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 46 for “"semiconductor nanostructures"”.
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Semiconductor nanostructures for device applications
… a synthesis and device application of some semiconductors nanostructure. Section 1 layered hexagonal disks of CuO were synthesized on a large scale via low-temperature hydrothermal growth process. The detailed morphological investigations by field emission scanning electron microscopy …
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Charge detection in semiconductor nanostructures
… adjacent to a narrow silicon MOSFET (metal-oxide-semiconductor field-effect transistor), which serves as an integrated charge sensor. We show that the MOSFET can be used to detect charging of the a-Si:H strip. By performing time-resolved measurements of this charging, we are able to measure …
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Correlated exciton dynamics in semiconductor nanostructures
The absorption and dissipation of energy in semiconductor nanostructures are often determined by excited electron dynamics. In semiconductors, one fundamentally important electronic state is an exciton, an excited electron bound to a positively charged vacancy. Excitons can become correlated with …
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Thermal transport in low dimensional semiconductor nanostructures
… using a Green's function method. All ZnO nanostructures studied exhibit semiconducting behavior, with direct bandgap at the Gamma point. The calculated values for the bandgaps were larger than the value of the bandgap of the bulk ZnO. We were able to identify phonon modes in which the …
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Fabrication and characterization of compound semiconductor nanostructures
Semiconductor optoelectronic devices are expected to have their performance improved by the use of quantum confinement in the active region with sizes in the range of tenths of nanometers. The decrease in volume of the active region and the modification in the density of states in quantum …
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Energetics and Dynamics in Quantum Confined Semiconductor Nanostructures
<p>The ability to tune the band-gap energies of semiconductor quantum dots, nanoplatelets, and quantum wires, their significant absorption cross sections, and high photoluminescence quantum yields make these nanostructures promising moieties for use in optoelectronic devices, solar concentrators, …
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Shadow mask assisted heteroepitaxy of compound semiconductor nanostructures
… is a technique enabling selected area epitaxy of semiconductor heterostructures through shadow masks. The objective of this work was the development of the SMMBE technique for the reliable fabrication of compound semiconductor nanostructures of high structural and optical quality. In order to …
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Optically detected terahertz resonance spectroscopy of semiconductor nanostructures
… various terahertz (THz) resonances in semiconductors. We use a THz QCL, of an appropriate frequency, operating in the close vicinity of the sample. Due to the small size of the QCLs, we can mount them on the sample holder of the magnet, which allows focusing of the THz beam onto the …
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Direct Templating of Semiconductor Nanostructures With Lyotropic Liquid Crystals
… superlattices of CdS, CdSe, ZnS, and CdTe. The semiconductor growth process copied the symmetry and characteristic dimensions of the original hexagonal mesophase by avoiding growth of mineral within regularly spaced hydrophobic regions. The final product was a superlattice structure in which a …
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Single electron charging and quantum effects in semiconductor nanostructures
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1993.
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Auger-mediated processes and photoluminescence in group iv semiconductor nanostructures
Group IV semiconductors (Si, Ge) are inefficient light emitting materials due to their indirect bandgap structure. Nanostructures of Si, Ge, and SiGe however, have shown relatively high photoluminescence (PL) quantum efficiency (QE) at low carrier concentrations. At higher carrier concentrations, …
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Modelling of semiconductor nanostructures : electronic properties and simulated optical spectra
III-V semiconductor nanostructures are widely used in optoelectronic devices (e.g. lasers and detectors) in the visible (0.4-0.8 μm), near-infrared (0.8-3 μm), mid-infrared (3-5 μm) and far-infrared (> 8 μm) wavelength ranges, with great potential for high performance and high temperature …
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On the Concepts of Resistance and Capacitance in Semiconductor Nanostructures
… concepts of capacitance and resistance to semiconductor nanostructures are investigated. In particular, the combination law for the conductances of two parallel mesoscopic constrictions is discussed, reaching the conclusion that, as long as the bifurcation into parallel constrictions takes …
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Metal-assisted chemical etching of semiconductor nanostructures for electronic applications
… anisotropic high aspect ratio micro- and nanostructures with the absence of ion induced surface damage has attracted tremendous attention in device applications such as light emitting diodes, solar cells, biosensors, supercapacitors, thermo-electrics, and 2.5 D and 3D transistors. The …
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Interaction of Terahertz Radiation with Semiconductor Nanostructures and Quantum Systems
… with various structures and materials, including semiconductor nanostructures and quantum systems. This is the topic that this thesis is dedicated to. In this work, I demonstrate a highly sensitive THz detector based on a new physical principle of operation which was called the "in-plane …
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Quantum spins in semiconductor nanostructures: Hyperfine interactions and optical control
… and applications of two of such systems: Semiconductor quantum dots and topological insulators. The first part of the dissertation is devoted to the study of semiconductor quantum dots as candidates for quantum information storage and sources of single-photon emission. The spin of the …
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Quantum information processing with geometric phases, cavity magnonics, and semiconductor nanostructures
… coherent control, we examine the use of semiconductor-based nanostructures, notably electrostatically defined quantum dots in silicon-germanium heterostructures for quantum computing. By considering such a structure in the presence of a slightly tilted silicongermanium interface, we …
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Theoretical analysis of electronic properties and transport phenomena in semiconductor nanostructures
Quantized semiconductor structures are presently under investigation for their physical properties and their potential for device applications. The theoretical modeling of these structures is particularly important for complementing fabrication technology due to the predictive capabilities of …
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Correlation of Photocatalytic Activity with Band Structure of Low-dimensional Semiconductor Nanostructures
… solar fuel. The development of effective semiconductor photocatalysts to obtain efficient photocatalytic activity is the key objective. However, two critical reasons prevent wide applications of semiconductor photocatalysts: low light usage efficiency and high rates of charge …
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