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 33 for “"Al-Ga"”.
-
Wachstum und Realstruktur von epitaktischen (Al,Ga)N-Schichten
… der Einfluss der Wachstumsparameter auf die Realstruktur von binären GaN-, AlN- und ternären (Al,Ga)N-Schichten untersucht. Die Abscheidung der Schichten erfolgte heteroepitaktisch mittels Molekularstrahlepitaxie (MBE) auf den Substraten Al2O3 (0001), Si (111) und 6H-SiC (0001). <br>Die …
-
Understanding the Corrosion of Low-Voltage Al-Ga Anodes
Aluminum is an attractive metal for use as an anode in the cathodic protection of steels in seawater due to its low cost and high current capacity. Zinc is often used for its ability to readily corrode, but it has a low current capacity and it operates at very negative voltages, leading to hydrogen …
-
Charakterisierung und Optimierung von (Al, Ga)N-basierten UV-Photodetektoren
… geometry on the electro-optic properties of AlGaN-based metal-semiconductor-metal photodetectors (MSM PD) was investigated. The focus was on the realization of Schottky-type MSM PD suitable for photodetection below wavelengths of 300 nm with a high external quantum efficiency (EQE). First, …
-
Supersilyltriel-Clusterverbindungen R*mEn (R* = SitBu3; E = Al, Ga, In, Tl)
… Clusterverbindungen RmEn, aus Borhomologen E, also von polyedrischen Verbindungen aus den schweren Trielen Aluminium bis Thallium. Sie stellen ausgeprägte Elektronenmangelverbindungen dar.
-
Al-Ga Sacrificial Anodes: Understanding Performance via Simulation and Modification of Alloy Segregation
… must withstand the corrosive effects of salt water in a way that is low cost, reliable, and environmentally friendly. Aluminum satisfies these conditions, and would be a good choice for a sacrificial anode to protect steel structures if it did not passivate. However, various elements can …
-
MOVPE growth and characterization of Al(Ga)N and InAlN/AlGaN quantum wells for UV LED applications
The study of III-nitride materials (InN, GaN and AlN) gained huge research momentum after breakthroughs in the production light emitting diodes (LEDs) and laser diodes (LDs) over the past two decades. Last year, the Nobel Prize in Physics was awarded jointly to Isamu Akasaki, Hiroshi Amano and …
-
Existenzbereiche und physikalische Eigenschaften metallreicher Perowskite (SE3X)M (SE = Seltenerd-Metall; X = N, O; M = Al, Ga, In, Sn)
Die Existenz metallreicher Perowskite der Zusammensetzung (SE3X)M (X = O, N; SE = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Er, Ho, Tm, Lu; M = Al, Ga, In, Sn) wurde untersucht. Die Charakterisierung der Proben erfolgte mit Röntgenpulverdiffraktometrie und Elementaranalysen (O und N). Oxide (SE3O)Al mit SE = …
-
On the synthesis, characterization, and magnetization of Ln-M-X (Ln = lanthanide; M = Ti-Cr, Cu, Mo, Pd; X = Al, Ga) intermetallics
… presented herein was to grow single crystals of Ln-M-X (Ln = lanthanide; M = Ti-Cr, Cu, Mo, Pd; X = Al, Ga) intermetallic compounds and to characterize their crystal structures and physical properties. Overall, the flux growth technique facilitated a detailed analysis of previously known …
-
Analysis of the Indium Gallium Arsenide/aluminum Gallium Arsenide Modulation-Doped Field Effect Transistor
… are the growth and characterization of (In,Ga)As/(Al,Ga)As modulation-doped field-effect transistors (MODFETs). The use of a thin strained layer of (In,Ga)As for the current-carrying channel takes advantage of the superior transport properties of this material while maintaining high crystal …
-
Layer disordering and aluminum-gallium interchange in aluminum-gallium arsenide - gallium-arsenide quantum well heterostructures
In the experiments described here, Al$\sb{\rm x}$Ga$\sb{\rm 1-x}$As-GaAs superlattice and quantum well heterostructure (QWH) crystals have been used as test vehicles to study Al-Ga interdiffusion. The data demonstrate that Al-Ga interchange is strongly influenced by the interdependence of the …
-
Wavelength Modification by Thermal Annealing and Stripe Geometry Definition by Impurity-Induced Disordering in Quantum-Well Laser Diodes (Diffusion, Gallium-Arsenide, Iii-v Semiconductors)
The effects of thermal annealing ((TURN)900(DEGREES)C) on quantum-well laser diode properties are investigated. The shift to higher energies caused by inter-diffusion of Al and Ga at the quantum-well interfaces in modeled by a modified Poschl-Teller potential. The interdiffusion coefficient …
-
Elektrische Spininjektion in GaAs LEDs
… Arbeit war die elektrische Spininjektion in Halbleiter zu erforschen und Methoden zu deren Realisation zu entwickeln. Hierzu wurden in dieser Arbeit III-V und II-VI Halbleiterheterostrukturen mit Hilfe von Photolumineszenz-, Elektrolumineszenz- und Anregungsspektroskopie untersucht. Die …
-
Electronic structure and optical properties of layered ternary transition-metal carbides and nitrides
The electronic structure and optical properties of Ti3AC2 (A=Al, Si, Ge), Ti2AC (A=Al, Ga, In; Si, Ge, Sn; P, As; S), Ti2AlN, M2AlC (M=V, Nb, Cr) and Tan+1AlCn (n=1~4) have been studied using first-principles orthogonalized linear combination of atomic orbitals (OLCAO) method. These layered ternary …
-
Analysis of Light Extraction Efficiency Enhancement for Deep Ultraviolet and Visible Light-Emitting Diodes with III-Nitride Micro-Domes
III-nitride (In, Al, Ga-N) semiconductors are considered as wide-bandgap materials that have promising applications in the next generation of lighting technology such as ultraviolet (UV) / visible light-emitting diodes and laser diodes. The limitation occurred in light extraction efficiency of …
-
Herstellung von Bauelementen für Spininjektionsexperimente mit semimagnetischen Halbleitern
Im Rahmen dieser Arbeit sollten Halbleiterheterostrukturen mit semimagnetischen II-VI-Halbleitern hergestellt werden, mit denen Experimente zum Nachweis und der Erforschung der Spininjektion in Halbleiter durchgeführt werden. Hierzu sollten optische und Transportexperimente dienen. Zur Polarisation …
-
Surface ordering of MBE grown 001 gallium(05) aluminum(05) arsenic: A theoretical study
The surface kinetics of MBE growth of 001 {dollar}Ga\sb{x}Al\sb{1-x}As{dollar} is studied theoretically using the stochastic model which is based on the master equation approach and random distribution approximation. The kinetic processes included in the model are adsorption and surface migration. …
-
A phase field model for the gallium permeation of aluminum grain boundaries
… are important features found in materials. Material properties such as fracture toughness, corrosion susceptibility and high temperature creep are influenced by grain boundary physics. The structure of grain boundaries affects their properties. In this thesis, we have developed a …
-
ELECTRONIC MATRIX ISOLATION SPECTROSCOPIC STUDIES OF METAL ATOM PHOTOCHEMISTRY
This dissertation presents the results of chemical research efforts directed in three areas: (1) the final design of an ultraviolet-visible absorption and emission matrix isolation apparatus is described, (2) by employing this apparatus, molecular scale interactions of the 1:1 metal-water adduct …
-
Metalorganic Chemical Vapor Deposition of High-Performance GaAs-Based Quantum-Dot Lasers
… dieser Arbeit wurde eine Verbesserung der metallorganischen Gasphasenepitaxie (MOCVD) neuartiger GaAs-basierter Halbleiter-Laserstrukturen mit selbstorganisierten InGaAs/GaAs Stranski-Krastanow-Quantenpunkten (QPen) als aktivem Medium hinsichtlich der Lasereigenschaften erzielt. Die …
Page 1 of 2