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 20 for “"Semiconductor films."”.
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Development and optimisation of supercritical fluid deposition of semiconductor films
… with the deposition, and characterisation, of semiconductor thin films and microstructures deposited from a supercritical fluid. Thin films of CdS, GaP, InP, InAs, and Ge were deposited using supercritical CO<sub>2</sub> and CO<sub>2</sub>-solvent mixtures. Ge was deposited into macropores …
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Characterization of epitaxial semiconductor films by scanning tunneling microscopy at ambient pressure
Epitaxial layers grown by molecular beam epitaxy on both silicon and gallium arsenide substrates are exposed by cleaving and studied by scanning tunneling microscopy (STM) at ambient pressure. The cleaved surfaces are prepared for imaging by wet chemical treatments. GaAs/AlGaAs and Si/SiGe …
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High-purity epitaxial growth and characterization of III-V compound semiconductors
… indium gallium arsenide phosphide compound semiconductor films are described. Methods have been developed to improve the purity of both InP and GaAs and to better assess the crystalline homogeneity of the InGaAsP alloy system.
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Time domain measurement of the nonlinear refractive index in optical fibers and semiconductor film
… refractive index n_2 in optical fibers and semiconductor films has been developed. It is based on the time delay two-beam coupling of very intense picosecond laser pulses that have been self-phase modulated in the nonlinear optical medium. The two beams are coupled in a slow responding …
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Nonequilibrium energy transport in heterogeneous nanoscale semiconductors
… these devices are assemblies of nanometer-sized semiconductors, including quantum dots (QD) and organic conjugated polymers. Unlike crystalline semiconductors that are homogenous in energy and space, there exist static and dynamical heterogeneity in nanoscale semiconductors. To control energy …
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Thermo-optic Phase Spectroscopy techniques for multiscale thermal conductance characterization in semiconductor integrated circuits
… a critical challenge in the advancement of semiconductor integrated circuits, particularly with the emergence of three-dimensional (3D) architectures for high-performance applications. This thesis introduces Thermo-optic Phase Spectroscopy (TOPS), a family of non-destructive techniques for …
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Light scattering studies of organic field effect transistors
Organic semiconductors hold a great promise of enabling new technology based on low cost and flexible electronic devices. While much work has been done in the field of organic semiconductors, the field is still quite immature when compared to that of traditional inorganic based devices. More work …
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Monte Carlo Simulation Of Hole Transport And Terahertz Amplification In Multilayer Delta Doped Semiconductor Structures
… dynamics in degenerate valence subbands of cubic semiconductors is developed. All possible intra- and inter-subband scattering rates are theoretically calculated for Ge, Si, and GaAs. A far-infrared laser concept based on intersubband transitions of holes in p-type periodically delta-doped …
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Flux profile modeling using Monte Carlo simulation
… beam Epitaxy (MBE) is a process by which semiconductor films are grown on the substrate by physical vapor deposition of the source material in an ultra high vacuum environment. Spatial variations in flux are a result of the shape of the crucible and the geometry of the growth chamber. In …
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Neutron and x-ray scattering studies of layered solids
… compounds and x-ray scattering studies of semiconductor films and superlattices which were grown by molecular beam epitaxy. For graphite intercalation compounds, these include measurements of the [00 1] longitudinal phonons in the ternary compounds K 1_xRbxCB and KC24 (ND3)x. The results …
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Infrared photoconductive PbTe film processing and oxygen sensitization
… photodetectors, which typically use narrow gap semiconductor materials requiring cryogenic cooling to provide measurable signals above thermally generated noise. Our study investigates one class of photodetectors, namely photoconductive semiconductor films. When embedded within resonant …
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Fabrication of Zinc Nitride Thin Films using RF Magnetron Sputtering Deposition for Optoelectronic Applications
Zinc nitride thin films possess a small optical band gap with direct transition, low resistivity, high mobility and carrier concentration. Therefore, it may be suitable as an optoelectronic material for infrared sensors, smart windows and energy conversion devices. The objective of this work is to …
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Two-dimensional material based layer transfer of thin film devices
The semiconductor industry has mainly centered around silicon-based technology due to its associated cost advantage stemming from the abundance of the element and well-established fabrication infrastructures. However, there exists a plethora of compound semiconductors that offer unique electronic …
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Improved Organic Semiconductor Thin-Film Formation through the Addition of Vibrations to the Solution Shearing Method
… conditions for the solution shearing of organic semiconductors for organic field-effect transistors (OFETs) are investigated. Electrical performance for OFETs is currently still limited by the charge carrier mobility, especially when high fabrication speeds are required. In this work, adaptations …
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Strain-induced self-rolled-up semiconductor micro/nanotubes: Fabrication and characterization
Strain-induced self-rolled-up semiconductor nanotubes are a new type of building block for three-dimensional architectures. Semiconductor nanotubes (SNTs) take advantage of the lattice mismatch between different layers and are formed when the strained semiconductor layers are released from the …
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Characterization of Methyltrimethoxysilane Sol-Gel Polymerization and the Resulting Aerogels.
… interest as a low dielectric constant film for semiconductor devices. The structural development of these materials appears to affect their gelation behaviors and impact their mechanical properties and shrinkage during processing. 29Si solution NMR was used to follow the structural evolution of …
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Novels materials based on 2-dimensional arrays of metal nanoparticles and microparticles
… and develop multi-functional 2-dimensional films based on metal nanoparticles and microparticles via self-assembly combined with other subsequent simple post-processing steps. <br/><br/>The work is based on a general and novel method recently developed by the group in QUB that allows charged …
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Study of silicon-on-insulator multiple-gate MOS structures including band-gap engineering and self heating effects
… Moreover, the thermal conductivity of thin semiconductor films is much lower than that of silicon bulk, due to phonon confinement and boundary scattering. All these aspects cause severe self–heating effects, that detrimentally impact the carrier mobility and therefore the saturation drive …
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A study of hydrogenated nanocrystalline silicon thin films deposited by hot-wire chemical vapour deposition (HWCVD)
… hydrogenated nanocrystalline silicon thin films for solar cells application have been deposited by means of the hot – wire chemical vapour deposition (HWCVD) technique and have been characterised for their performance. It is noticed that hydrogenated nanocrystalline silicon is similar in …
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Predicting the structure and performance of dye-sensitized solar cells by computational methods.
… light-harvesting dye molecules bound to thin semiconductor films of high surface area. Many of the highest-performing DSCs to date incorporate multiple dyes that harvest light from different regions of the solar spectrum in a complementary manner – these are known as cosensitized DSCs. …