Carbon nanotubes (CNTs) are a highly promising material for future interconnects. It is expected that the decoration of CNTs with Cu particles or also the filling of the interspaces between the CNTs with Cu instead of the currently used SiO2 can enhance the performance of CNT-based interconnects. Due to the high aspect ratio of CNTs an appropriate deposition technique has to be applied which is able to coat such structures uniformly. The current work is therefore considered with thermal atomic layer deposition (ALD) of CuxO from the liquid Cu (I) β-diketonate precursor [(nBu3P)2Cu(acac)] and wet oxygen at 135°C on variously pretreated multi-walled CNTs. The different in-situ pre-treatments of the CNTs with oxygen, water vapor and wet oxygen in a temperature range from 100 to 300°C at a pressure of 1.33 mbar have been carried out prior to the ALD to enable uniform nucleation on the otherwise chemical inert CNT surface. The reduction of the CuxO as well as the filling of the space between the CNTs is not part of this work. Variations of the oxidation temperature as well as the oxidation agents resulted in different growth modes of the CuxO. An oxidation with wet oxygen at 300°C yielded in a partially layer like growth of the CuxO. It is expected that this growth mode is connected to a partial destruction of the outer CNT shell due to the oxidation. However, the damage introduced to the CNTs was not high enough to be detected by Raman spectroscopy. For all other investigated pretreatments, the formation of nanoparticles (NPs) was observed by electron microscopy. This formation of CuxO NPs can be explained by the metal-tube-interaction. Furthermore, the NPs probably decorate defect sites of the CNTs due to their higher reactivity. Additionally, analysis of energy-dispersive X-ray spectroscopy and spectroscopic ellipsometry measurements suggests that the used precursor [(nBu3P)2Cu(acac)] requires reactive oxygen surface groups for initiating the ALD growth. The observation of layer-like growth of CuxO on CNTs pretreated with wet oxygen at 300°C appears promising for deposition processes of Cu seed layers on CNTs. However, more aggressive pretreatments at higher temperatures or with more aggressive oxidation agents could be required to enable layer like growth on the entire CNTs.

Les propriétés électriques et physiques de structures à faible dimensionalité ont été étudiées pour des applications dans des domaines divers comme l’électronique, les capteurs. La mesure du bruit bruit à basse fréquence est un outil très utile pour obtenir des informations relatives à la dynamique des porteurs, au piègeage des charges ou aux mécanismes de collision. Dans cette thèse, le transport électronique et le bruit basse fréquence mesurés dans des structures à faible dimensionnalité comme les dispositifs multi-grilles (FinFET, JLT…), les nanofils 3D en Si/SiGe, les nanotubes de carbone ou à base de graphène sont présentés. Pour les approches « top-down » et « bottom-up », l’impact du bruit est analysé en fonction de la dimensionalité, du type de conduction (volume vs surface), de la contrainte mécanique et de la présence de jonction metal-semiconducteur. / Electrical and physical properties of low-dimensional structures have been studied for the various applications such as electronics, sensors, and etc. Low-frequency noise measurement is also a useful technique to give more information for the carrier dynamics correlated to the oxide traps, channel defects, and scattering. In this thesis, the electrical transport and low-frequency noise of low-dimensional structure devices such as multi-gate structures (e.g. FinFETs and Junctionless FETs), 3-D stacked Si/SiGe nanowire FETs, carbon nanotubes, and graphene are presented. From the view point of top-down and bottom-up approaches, the impacts of LF noise are investigated according to the dimensionality, conduction mechanism (surface or volume conduction), strain technique, and metal-semiconductor junctions.

Considerando a relação História-Cinema, a presente dissertação é uma reflexão sobre a produção cinematográfica anarquista da CNT durante a Guerra Civil Espanhola (1936-1939), a partir da análise de três de seus principais filmes de ficção: Carne de Fieras (1936/1992), Barrios Bajos (1937) e Aurora de Esperanza (1937). Eles foram construídos numa estrutura de narrativa clássica e melodramática e, dotados de temáticas diversas, como o adultério, a prostituição assediada por gangsteres e o drama do desemprego, representam uma iniciativa ímpar na construção de um cinema social, sob o comando de uma poderosa organização anarquista e durante o processo revolucionário. Neste sentido, consideramos também os meandros do desenvolvimento do anarquismo e do cinema espanhóis, cujas singularidades imprimiram uma dinâmica específica àqueles filmes. / Considering the relation between History and Cinema, this present dissertation will ponder on the anarchist cinematographic production of CNT during the Spanish Civil War (1936-1939) through the analysis of three of its most important fiction works: Carne de Fieras (1936/1992), Barrios Bajos (1937) and Aurora de Esperanza (1937). They were structured in a classic and melodramatic narrative and, dealing with several themes, as adultery, gangster-linked prostitution and the misfortune of unemployment, they represent a unique initiative in the construction of a social cinema, under the command of a powerful anarchist organization during the revolutionary process. In this sense, well consider the specifics in the development of Spanish anarchism and cinema, for their singular features have given a specific dynamic to those movies.

Since many years, carbon nanotubes (CNTs) have been considered for a wide range of applications due to their outstanding mechanical properties. CNTs are tubular structures, showing a graphene like hexagonal lattice. Our interest in the calculation of the mechanical properties is motivated by several applications which demand the knowledge of the material behavior. One application in which the knowledge of the material behavior is vital is the CNT based fiber. Due to the excellent stiffness and strength of the individual CNTs, these fibers are expected to be a promising successor for state of the art carbon fibers. However, the mechanical properties of the fibers fall back behind the properties of individual CNTs. It is assumed that this gap in the properties is a result of the van-der-Waals interactions of the individual CNTs within the fiber. In order to understand the mechanical behavior of the fibers we apply a molecular mechanics approach. The mechanical properties of the individual CNTs are investigated by using a modified structural molecular mechanics approach. This is done by calculating the properties of a truss-beam element framework representing the CNT with the help of a chemical force field. Furthermore, we also investigate the interactions of CNTs arranged in basic CNT assemblies, mimicking the ones in a simple CNT fiber. We consider the van-der-Waals interactions in the structure and calculate the potential surface of the CNT assemblies.

Este trabalho traz a aplicação de alta pressão e alta pressão/temperatura (4.0 GPa e 400º C), em amostras de nanotubos de carbono de paredes múltiplas (NTCPM) comerciais para a obtenção de amostras compactas. Os NTCPM foram funcionalizados com ácido nítrico e ácido nítrico/ácido sulfúrico e, também foram usados nanotubos de carbono dopados com nitrogênio. Foram também processadas amostras contendo nanotubos de carbono de paredes múltiplas incorporados em matriz de zircônia obtida pelo método sol-gel. Para aplicação da alta pressão foi usado um sistema com câmaras do tipo toroidal, utilizando grafite como meio transmissor de pressão. Foram obtidas amostras macroscópicas autossuportadas e com resistência ao manuseio principalmente nas amostras de nanotubos de carbono funcionalizados com ácido nítrico/ácido sulfúrico incorporados em zircônia. Para a caracterização das amostras foram utilizadas as técnicas de Microscopia Eletrônica de Transmissão, Espectroscopia Raman, Difração de Raios X e isotermas de adsorção/dessorção de nitrogênio com as quais foi possível determinar que mesmo após a aplicação de alta pressão/temperatura os nanotubos de carbono não sofrem significativas modificações na sua estrutura e nas suas propriedades morfológicas e texturais, confirmando então que os NTCPM mantém suas características originais, apresentando condições para aplicações em dispositivos. As amostras macroscópicas contendo nanotubos de carbono de paredes múltiplas incorporados em zircônia apresentaram ainda resistência à carga de milhares de vezes o seu peso e comportamento de materiais semi-condutores. / This work presents the application of high pressure and/or high pressure/temperature (4.0 GPa and 400 ° C), on different samples of commercial multi-walled carbon nanotube (MWCNT) to obtain compacted samples. MWCNT were functionalized with nitric acid and nitric acid/sulfuric acid, and also carbon nanotubes doped with nitrogen. MWCNT incorporated in a zirconia matrix obtained by sol-gel method were also processed. For high pressure application it was used a system with the toroidal-type chamber, using graphite as a pressure transmitting medium. Self-supported macroscopic samples were obtained, easy to handle, especially in samples of functionalized carbon nanotubes with nitric and sulfuric acid and also incorporated in zirconia. To characterize the samples it was used Transmission Electron Microscopy, Raman Spectroscopy, X-ray diffraction and nitrogen adsoption/desorption isotherms and it was determined that even after application of high pressure/temperature carbon nanotubes do not suffer significant changes in their structure and in their morphological and textural properties, confirming that the CNT keeps its original characteristics and providing conditions for device applications. The macroscopic samples containing MWCNT incorporated in zirconia also exhibited resistance to load of thousands times its own weight and behavior like semiconductor materials.

Recently there have been considerable interests in nanometerial study. In this work, we have used carbon nanotubes (CNTs) and polypyrrole (PPy) conducting polymers (CPs) as models to make a nanotube and conducting polymer composite material. Under electro-oxidation condition, the PPy/CNT films can be grown on conventional substrates such as a glassy carbon electrode in aqueous and non-aqueous media. These nano-conjugated materials are based on the doping of CNTs particles into conducting polymer network while oxidatively polymerizing. CNTs serve as dopants and solely supporting electrolytes in the preparation. The CP/CNT new composite materials have showed promise not only in a potential environmental remedy such as conversion of highly toxic Cr(VI) into less harmful Cr(III), but also in electrocatalysis of the quinone/hydroquinone redox reaction. Voltammetry, bulk electrolysis with coulometry, AC impedance, and EQCM techniques have been used to elucidate the preparation, ion transport, and intermolecular interaction processes within these composites.

The objective of this study is to develop a robust portable nano-calorimeter sensor for detection of energetic materials, primarily explosives, combustible materials and propellants. A micro-cantilever sensor array is actuated thermally using bi-morph structure consisting of gold (Au: 400 nm) and silicon nitride (Si3N4: 600 nm) thin film layers of sub-micron thickness. An array of micro-heaters is integrated with the microcantilevers at their base. On electrically activating the micro-heaters at different actuation currents the microcantilevers undergo thermo-mechanical deformation, due to differential coefficient of thermal expansion. This deformation is tracked by monitoring the reflected ray from a laser illuminating the individual microcantilevers (i.e., using the optical lever principle). In the presence of explosive vapors, the change in bending response of microcantilever is affected by the induced thermal stresses arising from temperature changes due to adsorption and combustion reactions (catalyzed by the gold surface). A parametric study was performed for investigating the optimum values by varying the thickness and length in parallel with the heater power since the sensor sensitivity is enhanced by the optimum geometry as well as operating conditions for the sensor (e.g., temperature distribution within the microcantilever, power supply, concentration of the analyte, etc.). Also, for the geometry present in this study the nano-coatings of high thermal conductivity materials (e.g., Carbon Nanotubes: CNTs) over the microcantilever surface enables maximizing the thermally induced stress, which results in the enhancement of sensor sensitivity. For this purpose, CNTs are synthesized by post-growth method over the metal (e.g., Palladium Chloride: PdCl2) catalyst arrays pre-deposited by Dip-Pen Nanolithography (DPN) technique. The threshold current for differential actuation of the microcantilevers is correlated with the catalytic activity of a particular explosive (combustible vapor) over the metal (Au) catalysts and the corresponding vapor pressure. Numerical modeling is also explored to study the variation of temperature, species concentration and deflection of individual microcantilevers as a function of actuation current. Joule-heating in the resistive heating elements was coupled with the gaseous combustion at the heated surface to obtain the temperature profile and therefore the deflection of a microcantilever by calculating the thermally induced stress and strain relationship. The sensitivity of the threshold current of the sensor that is used for the specific detection and identification of individual explosives samples - is predicted to depend on the chemical kinetics and the vapor pressure. The simulation results showed similar trends with the experimental results for monitoring the bending response of the microcantilever sensors to explosive vapors (e.g., Acetone and 2-Propanol) as a function of the actuation current.

The development of wide band gap semiconductors for power and RF electronics as well as high power silicon microelectronics has pushed the need for advanced thermal management techniques to ensure device reliability. While many techniques to remove large heat fluxes from devices have been developed, fewer advancements have been made in the development of new materials which can be integrated into the packaging architecture. This is especially true in the development of thermal interface materials. Conventional solders are currently being used for interface materials in the most demanding applications, but have issues of high cost, long term reliability and inducing negative thermomechanical effects in active die. Carbon nanotubes have been suggested as a possible thermal interface material which can challenge solders because of their good thermal properties and 1-D structure which can enhance mechanical compliance between surfaces. In this work, we have developed a novel growth and transfer printing method to manufacture vertically aligned CNTs for thermal interface applications. This method follows the nanomaterial transfer printing methods pioneered at Georgia Tech over the past several years. This process is attractive as it separates the high growth synthesis temperatures from the lower temperatures needed during device integration. For this thesis, CNTs were grown on oxidized Si substrates which allowed us to produce high quality vertically aligned CNTs with specific lengths. Through the development of a water vapor assisted etch process, which takes place immediately after CNT synthesis, control over the adhesion of the nanotubes to the growth surface was achieved. By controlling the adhesion we demonstrated the capability to transfer arrays of vertically aligned CNTs to polyimide tape. The CNTs were then printed onto substrates like Si and Cu using a unique gold bonding process. The thermal resistances of the CNTs and the bonded interfaces were measured using the photoacoustic method, and the strength of the CNT interface was measured through tensile tests. Finally, the heat dissipation capabilities of the vertically aligned CNTs were demonstrated through incorporation with high brightness LEDs. A comparison of LED junction temperatures for devices using a CNT and lead free solder thermal interface was made.

CNT membrane platforms are biomimetic polymeric membranes imbedded with carbon nanotubes which show fast fluid flow, electric conductivity, and the ability to be grafted with chemistry. A novel micro-dialysis probe nicotine concentration sampling technique was proposed and proved in vitro, which could greatly improve the efficiency and accuracy of future animal transdermal studies. To enhance the scope of transdermal drug delivery which was limited to passive diffusion of small, potent lipophilic drugs, a wire mesh lateral electroporation design was also proposed which could periodically disrupt the skin barrier and enhance drug flux. It was shown that AMP binding aptamer at the tip of carbon nanotubes may act as gatekeepers and regulate ionic transport through CNT membrane. Multiple cycle gating of ionic transport upon AMP binding/unbinding which changes the aptamer conformation was displayed. This CNT membrane-aptamer system closely mimics how protein ion channels modulate ion flow by responding to stimuli, which may have significant impact on active membrane transport. Finally an enhanced electroosmosis concept by “ratchet” functionalization at both ends of carbon nanotubes in was discussed. Direct observation of water transport by electroosmosis was made possible through enhanced flow in vertically aligned high flux CNT membranes.

Die vorliegende Arbeit beschreibt die Synthese und Charakterisierung ethylenglykolfunktionalisierter Carboxylate der Münzmetalle sowie deren Verwendung als Präkursoren in der Herstellung von Nanopartikeln und leitfähigen Metallschichten. Ein Schwerpunkt der Arbeit liegt auf der Verwendung von Kupfer(II)-carboxylaten zur Herstellung von druckbaren Kupfertinten. Es wird gezeigt, wie zentrale Präkursoreigenschaften durch Variation der Carboxylatreste optimiert werden können. Einen zweiten Schwerpunkt bildet die Herstellung von Kupfernanopartikeln durch thermische Zersetzung ethylenglykolfunktionalisierter Kupfercarboxylate. Der Einsatz von Bis- und Tris(triphenylphosphan)kupfer(I)-carboxylaten ermöglicht hierbei die Herstellung von oxidfreien sphärischen Kupfernanopartikeln sowie von Kupferstäbchen unter einfachen experimentellen Bedingungen. Weitere Arbeiten widmen sich der Verwendung von ethylenglykolfunktionalisierten Silber(I)-carboxylaten zur Synthese von Silbernanopartikeln. Der entwickelte Prozess erlaubt die Herstellung blättchenförmiger Silbernanopartikel bei vergleichsweise niedrigen Temperaturen. Auch die Herstellung von blättchenförmigen Kupfersulfidpartikeln durch Thermolyse eines ethylenglykolfunktionalisierten Bis(triphenylphosphan)kupfer(I)-thiocarboxylates wird beschrieben. Schließlich wird gezeigt, wie thermolytisch hergestellte Goldnanopartikel an ethylenglykolfunktionalisierten Kohlenstoffnanoröhren abgeschieden werden können. Der Prozess wurde auf einem Wafer durchgeführt. Die erhaltenen Strukturen ermöglichen eine Verwendung als optischer Sensor.