The Photovoltaic (PV) systems and the semiconductor PV technologies are heavily impacted by shading conditions; total or partial. Nearby residential buildings, commercial buildings, objects, etc. are likely to cause shade on the PV installations.  This study focuses on the evaluation of the effect of shading on thin-film PV modules, which were analyzed under two categories: single thin-film module and a string of modules installed at the University of Gävle, Sweden. The measurement was made by using METREL MI 3109 Euro test instrument. The study intends to help researchers to analyze the variation in the output performance parameters and behavior considering different types of shading on the thin-film modules. Experiments have been performed by creating full and partial shading (uniform and nonuniform) by using plastic foil, opaque board, wooden pole, and tape to emulate different types of natural shading conditions.  The findings show a loss in power due to shading. In the single thin-film modules, which do not have any diode between the cells; reverse breakdown, power dissipation and generation of hot spots are caused by the cells which are partially shaded.  In the string of modules installed at the University of Gävle, Sweden; under partial shading conditions the diodes are activated below certain voltage when current is high, leading to current bypass and therefore prevents the module from the damage caused by high heat generation. Under the condition of extremely low shading by a wooden pole, the diodes were not activated; however reverse breakdown was observed similar to the case of partial shading in single thin-film modules.

This research was undertaken to develop state-of-the-art interfacially polymerized (IP) defect-free thin-film composite (TFC) membranes and understand their structure-function-performance relationships. Recent research showed the presence of defects in interfacially polymerized commercial membranes which potentially deter performance in liquid separations and render the membranes inadequate for gas separations. Firstly, a modified method (named KRO1) was developed to fabricate interfacially polymerized defect-free TFCs using m-phenylene diamine (MPD) and trimesoyl chloride (TMC). The systematic study revealed the ability to heal defects in-situ by tweaking the reaction time along with considerably improving the membrane crosslinking by controlling the organic solution temperature. The two discoveries were combined to produce highly crosslinked, defect-free MPD-TMC polyamide membranes which showed exceptional performance for separating H2 from CO2. Permeance and pure-gas selectivity of the membrane increased with temperature. H2 permeance of 350 GPU and H2/CO2 selectivity of ~100 at 140 °C were obtained, the highest reported performance for this application using polymeric materials to date. Secondly, the membranes produced using KRO1 were tested for reverse-osmosis (RO) performance which revealed significantly improved boron rejection compared to commercial membranes reaching a maximum of 99% at 15.5 bar feed pressure at pH 10. The study also unveiled direct correlations between membrane crosslinking and salt separation performance in addition to the membrane surface roughness. Thirdly, this was followed by replacing the conventional IP TMC monomer with a large, rigid and contorted tetra-acyl chloride (TripTaC) monomer to enhance the performance of IP TFCs. The fabricated TFCs showed considerable performance boosts especially for separating of small solutes from organic solvents such as methanol. A rise in H2 permeance was also observed compared to the conventional MPD-TMC TFCs while reaching a maximum H2/CO2 selectivity of 9 at 22 °C. Finally, the research was completed by showing the potential of KRO1 for fabrication of defect-free TFCs using a range of aqueous diamine monomers. KRO1 enabled defect-free gas properties for all monomers used showing exceptional performance for separating H2-CO2 and O2-N2 mixtures. It was further shown that the formulation could also improve the RO separation of interfacially polymerized polyamide TFCs beyond those shown by commercially available TFCs.

A thin film is a material that is many orders of magnitude thinner than it is long or wide. They are commonly found in many forms and have been adapted to a wide variety of uses. The art of origami uses thin films(sheets of paper) and precise folding to create complex, three-dimensional shapes out of flat, quasi two-dimensional sheets, and has emerged as a unique way to solve problems in engineering and science. As technology and devices are scaled to smaller sizes new understanding of origami methods are required to work at these small scales. The interactions between thin films and liquids, substrates that films exist on, and other thin films is the focus of this dissertation. Capillary interactions are used to manipulate and fold thin films that are too thin to be actuated with hands or everyday tools. The relation between the macroscopic and the microscopic interactions at the point where the capillary liquid and the film meet is explored. We show how films can be manipulated by capillary drops and how exactly the force is applied to the film. The adhesive interactions of the film were studied as a method of precisely placing folds for elastic film origami. The capillary peel of a film from a substrate drove folds to desired locations. Adhesion of a film to itself was used to lock these bends in place in lieu of the permanent creases commonly used in plastic systems such as paper. The combination of these two methods enabled the creation of stable, multi-step origami systems from reusable elastic films. This research culminates in the discussion of fundamentally new origami-like designs that rely only on adhesion of the film to itself, which we call kuttsukugami (sticky+paper from Japanese). This new form allows for the creation of shapes that are nearly impossible to create with traditional origami methods such as loops, tubes, and cones. Advances made in capillary and adhesive thin film studies allow for kuttsukugami shapes to be scaled down to microscopic sizes for a huge array of applications including drug delivery, thin electronics, encapsulation, and more.

In the last two decades, there has been considerable development for biosensor devices as the need to more efficient sensing systems is increasing for monitoring the progress of medicine and help with the early diagnosis of the pathogens and treatment of diseases that would reduce the cost of patient care. DNA sensors, in particular, have attracted attention due to their abundance of practical applications in clinical diagnoses and genetic information which increase the demand for DNA probes. On the other hand, the development of the oxide semiconductors thin film transistors (TFT) devices have been greatly increased, owing to their superior electrical properties, lower cost and large coverage areas. Building a bridge across biological elements and electronic interface using advanced (TFT) platforms are based on materials design and device architecture. Here, a solution-processed multi-layer metal oxide (TFT) is explored as a novel DNA sensor. The device engineering combines the novel hetero-structure metal oxide channel that can sustain a 2-dimensional electron gas (2DEG) which leads to a higher mobility and surface functionalization capacity to create an ultrasensitive, highly stable, and versatile DNA sensor. The prototype solid-state TFT sensor features a sub-10 nm-thick metal oxide heterojunction channel of a In2O3 and a top ZnO layer. The devices developed here rely on a pyrene-based molecule as the receptor unit that is known to intercalate into double stranded DNA with a very high-affinity constant and at very low concentration.

Un nanotube de dioxyde de titane autoporteur (TiO2 nts) est exploré en tant qu’électrode négative potentielle pour les microbatteries Li-ion 3D. Différentes modifications chimiques du TiO2 ont été explorées et étudiées, comme le TiO2 allié au Nb, le TiO2 revêtu d'ALD-Al2O3, le titanate de lithium-TiO2 et le TiO2 sulfuré. Le dépôt d'électrolyte polymère à base de PEO (oxyde d'éthylène) (PMMA-PEG) portant le sel de LiTFSI dans du TiO2 a été obtenu par la réaction d'électropolymérisation sur l'anode TiO2 et la cathode Lithum nickel oxyde de manganèse (LNMO). L'objectif principal ici était d'exploiter la surface active des électrodes par électrodéposition et d'améliorer ainsi l'interface électrode-électrolyte. Une telle micro-batterie contenant des électrodes revêtues de polymère révèle que les valeurs de capacité obtenues à différents taux de C sont doublées lorsque les électrodes sont complètement remplies par l'électrolyte polymère par rapport à la micro-batterie à électrodes brutes. Les excellentes performances électrochimiques sont attribuées aux interfaces électrode-électrolyte améliorées dans les deux électrodes / Self-supported titanium dioxide nanotube (TiO2 nts) is explored as a potential negative electrode for 3D Li-ion microbatteries. Different chemical modifications on the TiO2 nts have been explored and studied like Nb-alloyed TiO2 nts, ALD-Al2O3 coated TiO2 nts, Lithium titanate-TiO2 nts and sulphurized TiO2 nts. The deposition of PEO (polyethylene oxide) based polymer electrolyte (PMMA-PEG) carrying LiTFSI salt into TiO2 nts has been achieved by the electropolymerization reaction on the TiO2 nts anode and the Lithum nickel manganese oxide (LNMO) cathode. The main aim here was to exploit the active surface area of the electrodes using electrodeposition and there by enhance the electrode-electrolyte interface. Such a microbattery containing polymer-coated electrodes reveal that the capacity values obtained at different C-rates are doubled when the electrodes are completely filled by the polymer electrolyte compared with the microbattery with the raw electrodes. The excellent electrochemical performance is attributed to the improved electrode-electrolyte interfaces in both the electrodes

Oxygen reduction reaction (ORR) has considerable potential for the pro-duction of electricity, issues with water splitting and many other applications in the energy sector. But in order to increase the efficiency of the reaction an electrocatalyst needs to be introduced. In today’s industrial devices precious and costly metals such as platinum (Pt) are used as catalysts. Other more abundant and cheaper alternatives, for example cobalt oxides, are therefore being investigated. In this thesis, pure cobalt (Co) thin films were synthesised to investigate if thin films can be used for the catalysis of ORR. This was successfully carried out by electrochemically modifying the thin films and grow catalytically ac-tive hexagonal cobalt oxide nanoparticles.   Multicomponent system CoCrFeNi is an emerging alloy system with high research interest for its high corrosion resistance suitable for harsh environments in which the applications for ORR are found. In this thesis, CoCrFexNi were synthesised as thin films. The corrosion resistance of the films was investigated in addition to their catalytic activity. The effect of Fe content on these properties was also studied. The presence of Fe was crucial for the electrochemical activation of films and catalytic activity towards ORR.  In summary, this thesis shows that cobalt based thin films can be used as catalysts combined with corrosion resistance for ORR applications.

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第18382号 / エネ博第294号 / 新制||エネ||61(附属図書館) / 31240 / 京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻 / (主査)教授 佐川 尚, 教授 八尾 健, 教授 萩原 理加 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20334号 / 工博第4271号 / 新制||工||1662(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 安田 秀幸, 教授 酒井 明, 准教授 野瀬 嘉太郎 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20933号 / 理博第4385号 / 新制||理||1630(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 長谷川 健, 教授 倉田 博基, 教授 小野 輝男 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21785号 / 工博第4602号 / 新制||工||1717(附属図書館) / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 村田 靖次郎, 教授 大江 浩一, 教授 中村 正治 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM