Conductive polymers, since from their discovery, have become a prominent area of research and found many useful applications in all fields of our daily life. Examples are light emitting diodes, heat generation, chemical sensors and electro-active membranes. Polymer coated textile substrates give flexible and lightweight materials. One well utilized and thoroughly explored conductive polymer is poly(3,4-ethylenedioxythiophene) also known as PEDOT. Although there are different ways to produce PEDOT one of the most common is the VPP technique. The typical procedure when using VPP is to introduce the monomer vapor to an oxidant coated substrate so that it polymerizes on the surface of the substrate. Throughout this study, the VPP technique has been used to produce PEDOT on different textile fibers. Aim was first of all optimizing the process gaining low electric resistance, i. e. high conductivity, of produced coated fibers but also multilayer coatings of fibers. Outcome indicates some parameters not having a clear influence over the results while others had a more distinct impact. A noteworthy result was obtained by coating a substrate, namely lyocell fiber, multiple times with layers deposited directly on each other. This decreased the resistance from 5.1 (± 1.6) kΩ/10 cm to 1.0 (± 0.1) kΩ/10 cm, for one layer and multiple layers respectively. Adding 15 wt. % of the copolymer PEG-PPG-PEG to the oxidant solution decreased the resistance from 6.8 (± 1.2) kΩ/10 cm to 3.9 (± 0.8) kΩ/10 cm. Final conclusion is that among the ways, to improve conductivity for PEDOT coated fibers, applied in this study are best results obtained by multi-layer coating.

Des revêtements céramiques sont obtenus par un procédé de dépôt chimique en phase vapeur assisté par injection liquide pulsée (DLICVD) de précurseurs organométalliques. Des dépôts de carbure de chrome (CrCx) sont élaborés dans un réacteur tubulaire à paroi chaude à partir d’une solution de bis(benzène) chrome dans du toluène pour des températures de 475 °C et sous pression partielle d’azote (pression totale 50 Torr). Une couche d’accroche pouvant être nécessaire pour revêtir des pièces métalliques, tels des aciers et alliages, par un revêtement céramique non-oxyde de type CrCx, des couches de chrome métallique (Cr) et des carbures mixtes Cr-Si-C ont également été élaborées par ce procédé DLICVD. Ainsi, l’ajout d’un additif à base de chlore ou de soufre (par exemple l’hexachlorobenzène ou le thiophénol) dans la solution BBC/toluène permet la déposition de films de chrome métallique (Cr) à 475 °C. De plus, l’utilisation d’une solution de précurseur contenant simultanément du Si et du Cr tel que le tetrakis(trimethylsilylmethyl)chromium dans du toluène mène au dépôt d’un carbure mixte Cr-Si-C pouvant jouer le rôle d’interphase dans des assemblage céramique-métal. Des films de carbure de silicium (SiC) sont obtenus à partir de deux précurseurs (1,3 disilabutane et polysilyléthylène) injectés purs ou en solution également dans du toluène. Les dépôts sont faits dans une gamme de température comprise entre 700 et 800 °C, sous pression partielle d’azote (pression totale 50 Torr). Les films obtenus sont des films amorphes de SiC contenant une faible quantité d’hydrogène (provenant du mécanisme de décomposition des précurseurs) : a-SiC:H. Les films sont stœchiométriques dans le cas de l’injection de précurseur pur, et quasi stœchiométrique lorsque les précurseurs sont dilués dans du toluène. Les films amorphes tels que déposés deviennent nanocristallins en présentant la structure cubique du SiC après recuit sous vide à 1000 °C. L’influence du solvant (toluène) sur la composition, la morphologie et la vitesse de croissance des dépôts est discutée en fonction des systèmes chimiques étudiés et des conditions expérimentales, en particulier les conditions locales dans le réacteur DLICVD telles que les gradients de température et de concentration. Des films de carbure de hafnium (HfC) sont également élaborés par le même procédé à partir d’une solution de bis(cyclopentadiényl)diméthyl hafnium dans du toluène après avoir testé plusieurs précurseurs. Une température de 750 °C est utilisée et l’utilité d’une pression partielle de dihydrogène dans le gaz vecteur azote est démontrée (pression totale 50 Torr, 423 sccm de N2 et 77 sccm de H2). Tels que déposés, ces films sont riches en carbone (C-rich HfCx) et ont une structure quasi-amorphe. Ils deviennent nanocristallins après recuit sous vide à 1000 °C. Enfin, la mise en œuvre de films multicouches céramiques par DLICVD à paroi chaude est mise en évidence par l’élaboration de revêtements multicouches HfC/SiC à 750 °C, sous pression partielle d’un mélange de gaz vecteur N2/H2. Le contrôle du procédé permet une nano structuration de ces revêtements multicouches jusqu’à une bi-période de 100 nm (empilement de 100 couches d’environ 50 nm chacune). La stabilité thermique de ces architectures et des tests préliminaires de résistance à l’oxydation à haute température des films de SiC et HfC/SiC sont discutés. / Ceramic coatings are made from metalorganic precursors by a chemical vapour deposition process assisted by pulsed liquid injection (DLICVD). Chromium carbide (CrCx) films are grown in a tubular hot wall reactor from a solution of bis(benzene)chromium in toluene under partial pressure of nitrogen at 475 °C (total pressure set at 50 Torr). Bonding layers are useful on metallic components, such as steels and alloys, with non-oxide ceramic films such as CrCx, to that purpose metallic chromium (Cr) and mixed carbides Cr-Si-C have been made by DLICVD. Furthermore, adding a chlorinated or sulfur based additive (e.g. hexachlorobenzene or thiophenol) in the BBC/toluene solution allows depositing metallic chromium (Cr) at 475 °C. Moreover, using a precursor containing Si and Cr as tetrakis(trimethylsilylmethyl)-chromium in toluene leads to the deposition of Cr-Si-C mixed carbide. Silicon carbide films are made from two precursors (1,3-disilabutane and polysilylethylene) that have been injected either pure or diluted in toluene. A temperature range of 700 to 800 °C has been used under a partial pressure of nitrogen (total pressure of 50 Torr). SiC films are amorphous and contain a small quantity of hydrogen (hydrogen comes from precursor pyrolysis mechanism): a-SiC:H. Films are stoichiometric when pure precursors are injected, and quasi stoichiometric when precursors are diluted in toluene. As deposited coatings are amorphous and become nanocristalline (cubic SiC structure) after annealing at 1000 °C under vacuum. The influences of the solvent (toluene) on the composition, morphology and growth rate are discussed as a function of the chemical system and experimental conditions, in particular reactor gradient conditions such as temperature and precursors concentration in gas phase. Hafnium carbide films are also made using a solution of bis(cyclopentadiényl)diméthyl hafnium in toluene by the same process. Temperature is set to 750 °C and hydrogen partial pressure has been shown useful (total pressure of 50 Torr, 423 sccm of N2 and 77 sccm of H2). As-deposited films are C-rich HfCx and quasi amorphous. They become nanocristalline after annealing at 1000 °C under vacuum. Finally, ceramics multilayer HfC/SiC coatings were deposited by DLICVD at 750 °C under a partial pressure of a mixture of N2/H2. The process allows a good control of the multilayer nanostructure. Thermal stability and high temperature oxidation preliminary tests on SiC and HfC/SiC films are discussed.

Doctor of Philosophy / Department of Chemical Engineering / James H. Edgar / The semiconductor boron phosphide (BP) has many outstanding features making it attractive for developing various electronic devices, including neutron detectors. In order to improve the efficiency of these devices, BP must have high crystal quality along with the best possible electrical properties. This research is focused on growing high quality crystalline BP films on a variety of superior substrates like AIN, 4H-SiC, 3C-SiC and ZrB₂ by chemical vapor deposition. In particular, the influence of various parameters such as temperature, reactant flow rates, and substrate type and its crystalline orientation on the properties of BP films were studied in detail. Twin-free BP films were produced by depositing on off-axis 4H-SiC(0001) substrate tilted 4° toward [1-100] and crystal symmetry matched zincblende 3C-SiC. BP crystalline quality improved at higher deposition temperature (1200°C) when deposited on AlN, 4H-SiC, whereas increased strain in 3C-SiC and increased boron segregation in ZrB₂ at higher temperatures limited the best deposition temperature to below 1200°C. In addition, higher flow ratios of PH₃ to B₂H₆ resulted in smoother films and improved quality of BP on all substrates. The FWHM of the Raman peak (6.1 cm⁻¹), XRD BP(111) peak FWHM (0.18°) and peak ratios of BP(111)/(200) = 5157 and BP(111)/(220) = 7226 measured on AlN/sapphire were the best values reported in the literature for BP epitaxial films. The undoped films on AlN/sapphire were n-type with a highest electron mobility of 37.8 cm²/V·s and a lowest carrier concentration of 3.15x1018 cm⁻ᶟ. Raman imaging had lower values of FWHM (4.8 cm⁻¹) and a standard deviation (0.56 cm⁻¹) for BP films on AlN/sapphire compared to 4H-SiC, 3C-SiC substrates. X-ray diffraction and Raman spectroscopy revealed residual tensile strain in BP on 4H-SiC, 3C-SiC, ZrB₂/4H-SiC, bulk AlN substrates while compressive strain was evident on AlN/sapphire and bulk ZrB₂ substrates. Among the substrates studied, AlN/sapphire proved to be the best choice for BP epitaxy, even though it did not eliminate rotational twinning in BP. The substrates investigated in this work were found to be viable for BP epitaxy and show promising potential for further enhancement of BP properties.

<p>Large scale and cost-efficient synthesis of carbon nanostructured materials has garnered tremendous interest over the last decade owing to their plethora of engineering and bio-science applications. One promising method is roll-to-roll radio frequency chemical vapor deposition and this work presents a computational investigation of the capacitively coupled radio frequency plasma in such a system. The system operates at moderate pressures (less than 30 mbar) with an 80 kHz square wave voltage input. The computational model aids the understanding of plasma properties and α-γ transition parameters which strongly influence the nanostructure deposition characteristics in the system. One dimensional argon and hydrogen plasma models are developed to characterize the effects of input voltage, gas pressure, frequency, and waveform on the plasma properties. A hybrid mode which displays the characteristics of both α and γ discharges is found to exist for the low cycle frequency 80 kHz square wave voltage input due to the high frequency harmonics associated with a square waveform. The threshold voltage at which the transition between the different regimes occurs is higher for hydrogen than for argon owing to its diatomic nature. Collision radiative modeling is performed to predict the argon emission intensity in the discharge gap. The results are found to lie within 16% of the optical emission spectroscopy measurements with better agreement at the center of the discharge, where the measurement uncertainty is low and the emission by ions is not significant. A quasi-zero dimensional steady state chemistry model which uses the hydrogen plasma properties as inputs predicts high concentrations of C₂H, C₂H₂, C₂H₃⁺, C₂H₄⁺and C₂H₆⁺during carbon nanostructure deposition.</p> <p> </p> <p>Carbon nanostructures are popularly used as field emitters. Field emission based microplasma actuators generate highly non-neutral surface discharges that can be used to heat, pump, and mix the flow through microchannels and offer an innovative solution to the problems associated with microcombustion. They provide a constant source of heat to counter the large heat loss through the combustor surface, they aid in flow transport at low Reynolds numbers without the use of moving parts, and they provide a constant supply of radicals to promote chain branching reactions. This work presents two actuator concepts for the generation of field emission microplasma, one with offset electrodes and the other with planar electrodes. They operate at input voltages in the 275 to 325 V range at a frequency of 1 GHz which is found to be the most suitable value for flow enhancement. The momentum and energy imparted by the charged particles to the neutrals as modeled by 2D Particle-In-Cell with Monte Carlo Collisions (PIC/MCC) are applied to actuate flow in microchannels using 2D Computational Fluid Dynamics modeling. The planar electrode configuration is found to be more suitable for the purpose of heating, igniting and mixing the flow, as well as improving its residence time through a 10 mm long microcombustor. The combustion of hydrogen and air with the help of 4 such actuators, each with a power consumption of 47.5 mW/cm, generates power with an efficiency of 28.8%. Coating the electrode surface with carbon nanostructures improves the combustion efficiency by a factor of 2.5 and reduces the input voltage by a factor of 6.5. Such microcombustors can be applied to all battery based systems requiring micropower generation with the ultimate goal of “generating power on a chip'”.</p>

Thesis advisor: Dunwei Wang / Solar energy, the most abundant and free renewable energy, holds great promise for humanity's sustainable development. How to efficiently and inexpensively capture, covert solar energy and store it for off peak usages constitutes a grand challenge for the scientific community. Photovoltaic devices are promising candidates but are too costly to be implemented in large scales. On a fundamental level, this is due to the dilemma that the length scales of the optical pathways and electrical pathways often do not match within the photovoltaic device materials. Consider traditional Si solar cell as an example, effective light absorption requires up to hundreds of microns material while the photogenerated charge carries can only diffuse less than a few microns or even shorter before recombination. Such a problem may be solved by using Si nanowires (SiNWs) because vertically aligned nanowires can orthogonalize the light absorption and charge carrier collection pathways, thereby enabling the use of low-cost materials for practically appealing solar energy conversion devices. The objective of this thesis work is to explore low-cost synthesis of vertically aligned SiNW arrays and study their performance in both solar energy conversion and storage devices. We developed a method to synthesize vertically aligned SiNW arrays in a hot-wall chemical vapor deposition system with tunable length, doping level, and diameter for systematical studies. Empowered by the synthetic control, various types of vertical SiNW arrays were characterized by both steady-state (photoelectrochemical measurement) and transient (electrochemical impedance spectroscopy) techniques in a photoelectrochemical cell platform. Additionally, SiNWs were demonstrated to be a promising candidate for photoelectrochemical aromatic ketone reduction and CO₂ fixation. The reactions studied in this thesis are in close resemblance to natural photosynthesis and the resulted product molecules are precursors to nonsteroidal anti-inflammatory drugs, ibuprofen and naproxen. Lastly, vertical transparent conductive oxide nanotubes were prepared from vertical SiNW array templates. Ultrathin hematite (Fe₂O₃) film was coated on the nanotube scaffold by atomic layer deposition to form a heteronanostructure photoelectrode for efficient solar water oxidation. Our results highlight the potential of vertically aligned SiNW arrays in solar cell, solar water splitting and artificial photosynthesis applications. / Thesis (PhD) — Boston College, 2012. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

O dióxido de titânio possui diversas aplicações tecnológicas, desde pigmento em tintas, até revestimentos funcionais. É um material resistente à degradação eletroquímica e fotoquímica. Com o aumento da produção industrial de corantes, há um aumento significativo da produção de rejeitos, sendo necessário o desenvolvimento de novas técnicas de degradação, a fim de reduzir a formação de efluentes. Dentre essas técnicas encontram-se os processos oxidativos avançados (POAs), que se baseiam na formação de radicais hidroxila para a degradação dos compostos liberados nos efluentes. A fotocatálise heterogênea utiliza um material semicondutor ativado por radiação ultra-violeta a fim de produzir os radicais hidroxila. Apesar de existirem estudos relacionados à utilização do TiO2 como fotocatalisador, há poucos dados com relação à sua aplicação na forma de filme suportado. Este trabalho teve por objetivos crescer filmes de TiO2 sobre borossilicato, por meio da técnica de deposição química de organometálicos em fase vapor, nas temperaturas de 400 e 500ºC por até 60 minutos, bem como proceder à caracterização microestrutural, morfológica e fotocatalítica desses filmes. Anatase foi a fase identificada em todos os filmes. Os filmes crescidos a 400°C apresentaram estrutura densificada, enquanto que os filmes crescidos a 500°C apresentaram estrutura colunar bem definida. A fotodegradação foi avaliada por meio da degradação do corante alaranjado de metila nos valores de pH 2,00; 7,00 e 10,00. Os resultados de degradação do corante mostraram que a maior eficiência do processo de degradação ocorre em pH = 2. Nessa condição, os melhores resultados ocorrem com o filme crescido por 30 minutos a 400°C, que apresentou 65,3% de degradação. / Titanium dioxide has many technological applications, as pigment in paints, and functional coatings. It is resistant to electrochemical and photochemical degradation. The increase of the industrial production of dyes results in a significant increase in production of wastes, which requires the development of new degradation techniques to reduce the release of effluents. Among these techniques there is the advanced oxidation process (AOP), which is based on the formation of hydroxyl radicals to the degradation of the compounds in the effluent released. The heterogeneous photocatalysis uses a semiconductor material activated by UV radiation to yield hydroxyl radicals. Although there are studies regarding the use of TiO2 as photocatalyst, there are few data related to its application in the form of supported film. The aim of this study was to grow TiO2 films on borosilicate substrate at 400 and 500°C for up to 60 minutes by using metallorganic chemical vapor deposition technique and proceed to the microstructural, morphology and photocatalytic characterization of the films. Anatase phase was identified in all films. The films grown at 400°C presented a densified structure, while the films grown at 500°C showed well defined columnar structure. The photodegradation was assessed by degradation of methyl orange dye in pH 2.00; 7.00 and 10.00. The results of dye degradation showed that the highest efficiency occurred at pH 2. In this condition, the best results occurred for the film grown for 30 minutes at 400°C and presented a degradation of 65.3%.

Neste trabalho, foi realizado o crescimento de nanotubos de carbono pela técnica de deposição química a vapor (CVD) térmica catalítica, utilizando-se filmes finos de níquel como material catalisador, gás metano (CH4) como fonte de hidrocarboneto e nitrogênio (N2) como gás de arraste. Amostras processadas sobre filmes de Ni de 15 nm de espessura, depositados sobre substrato de óxido de silício (SiO2), com temperatura de processo de 900 ºC e tempo de 15 minutos promoveram uma maior densidade de síntese de nanotubos de carbono, utilizando-se um fluxo na proporção de 2 partes de N2 para 1 parte de CH4. Comprovou-se sua síntese através da visualização de sua morfologia por microscopia eletrônica de varredura (SEM) e microscopia eletrônica de transmissão (TEM), além da extração de seu espectro característico por espectroscopia Raman e espectroscopia de dispersão de raio-X (EDS). Em um segundo estudo, depositaram-se sobre substratos de vidro filmes transparentes e condutores (TCF) à base de nanotubos de carbono de paredes múltiplas (MWCNT) comerciais, pela técnica de dip coating. Para isso, realizou-se a dispersão dos nanotubos sob diversas concentrações em água deionizada (DI) com o auxílio do surfactante dodecil sulfato de sódio (SDS), com posterior funcionalização através do ataque químico por ácido nítrico (HNO3), visando sua aplicação na fabricação de células solares. Foram utilizados os equipamento de quatro pontas e curva corrente x tensão (IV) para caracterização elétrica, transmitância por espectrofotometria para caracterização óptica, SEM para a visualização de sua morfologia e espectroscopia Raman para a análise química de suas estruturas. Valores de resistência de folha de 2x105 W/ e transmitância de 65% foram obtidos nas amostras mais concentradas, com 0,2 mg de nanotubos por ml de água DI. Uma etapa de limpeza em água DI pós deposição foi feita para remoção do excesso de surfactante presente no filme, o que prejudica tanto as características elétricas e ópticas, por ser um dielétrico e não ser transparente. Essa limpeza melhorou o valor de transmitância, porém aumentou a resistência de folha, devido à remoção parcial dos nanotubos presentes no filme, interrompendo em certos pontos a malha que promovia a passagem de corrente elétrica. O ataque químico por HNO3 promoveu a criação de algumas quebras na estrutura do carbono, o que é verificado pelo aumento da banda D, característico da presença de defeitos. / In this work, the growth of CNTs was investigated, using chemical vapor deposition (CVD) thermal catalytic technique, carried out by utilizing thin films of nickel as catalyst material, methane (CH4) as hydrocarbon source and nitrogen (N2) as carrier gas. Samples processed onto 15 nm thick Ni films, deposited on silicon oxide (SiO2) substrates, at a temperature of 900 °C for 15 minutes, promoted a higher density of carbon nanotubes, using a gas mixture at the ratio of 2 parts of N2 and 1 part of CH4. This was verified by analysing the nanotubes morphology by scanning electron microscopy (SEM) and transmission electronic microscopy (TEM) and by the extraction of its characteristic spectrum by Raman spectroscopy and energy dispersive spectroscopy (EDS). In a second study, transparent conductive films (TCF) based on commercial multi-walled carbon nanotubes (MWCNT) were deposited on glass substrates by the dip coating technique. To do so, carbon nanotubes (CNTs) with different concentrations were dispersed in deionized water (DI) with the addition of the surfactant sodium dodecyl sulfate (SDS), and subsequent functionalization through chemical attack by nitric acid (HNO3), aiming their application in solar cell fabrication. The four point probe equipment and current x voltage curve (IV) was used for electrical characterization, transmittance for optical characterization, SEM to visualize their morphology and Raman spectroscopy for chemical analysis of their structures. Sheet resistance values of 2x105 W/ and transmittance of 65% were obtained in the most concentrated samples, with 0.2 mg per ml of nanotubes in deionized water (DI). A cleaning stage in DI water after deposition was taken for removal of surfactant excess in the film, which harms both the electrical and optical characteristics, as it is a dielectric and not transparent. This cleaning improved the transmittance value, but increased the sheet resistance due to partial removal of the nanotubes in the film, interrupting at certain points the mesh of CNTs that promoted the passage of electric current. The chemical attack by HNO3 promoted the functionalization by creating some breaks in the carbon structure, which is checked by the observation of the increasing in D band, which is characteristic of defects.

by Fung Chi Keung = 採用脈衝直流電源對靶濺射技術製備銦錫氧化物薄膜的硏究 / 馮志強. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / by Fung Chi Keung = Cai yong mai chong zhi liu dian yuan dui ba jian she ji shu zhi bei yin xi yang hua wu bo mo de yan jiu / Feng Zhiqiang. / Acknowledgements --- p.i / Abstract --- p.ii / 論文摘要 --- p.iii / Table of contents --- p.iv / List of figures --- p.viii / List of tables --- p.xii / Chapter Chapter 1 --- Introduction --- p.1-1 / Chapter 1.1 --- Genesis --- p.1-1 / Chapter 1.2 --- Aims and Objectives --- p.1-1 / Chapter 1.3 --- Layout of Thesis --- p.1-3 / References --- p.1-4 / Chapter Chapter 2 --- Literature Review --- p.2-1 / Chapter 2.1 --- Introduction to transparent conducting oxides (TCOs) --- p.2-1 / Chapter 2.2 --- Indium tin oxide (ITO) --- p.2-2 / Chapter 2.2.1 --- Use of ITO --- p.2-2 / Chapter 2.2.2 --- Structure and properties of ITO --- p.2-3 / Chapter 2.3 --- Properties of ITO films deposited by different growth techniques --- p.2-8 / Chapter 2.3.1 --- Sputtering --- p.2-9 / Chapter 2.3.2 --- Vacuum evaporation --- p.2-11 / Chapter 2.3.3 --- Spray pyrolysis --- p.2-11 / Chapter 2.3.4 --- Chemical vapor deposition (CVD) --- p.2-12 / Chapter 2.3.5 --- Reactive ion plating --- p.2-12 / Chapter 2.4 --- Contradictions in existing literature --- p.2-13 / References --- p.2-15 / Chapter Chapter 3 --- Thin Film Fabrication and Process --- p.3-1 / Chapter 3.1 --- Facing-target sputtering (FTS) --- p.3-1 / Chapter 3.2 --- Asymmetric bipolar pulsed DC power source --- p.3-3 / Chapter 3.2.1 --- Target poisoning --- p.3-3 / Chapter 3.2.2 --- Preferential sputtering --- p.3-4 / Chapter 3.2.3 --- Discussion --- p.3-4 / Chapter 3.3 --- Substrates --- p.3-6 / Chapter 3.3.1 --- Microscopic glass --- p.3-7 / Chapter 3.3.2 --- Corning 7059 glass --- p.3-8 / Chapter 3.3.3 --- Epitaxial growth --- p.3-8 / Chapter 3.3.3.1 --- Epitaxial lattice matching --- p.3-8 / Chapter 3.3.3.2 --- Yttrium stabilized zirconia (YSZ) --- p.3-9 / Chapter 3.3.3.3 --- Sapphire --- p.3-9 / Chapter 3.3.3.4 --- Silicon wafer --- p.3-11 / Chapter 3.3.4 --- Substrate cleaning --- p.3-11 / Chapter 3.4 --- Targets for the reactive sputtering of ITO films --- p.3-13 / Chapter 3.4.1 --- Indium Tin Oxide target (90wt% ln203 : 10wt% Sn04) --- p.3-14 / Chapter 3.4.2 --- Indium Tin alloy target (90wt% In : 10wt% Sn) --- p.3-14 / Chapter 3.5 --- Deposition conditions --- p.3-16 / Chapter 3.5.1 --- Sputter atmosphere --- p.3-16 / Chapter 3.5.2 --- Deposition pressure --- p.3-16 / Chapter 3.5.3 --- Deposition power --- p.3-17 / Chapter 3.5.4 --- Target to substrate distance --- p.3-17 / Chapter 3.5.5 --- Pulse frequency and pulse width --- p.3-17 / Chapter 3.6 --- Deposition --- p.3-17 / References --- p.3-19 / Chapter Chapter 4 --- Measurement and Analysis Techniques --- p.4-1 / Chapter 4.1 --- Resistivity measurement --- p.4-1 / Chapter 4.2 --- "Transmittance, reflectivity and absorption measurements" --- p.4-3 / Chapter 4.3 --- Thickness measurement --- p.4-4 / Chapter 4.4 --- "Crystal structure, surface morphology and roughness measurements" --- p.4-4 / Chapter 4.5 --- Photolithography --- p.4-7 / Chapter 4.6 --- Hall effect measurements --- p.4-8 / References --- p.4-10 / Chapter Chapter 5 --- Experimental results and discussions --- p.5-1 / Chapter 5.1 --- Effect of O2 partial pressure --- p.5-1 / Chapter 5.1.1 --- Deposition rate --- p.5-2 / Chapter 5.1.2 --- Electrical and optical properties --- p.5-4 / Chapter 5.1.3 --- Structure and orientation --- p.5-16 / Chapter 5.1.4 --- Surface morphology and roughness --- p.5-22 / Chapter 5.1.5 --- Conclusion --- p.5-29 / Chapter 5.2 --- Effect of substrate temperature --- p.5-29 / Chapter 5.2.1 --- Electrical and optical properties --- p.5-29 / Chapter 5.2.2 --- Structure and orientation --- p.5-44 / Chapter 5.2.3 --- Surface morphology and roughness --- p.5-49 / Chapter 5.2.4 --- Conclusion --- p.5-54 / Chapter 5.3 --- Effect of vacuum annealing --- p.5-54 / Chapter 5.3.1 --- Electrical and optical properties --- p.5-54 / Chapter 5.3.2 --- Conclusion --- p.5-59 / Chapter 5.4 --- Effect of different substrates --- p.5-59 / Chapter 5.4.1 --- Comparison of heteroepitaxial and polycrystalline ITO films --- p.5-60 / Chapter 5.4.2 --- Conclusion --- p.5-63 / Chapter 5.5 --- Effect of film thickness --- p.5-64 / Chapter 5.5.1 --- Film thickness calibration --- p.5-64 / Chapter 5.5.2 --- Electrical properties --- p.5-64 / Chapter 5.5.3 --- Conclusion --- p.5-67 / Chapter 5.6 --- Effect of deposition pressure --- p.5-68 / Chapter 5.6.1 --- Deposition rate --- p.5-68 / Chapter 5.6.2 --- Electrical properties --- p.5-70 / Chapter 5.6.3 --- Conclusion --- p.5-70 / Chapter 5.7 --- Effect of target pre-conditioning --- p.5-72 / Chapter 5.8 --- Conclusion --- p.5-72 / References --- p.5-74 / Chapter Chapter 6 --- Further works --- p.6-1 / Appendix I

Lau Wing Fai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 101-105). / Abstracts in English and Chinese. / Abstract --- p.i / Abstract (Chinese version) --- p.iii / Acknowledgement --- p.iv / Content --- p.v / List of figure caption --- p.vii / List of table caption --- p.xi / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Nomenclature --- p.1 / Chapter 1.2 --- Comparison of diamond and DLC --- p.2 / Chapter 1.3 --- Comparison of the amorphous hydrogenated and hydrogen free amorphous carbon --- p.4 / Chapter 1.4 --- Application of DLC --- p.7 / Chapter 1.5 --- ta-C growth mechanism --- p.9 / Chapter 1.6 --- Recent activities on ta-C films --- p.11 / Chapter 1.7 --- Goal of this project and organization of this thesis --- p.11 / Chapter Chapter 2 --- Deposition of ta-C films / Chapter 2.1 --- Ta-C film deposition systems --- p.12 / Chapter 2.1.1 --- Direct ion beam deposition --- p.13 / Chapter 2.1.2 --- Laser ablation --- p.14 / Chapter 2.1.3 --- Mass selected ion beam deposition (MSIBD) --- p.15 / Chapter 2.1.4 --- Arc discharge and filtered arc discharge (FAD) methods --- p.16 / Chapter 2.2 --- The pulsed filtered vacuum arc deposition system --- p.18 / Chapter 2.2.1 --- Working principle --- p.18 / Chapter 2.2.2 --- Film thickness control --- p.20 / Chapter 2.3 --- System modification --- p.22 / Chapter 2.3.1 --- Cathode erosion improvement --- p.22 / Chapter 2.3.2 --- Enhancement of stabilization of the cathodic arc --- p.23 / Chapter 2.4 --- Sample preparation --- p.24 / Chapter 2.4.1 --- Film deposition --- p.24 / Chapter 2.4.2 --- Thermal treatments --- p.24 / Chapter Chapter 3 --- Characterization methods / Chapter 3.1 --- Raman spectroscopy --- p.25 / Chapter 3.2 --- IR Photoelasticity (PE) --- p.27 / Chapter 3.2.1 --- Basic principle --- p.27 / Chapter 3.2.2 --- Senarmont method --- p.30 / Chapter 3.3 --- Ellipsometry --- p.33 / Chapter 3.3.1 --- Principle of ellipsometry --- p.33 / Chapter 3.3.2 --- Mathematical representation --- p.37 / Chapter 3.3.2a --- Bulk layer --- p.37 / Chapter 3.3.2b --- Single layer structure --- p.38 / Chapter 3.3.3 --- Spetroscopioc rotating analyzer ellipsometer --- p.39 / Chapter 3.3.4 --- Analysis method --- p.42 / Chapter 3.3.5 --- Forouhi and Bloomer (F.B.) model --- p.43 / Chapter 3.4 --- Tribology --- p.44 / Chapter 3.4.1 --- The definition of friction --- p.44 / Chapter 3.4.2 --- Tribometer --- p.46 / Chapter Chapter 4 --- Results / Chapter 4.1 --- As-deposited samples --- p.47 / Chapter 4.1.1 --- Sp3 fraction --- p.47 / Chapter 4.1.2 --- Stress --- p.52 / Chapter 4.1.3 --- Optical properties --- p.57 / Chapter 4.1.3.1 --- Optical model for ta-C film --- p.57 / Chapter 4.1.3.2 --- Figure of merit --- p.59 / Chapter 4.1.3.3 --- Result and discussion --- p.59 / Chapter 4.1.4 --- Mechanical properties --- p.70 / Chapter 4.1.4.1 --- Hardness --- p.70 / Chapter 4.1.4.2 --- Friction --- p.76 / Chapter 4.2 --- Annealed samples --- p.81 / Chapter 4.2.1 --- Thermal stability of the ta-C film --- p.81 / Chapter 4.2.2 --- Stress relaxation --- p.85 / Chapter 4.2.3 --- Stress and G peak shift --- p.92 / Chapter Chapter 5 --- Future work / Chapter 5.1 --- Film roughness and thickness profile improvement --- p.95 / Chapter 5.2 --- Pulsed substrate bias --- p.97 / Chapter 5.3 --- Field emission and doping possibility --- p.97 / Chapter Chapter 6 --- Conclusion --- p.98 / Reference --- p.101 / Conference / publications --- p.105

Au Yeung Yue Fung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / Au Yeung Yue Fung. / Abstract --- p.i / 論文摘要 --- p.ii / Acknowledgements --- p.iii / Table of Contents --- p.iv / List of Figures --- p.vi / List of Tables --- p.viii / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Genesis --- p.1-1 / Chapter 1.2 --- Aims and Objectives --- p.1-2 / Chapter 1.3 --- Layout of thesis --- p.1-3 / References --- p.1-4 / Chapter Chapter 2 --- Literature review / Chapter 2.1 --- Introduction to superconductor --- p.2-1 / Chapter 2.2 --- MgB2 --- p.2-3 / Chapter 2.2.1 --- Significance of MgB2 --- p.2-3 / Chapter 2.2.2 --- Structure and properties of MgB2 --- p.2-4 / Chapter 2.2.3 --- Superconducting mechanism of MgB2 --- p.2-5 / Chapter 2.2.4 --- Physical properties of boron and boride --- p.2-7 / Chapter 2.2.5 --- Physical properties of magnesium --- p.2-7 / Chapter 2.2.6 --- Formation of MgB2 --- p.2-8 / Chapter 2.2.7 --- MgB2 thin films --- p.2-9 / Chapter 2.2.7.1 --- Substrate --- p.2-11 / Chapter 2.2.7.2 --- Substrate temperature --- p.2-12 / Chapter 2.3 --- Contradictions as revealed by existing literatures --- p.2-13 / References --- p.2-14 / Chapter Chapter 3 --- Preparation and characterization of bulk MgB2 / Chapter 3.1 --- Bulk MgB2 fabrication / Chapter 3.2 --- Measurement and analysis techniques of bulk MgB2 --- p.3-4 / Chapter 3.2.1 --- XRD --- p.3-4 / Chapter 3.2.2 --- Meissner effect measurement --- p.3-5 / Chapter 3.3 --- Sintering time of MgB2 --- p.3-6 / Chapter 3.4 --- Concentration of Mg in sintering MgB2 --- p.3-8 / Chapter 3.5 --- Sintering temperature of MgB2 --- p.3-11 / Chapter 3.6 --- Thermal stability of MgB2 --- p.3-13 / Chapter 3.7 --- MgB2 in water --- p.3-17 / References --- p.3-19 / Chapter Chapter 4 --- Preparation and characterization of MgB2thin films / Chapter 4.1 --- Thin film deposition --- p.4-1 / Chapter 4.1.1 --- Facing-target sputtering (FTS) --- p.4-2 / Chapter 4.1.2 --- Vacuum system --- p.4-4 / Chapter 4.1.3 --- Asymmetric bipolar pulsed DC power source --- p.4-6 / Chapter 4.2 --- Fabrication of MgB2 targets --- p.4-10 / Chapter 4.3 --- Substrates --- p.4-11 / Chapter 4.4 --- Deposition procedure --- p.4-12 / Chapter 4.5 --- Deposition condition --- p.4-13 / Chapter 4.5.1 --- Deposition power --- p.4-15 / Chapter 4.5.2 --- Deposition pressure --- p.4-13 / Chapter 4.5.3 --- Annealing temperature --- p.4-18 / Chapter 4.5.4 --- Substrate temperature --- p.4-21 / Chapter 4.5.5 --- Conclusion --- p.4-26 / References --- p.4-29 / Chapter Chapter 5 --- Failed attempts of MgB2 films fabrication by in situ method / Chapter 5.1 --- In-situ method --- p.5-1 / Chapter 5.2 --- Additional FTS guns with Mg target --- p.5-2 / Chapter 5.3 --- Diode sputtering --- p.5-4 / Chapter 5.4 --- Co-evaporating fabrication --- p.5-6 / Chapter Chapter 6 --- Conclusion --- p.6-1