implémentation de composants sur les deux faces du film. Ainsi une technologie prometteuse et performante a pu être élaborée permettant le double report de films minces monocristallins et à fort potentiel pour des applications variées comme les imageurs visibles ou le photovoltaïque. / As scaling of microelectronic devices is confronted from now to fundamental limits, improving microelectronic systems performances is largely based nowadays on complex and innovative stack realization to offer more compaction and flexibility to structures. Growing interest in the fabrication of innovative temporary structures, allowing for example double sided layer processing, lead us to investigate the capability to combine one technology of thin single crystalline layer transfer, i.e. the Smart Cut™ technology, and partial porosification of silicon substrate in order to develop an original double layer transfer technology of thin single crystalline silicon film. To this purpose, single crystalline silicon substrates were first partially porosified by electrochemical anodization. Application of suitable treatments of porous silicon layer has required the use of several characterization methods to identify intrinsic porous silicon properties after anodization and to verify their evolution as function of different applied treatments. Chemical, structural and mechanical properties of porous silicon layers were studied by using different characterization techniques (XPS-SIMS, AFM-MEB-XRD, nanoindentation, razor blade insertion, etc.). Such studies allowed comprehending and describing physical mechanisms occurring during each applied technological steps and well determining appropriated {porosity, thickness} parameters of porous silicon layer with the developed technological process flow. The Smart Cut™ technology was successfully applied to partially porosified silicon substrates leading to the fabrication of temporary SOI-like structures with a weak embedded porous Si layer. Such structures were then “dismantled” thanks to a second polymer or direct bonding and razor blade insertion to produce a mechanical rupture through the fragile embedded porous silicon layer and to get the second thin silicon film transfer. Each fabricated structure was characterized step by step to check its integrity and its chemical and mechanical stabilities. Crystalline properties of the double transferred silicon layer were verified demonstrating the compatibility of such structures with microelectronic applications such as “Back-Side Imagers” needing double-sided layer processing. Eventually, a promising and efficient technology has been developed to allow the double transfer of thin single crystalline silicon layer which presents a high potential for various applications such as visible imagers or photovoltaic systems.