Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 27 for “"ion migration"”.
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Exploiting and Inhibiting Ion Migration to Control Luminescence in Halide Perovskites
This dissertation describes our study on ion migration-driven optoelectronic and structural changes of hybrid metal halide perovskites under light illumination or electric bias, and methods to exploit or inhibit these ion migration processes by implementation of effective passivation approaches. We …
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Development of a new test protocol for the permit Ion migration test
Chloride induced corrosion of steel in concrete is one of the most common reasons for the deterioration of reinforced concrete in both marine and transportation structures. In order to assess the chloride penetration resistance of concrete, the common practice is to remove cores from the structure …
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Ionic Mobility In Stuffed-Silica Minerals
Using a combination of dielectric spectroscopy and atomistic computer simulation techniques, the dynamical behaviour of loosely bound cations in the stuffed-silica minerals nepheline, yoshiokaite and ß-eucryptite has been investigated. The investigation has been extended to include the feldspar …
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Chemical Modifications and Passivation Approaches in Metal Halide Perovskite Solar Cells
This dissertation describes our study on different physical properties of passivated and chemically modified hybrid metal halide perovskite materials and development of highly efficient charge transport layers for perovskite solar cells. We first developed an efficient electron transport layer via …
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Mass transport in the cathode electrode of a molten carbonate fuel cell
… cell (MCFC) is an electro-chemical energy conversion technology that runs on natural gas and employs a molten salt electrolyte. In order to keep the electrolyte in this state, the cell must be kept at a temperature above 500 C, eliminating the need for precious metals as the catalyst. There has …
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Voltage Control of Magnetism in Novel Structured Vertically Aligned Nanocomposite Thin Films
… in novel structured VAN thin films. Both magneto-ionic (MI) and magnetoelectric (ME) systems were studied. Magneto-ionic devices, which utilise voltage-driven ion migration to control magnetic properties, hold promise for energy-efficient, non-volatile magnetic memory and neuromorphic computing. A …
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Developing Ternary Bismuth Chalcogenide Nanocrystals for Photovoltaics and Photodetectors
… still concerns for their widespread implementation. These successes, but also the challenges of LHPs have motivated great efforts across multiple disciplines to search for lead-free and stable alternatives that can have similar optoelectronic properties to LHPs, namely ‘perovskite-inspired …
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Formation and Rupture of Nanofilaments in Metal/TaOx/Metal Resistive Switches
… excellent scaling potential, low power consumption, high switching speed, good retention and endurance properties. Although, various mechanisms have been proposed to explain the switching behavior in CBRAM devices, i.e. metal ion migration and subsequent formation and rupture of conductive …
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Development of a portable microfluidic system for monitoring ions river water
… by environmental changes and industrialisation. The presence of various nutrient contaminants in surface water poses a serious threat to human health. The initial step for the development of this predictive model is to have an in situ monitoring system that provides high frequency screening …
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Synthesis and Study of Stimuli-Responsive Fluorescent Polymeric Thin Films for Early Corrosion Detection by Directly Monitoring Iron Dissolution from Steel Substrates
<p>The successful measurement and prediction of material lifetimes is of high importance for proper maintenance on metal infrastructures for prevention of asset loss through corrosive processes. Current testing protocols include mismatched accelerated weathering techniques in combination with …
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Elucidating Dopant Migration Mechanism for the Controlled Dopant Locations/Distribution within Core/Shell Nanocrystals
… the fundamental principles behind transition metal ion doped semiconducting materials has drawn immense interest when designing ideal systems for use in optical and electronic devices. Dopant ions have been found to diffuse/migrate throughout solid materials when the thermal energy of the …
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Šiuolaikinių keramikos konservavimo metodų kūrimas ir pritaikomumo tyrimas /
… and buildings. In other words, the conservation procedure must preserve an object for the future rather than cause even more damage. As a result, the search for and development of new, advanced materials and technologies for the conservation of cultural goods are among the most significant …
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Development and application of new methods for the conservation of ceramics /
… and buildings. In other words, the conservation procedure must preserve an object for the future rather than cause even more damage. As a result, the search for and development of new, advanced materials and technologies for the conservation of cultural goods are among the most significant …
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Enhancing Stability in Quantum-Dot and Perovskite Optoelectronic Devices through Compositional Engineering and Surface Treatment
Solution-processed quantum dots (QDs) and metal-halide perovskites are of interest inoptoelectronics because of their sharp color, high absorption, and bright emission. However, their further progress is hampered today by limited operating stability. In this thesis, I study how compositional …
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Halide Perovskite and Metal-Organic Framework Composites for X-ray Detection
Our ability to detect X-ray radiation and generate detailed images on internal structures in a non-destructive manner, has had profound impacts on all of our lives. Whether that is through medical imaging, allowing vital diagnosis of tumours and visualisation of broken bones; through security …
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Understanding and optimizing perovskite optoelectronic devices with multi-dimensional imaging techniques
This thesis explores the application of multi-dimensional optical imaging techniques in understanding and optimizing perovskite-based optoelectronics. Chapters 1 and 2 give the motivation behind this work and background to perovskite optoelectronics and machine learning. Chapter 3 introduces the …
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Investigations on Organic Vertical Transistors and Defect Minimization in Hybrid Perovskites
The investigations on organic semiconductors and organometal halide perovskite (OHP) semiconductors have enabled tremendous research achievements for low cost, high performance, flexible optoelectronic applications such as light emitting diodes (LED), photovoltaics (PV) and field effect transistors …
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Effects of radiation damage and composition on phase separation in borosilicate nuclear waste glasses
… phase. In this thesis, the formation and stability of $\textit{CaMoO4}$ in a borosilicate glass against the attack of internal radiation was investigated. It is a fundamental study that simplified the composition to known contributors of molybdate speciation, and further splits the …
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Oxygen permeation and thermo-chemical stability of oxygen separation membrane materials for the oxyfuel process
The reduction of CO2 emissions, generally held to be one of the most significant contributors to global warming, is a major technological issue. CO2 Capture and Storage (CCS) techniques applied to large stationary sources such as coal-fired power plants could efficiently contribute to the global …
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Alkaline Potassium Polyacrylate Electrolytes for Rechargeable Zinc-Manganese Dioxide Batteries
… use of liquid electrolytes, including the formation of electrochemically inactive compounds and shape change of Zn electrodes during charge and discharge cycling. This led to incorporation of an alkaline polymer electrolyte as an alternative to the liquid KOH electrolyte in Zn-MnO<sub>2</sub> …
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