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Showing 1 to 20 of 22 for “"misfit dislocations"”.
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Molecular beam epitaxial growth and characterization of indium antimonide on gallium arsenide
… instead of the common 60$\sp\circ$-type, misfit dislocations at the InSb/GaAs interfaces. The reason for the formation of these misfit dislocations are given. Electrical measurements show that dislocation scattering is an important scattering mechanism in the epilayers. A charged …
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Interfacial structure of delta phase in Inconel 718 and the selection of precipitate habit planes
… with previous reports. A parallel array of misfit dislocations with Burgers vector b=1/6[112̅]<sub>γ</sub>, (designated M1) are always observed lying along the [11̅0] direction. Another array of misfit dislocations appears in some regions of the interface with Burgers vector …
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Structural and thermal properties of graphene - boron nitride superlattice
… and two strain–relieving mechanisms: nanoscale misfit dislocations, and ripples via out–of–plane deformation. For flat superlattices, a critical superlattice pitch (thickness) exists beyond which the interface is decorated by strain–relieving misfit dislocations. For superlattices that can …
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Ultra-High B Doping During Si(1-X)ge(x)(001) Gas-Source Molecular-Beam Epitaxy: A Mechanistic Study of Layer Growth Kinetics, Dopant Incorporation, Electrical Activation, and Carrier Transport
… continues to increase. No B precipitates or misfit dislocations were detected by HR-XRD or TEM. The out-of-plane lattice constant a⊥ decreases linearly with increasing C*B and non-linearly, for CB > C*B . Electrical properties are in good agreement with theoretical values to C*B . When …
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Structural and Morphological Analyses of Aln and Algan Layers
… efficiency of Deep UV LEDs is greatly reduced. Misfit dislocations originated at the interface between AlN epilayer and sapphire substrate is one of the major problems that needs to be effectively studied and overcome.</p> <p>A systematic analysis of various defects present in AlN layers grown …
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Characterization of III-V compound semiconductor heterostructures grown by metalorganic chemical vapor deposition
… occurs in the strained layer superlattice (SLS). Misfit dislocations are found above a certain layer thickness (critical thickness) and the critical thickness is related to the total strain state in SLS. Composition measurements of In$\sb{\rm 1-x}$Ga$\sb{\rm x}$As in SLS using TEM has restrictions …
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Electronic band structure of III-V quantum dots using tight-binding and the k.p approximation
… tunneling spectroscopy (~0.1ev). Strain relaxing misfit dislocations are then considered as the source of this quantitative disagreement; both strain and charging effects of dislocations are investigated computationally, and found to have a large effect on the band alignment. The resulting …
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Strain relaxation mechanism of semiconductor thin films
… it becomes energetically favorable to introduce misfit dislocations above a certain thickness of film growth, which is called a critical thickness. In this case, strain is considered in the continuum elastic sense, defined by the lattice constant of the material. From measurement of the positions …
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Plastic Relaxation of Highly Tensile Strained (100) Ge/InGaAs Heterostructures
… characteristics. We show arrays of misfit dislocations (MDs), which are mostly disassociated, form at the and#949t-Ge/InGaAs interface for and#949t-Ge layers as thin as 15 nm with less than 1% total mismatch. Wedge geometry of plain view transmission electron microscopy (PV-TEM) …
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The role of defects during precipitate growth in a Ni-45wt% Cr alloy
… consists of regular structural ledges and misfit dislocations. No regular defect structure can be found on the habit plane, or broad face, of the lath except for atomic-scale structural ledges. High resolution electron microscopy (HREM) observations show the (12¯1)<sub>f</sub> habit plane …
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Novel structures for lattice-mismatched infrared photodetectors
Using the interfacial misfit (IMF) array growth mode, GaSb p-i-n diodes were grown on Si and GaAs lattice-mismatched substrates by molecular beam epitaxy (MBE) under optimised growth conditions. For the sample grown on Si, an AlSb nucleation layer was used to reduce the occurrence of twinning …
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Investigation of Spinel Ferrite Thin Films for Spintronics Applications
… the formation of antiphase boundaries and misfit dislocations that result in low saturation magnetization and high magnetic saturation field. We show that by combining isostructural substrates with lower lattice-mismatch, as low as 0.06%, and optimum deposition parameters, one can …
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Cross-Sectional Scanning Tunneling Microscopy of Silicon-Based Heterostructures Andp-N Junctions
… on the cleaved surface. This is equivalent to misfit dislocations in bulk strain relaxation. Cross-sectional STM of cleaved ZnS/Si heterostructures reveals that the ZnS layer sandwiched between Si substrate and Si cap layer has a high density of gap states. Possible reasons for the gap states …
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Microscopy study of extreme lattice mismatched heteroepitaxy using interfacial misfit arrays
… the material relieves strain energy through misfit dislocations, defects and often threading dislocations, which vertically propagate to active regions of devices, thus leads to non-radiative recombination and damages device performance. The majority of the work done in this field has been …
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Lattice-mismatched epitaxy of AlInP and characterization of its microstructure and luminescence
… fields from an inhomogeneous distribution of misfit dislocations result in surface roughness and composition fluctuations in lattice-mismatched AlxIn1-xP LEDs. The results obtained in this work will be useful not only in providing control over nanometer-scale structures but also over …
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Grain-Boundary Parameters Controlled Allotriomorphic Phase Transformations in Beta-Processed Titanium Alloys
… the interface as well as presence of new sets of misfit dislocations have been observed in this work.
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Advanced Epitaxy on 2D Materials for Bottom-up Heterointegration with Low-defects and Membrane Production with High-throughput
… manner. Firstly, a unique mechanism of relaxing misfit strain in lattice-mismatched heteroepitaxial systems is observed through the implementation of remote heteroepitaxy, which involves the process of conducting heteroepitaxy on graphene-coated substrates. This approach facilitates spontaneous …
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Molecular beam epitaxy of InAsP graded buffers: From mid-infrared quantum wells to InAs virtual substrates with low threading dislocation density
… GaAs or InP substrates, defects like threading dislocations and misfit dislocations harm the performance of these metamorphic structures. This thesis explores metamorphic growth on InP using InAsP graded buffers grown with molecular beam epitaxy. The first part of this thesis analyzes the …
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Atomic resolution studies of oxide superlattices and ultrathin films
… We also found structural defects, such as misfit dislocations, which leads to increased intermixing over coherent interfaces.
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Heteroepitaxial Germanium-on-Silicon Thin-Films for Electronic and Photovoltaic Applications
… rendering the metamorphic cell sensitive to dislocations. The focus of this dissertation is to investigate heterogeneously integrated 1J GaAs solar cells on Si substrate using germanium (Ge) as an intermediate buffer layer that will address mitigation of defects and dislocations between GaAs …
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