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.
Results
Showing 1 to 20 of 85 for “"Lattice Mismatch"”.
-
Investigation of lattice mismatch in rhenium containing nickel-base superalloys
… three techniques for measuring gamma/gamma prime lattice mismatch were examined on two alloys, each of which had two different ageing heat treatments, i.e. standard age and overaged. Each alloy contained a different Re content so that the effect of this element on lattice mismatch also could be …
-
The Characterization of Liquid Phase Epitaxial Indium-Gallium - Arsenide - Phosphide and Indium-Gallium - Arsenide
… to produce high quality epitaxial layers. The lattice mismatch of these layers with respect to the underlying InP substrate was determined by X-ray diffraction, and the energy gap was obtained by optical spectrophotometer transmission measurements. The distribution coefficients for the growth …
-
Selective epitaxial growth techniques to integrate high-quality germanium on silicon
… poses many engineering challenges, ranging from lattice mismatch, to thermal expansion coefficient mismatch, to non-planar morphological evolution. The lattice mismatch between Ge and Si often leads to a high density of threading dislocations. These dislocations, if not reduced, propagate through …
-
Silicon-germanium nanowire heterojunctions: Optical and electrical properties
… the nanowire axial heterojunctions, especially lattice mismatched heterojunctions. Si and Ge have a considerable lattice mismatch of ~ 4.2% as well as a mismatch in the coefficient of thermal expansion, and the formation of a Si_{1-x}Ge_x transition layer at the heterointerface creates a …
-
Integration of III-V optical devices and interconnects on Si using SiGe virtual substrates
… However, materials compatibility issues such as lattice mismatch, polar-on-non-polar epitaxy, and thermal mismatch make the direct growth of high quality GaAs-based material on Si difficult. However, with the use of SiGe virtual substrates, Si substrates that have the Ge lattice constant, this …
-
Cs-Pb-Br Core-shell Perovskite Microcrystals for Stability Improvement
… configuration. This efficiently corrects the lattice mismatch between the core and shell. Because of its indirect band gap, photoluminescence (PL) intensity, water resistance, and minimum lattice mismatch with CsPbBr3 NCs, 0D Cs4PbBr6 and 2D CsPb2Br5 perovskite materials are thought to be …
-
Scanning Tunneling Microscopy Studies of Cluster Diffusion in a Highly Mismatched system:Copper on Silver(111)
… and growth and the late stages for a highly mismatched system, Cu on Ag(111). In particular, activation energies and prefactors for cluster diffusion are measured directly by tracking cluster motion with atomic precision at multiple temperatures to determine the temperature dependence of hop …
-
Scanning Tunneling Microscopy Studies of Cluster Diffusion in a Highly Mismatched System: Copper on Silver(111)
… and growth and the late stages for a highly mismatched system, Cu on Ag(111). In particular, activation energies and prefactors for cluster diffusion are measured directly by tracking cluster motion with atomic precision at multiple temperatures to determine the temperature dependence of hop …
-
Structural and thermal properties of graphene - boron nitride superlattice
… such as the graphene - boron nitride (C-BN) superlattices. C-BN superlattices with regular ordered subdomains of graphene and boron nitride have recently been synthesized and characterized as a potential candidate for optoelectronic and thermoelectric devices. However, detailed structure of the …
-
Remote Epitaxy by In-Situ Grown BN and InGaN Strain Relaxation
… to be able to relax the misfit strain caused by lattice mismatch. For example, the large lattice mismatch between the high indium content indium gallium nitride (InGaN) and the GaN substrate impedes the efficiency of the InGaN based red micro-LED. In the last part, relaxed high indium content …
-
Integration of GaAsP alloys on SiGe virtual substrates for Si-based dual-junction solar cells
… Our results showed that despite the low lattice-mismatch conditions at the P-rich end of the GaAsP alloy spectrum, it was difficult to achieve thin films low defect density. We proceeded to focus on the integration of GaAsP alloys on Si via the use of SiGe compositionally graded layers. …
-
X -Ray Studies of Metal Thin Film Growth on Semiconductors
… discrete thicknesses present, despite the large lattice mismatch between Ag and Ge. In some cases, the film thickness is nearly atomically uniform. The results are discussed in connection with recent models and theories of electronic effects on the growth of ultrathin metal films.
-
Properties and device applications of silicon and silicon-germanium nanostructures with different dimensions
… nanostructures are demonstrated despite the 4% lattice mismatch between Si and Ge. The lattice mismatch-induced strain is sufficiently relaxed through the designed, cluster morphology, or nanowire (NW) structures. Future device applications of these nano structures require complete understanding …
-
Effects of AG on structural and magnetic properties of FePt thin films
… layer in FePt HAMR system because of its close lattice mismatch with FePt and good thermal conductivity.
-
Design, growth and optimization of 2-μm InGaSb/AlGaSb quantum well based VECSELs on GaAs/AlGaAs DBRs.
… distributed Bragg reflectors (DBRs), grown latticematched on GaSb substrates. In this work the ability to grow such antimonide VECSEL structures on GaAs substrates is explored. The growth of such III-Sb VECSELs on GaAs substrates is non-trivial due to the 7.78% lattice mismatch between the …
-
Wafer bonding for monolithic integration of Si CMOS VLSI electronics with III-V optoelectronic devices
… GaAs to Si, have been developed to overcome lattice mismatch in order to integrate optoelectronic and Si devices. However, the thermal expansion differences between these materials continues to be a limitation in using either of these approaches. After recognizing that Si devices, such as …
-
GaInN/GaN Schottky Barrier Solar Cells
… material quality issues stemming from the large lattice mismatch between its binary endpoints and questionable range of p-type doping has thus far prevented realization of high efficiency solar cells. Nonetheless, amorphous and multi-crystalline forms of GaInN have been theorized to exhibit a …
-
Enhancement Of Magnetic Vortex Pinning by APCs with Coherent BZO 1D-APC/YBCO Interface
… column around the BZO 1D-APCs due to the large lattice mismatch of ~7.7% between the BZO (3a=1.26 nm) and YBCO (c=1.17 nm). In this thesis, I report a dynamic lattice enlargement approach on the tensile strained YBCO lattice during the BZO 1D-APCs growth to induce c-axis elongation of the YBCO …
-
Substrate Impurity Incorporation Mitigation for Improved AlGaN/GaN-ON-Si RF Performance
… channel. Moreover, the presence of significant lattice mismatch and thermal mismatch between the AlN nucleation layer and Si leads to a very large threading dislocation density (TDD) within the AlN layer thereby creating a leakage path, significant electron scattering, and charge carrier trap …
-
Mechanics Analysis of Semiconductor Nanotube Formation Driven By Residual Mismatch Strain
… on the residual stress in the system due to a lattice mismatch between each layer as the driving force for formation from a flat plate into a tube. A recent technique utilizing a photolithographic patterning process has allowed for large scale manufacturability of these tubes. However, when …
Page 1 of 5