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 21 for “"Material growth"”.
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Layer-by-Layer Single-crystal Two-dimensional Material Growth by Geometric Confinement
… 1) precise layer control during their growth, 2) maintaining single crystallinity at wafer-scale, and 3) inevitable transfer-process to fabricate heterostructure for various next-generation applications such as spintronics, valleytronics, and optoelectronics. This thesis introduces a …
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Methodology, morphology, and optimization of carbon nanotube growth for improved energy storage in a double layer capacitor
The goal of this thesis is to optimize the growth of carbon nanotubes (CNTs) on a conducting substrate for use as an electrode to improve energy density in a double-layer capacitor. The focus has been on several areas, such as substrate material, growth conditions, catalyst variations, and …
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Community-Based Organizations and the Challenges of the Anthropocene
… dominance of social arrangements prioritizing material growth (related to social power) over other concerns, such as human and non-human well-being, or the ecosystems’ capacity to sustain life. Despite significant potentials to reduce environmental destruction while increasing individual …
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Gallium Nitride-Based HEMT Devices Modeling and Performance Characterization
… at such frequencies. As a result of improved material growth and processing technologies, microwave power densities have been demonstrated in AlGaN/GaN HEMTs that are five to ten times greater than that of corresponding GaAs-based devices. These higher power densities will result in …
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Synthesis of 1T-Tantalum (IV) Sulfide and observation of charge density wave using scanning tunneling microscopy
… interest and urgency in finding an alternate material system for post-silicon logic and opto-electronic applications, staggering progress have been made in the study of low-dimensional materials. These low-dimensional materials not only help reduce transistor footprint and improve power and …
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Mixed As/Sb and tensile strained Ge/InGaAs heterostructures for low-power tunnel field effect transistors
… the alloy compositions in the source and channel materials. Band alignments at source/channel heterointerface can be well modulated by carefully controlling the compositions of the InxGa1-xAs or GaAsySb1-y. In particular, this research systematically investigate the development and optimization of …
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Design and fabrication of a recycled carrier modulator
… carrier wave. First and foremost, the choice of material was made bearing in mind the implication it would have on the fabrication and operation of the device. Lithium Niobate was chosen given the fact that over the years it has been proven to be a more matured and well understood wave guiding …
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The Linear Growth Rates of Pentaerythritol Crystals
The linear growth rates of the (101) faces of single crystals of Pentaerythritol (Pe) in aqueous solutions have been measured as a function of temperature (10-50°C), and concentration difference (0.25 x 10° acs 2.60 x 10-2 KgPe/Kg Solution) under stagnant conditions in a batch cell. The effect on …
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Optically injected multi-mode semiconductor lasers
… mechanics, thermal and statistical physics, material growth and non-linear mathematics. The laser has been a commercial success in medicine and telecommunication while driving the development of highly optimised devices specifically designed for a plethora of uses. Due to their low-cost and …
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Direct Templating of Semiconductor Nanostructures With Lyotropic Liquid Crystals
Material growth in lyotropic liquid crystals has proven to be a very powerful methodology for the creation of nanoscopic features in mineral phases. Two distinct methodologies were studied---bulk templating and thin film templating. Bulk templating yields a powder of material containing the …
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MoS₂ electronics : technology, high yield circuits and applications
… with the uniformity and yield control in both material growth and device technologies. This thesis addresses issues which are crucial for realizing reliable, and high-yield complex circuits using emerging 2D materials, such as MoS₂: (1) Develop large-area material synthesis and transfer …
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Microscopy study of extreme lattice mismatched heteroepitaxy using interfacial misfit arrays
… lattice-mismatched epitaxy of Sb-based materials on GaAs and Si substrates has attracted considerable attention. However, due to material growth issues such as large lattice mismatch, anti-phase domains and thermal expansion coefficient mismatch, the material relieves strain energy …
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Electrical Characterization of Gallium Nitride Drift Layers and Schottky Diodes
… To meet these requirements, semiconductor material defects, introduced during growth and fabrication, must be minimized. Otherwise, theoretical limits of operation cannot be achieved. In this dissertation, the non-ideal current- voltage (IV) behavior of GaN-based Schottky diodes is …
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Theory and optimisation of metamorphic photonic devices
Metamorphic growth of semiconductor materials – in which a “virtual” substrate with a desired lattice constant is obtained by growing a lattice-mismatched metamorphic buffer layer (MBL) on a conventional substrate such as InP or GaAs – is beginning to attract increasing interest due to its …
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Antimonide-based type-II superlattices for infrared detection
… are its vastly improved electrical properties, material growth quality and cost, and the large number of degrees of freedom in tailoring the band structure to maximize performance at any given wavelength when compared to MCT detectors. However, the performance of T2SLs has been limited due to …
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Understanding the mechanics of growth: A large deformation theory for coupled swelling-growth and morphogenesis of soft biological systems
Understanding the growth of soft biological systems is crucial in a wide range of applications with extensive societal consequences, such as plastic and reconstructive surgery, curbing the growth of tumors and bacterial colonies, tissue engineering of functional vascular grafts, etc. Solid tumors …
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Investigation of InAs/GaSb superlattice based nBn detectors and focal plane arrays
… over larger area and difficulties with the material growth plagues MCT detectors. The quantum efficiency of QWIPs is low and they cannot couple normal incidence photons due to absorption selection rules. The operation temperature of all these detectors is limited to < 200 K in order to …
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Design and Engineering of Carbon Fixing Material Systems
… light, water, oxygen, and physical stress, materials such as coatings, adhesives, and structural composites degrade. Materials fail commonly through the generation and propagation of micro-cracks, with only a miniscule amount of mass degradation often necessitating complete replacement. This …
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Characterization of, and novel architectures for, strained-layer superlattice infrared photodetectors
… are predominantly made of an expensive II-VI material, HgCdTe (mercury cadmium telluride, MCT). A viable alternative class of materials, the III-V type-II superlattices (T2SLs), have been actively studied due to several potential and predicted advantages over MCT. T2SLs offer an easier path to …
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Semiconductor quantum dots for mid-IR light emission
… (NSL), dry-etch, mass-transport, and overgrowth fabrication process. Optically active nano- pillars with diameters as small as 90 nm are fabricated, and narrow linewidth(18 meV) electroluminescence from a fabricated diode structure is observed, with an emission blue-shift of over 37 meV …
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