Browsing Fakultät für Physik (inkl. GAUSS) by Referee "Hofsäss, Hans Christian Prof. Dr."
Now showing items 1-20 of 56
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Ultra-low Energy Ion Implantation into Graphene
(2023-11-03)This thesis explores the advancement of ultra-low energy (ULE) ion implantation as a method for precisely doping of graphene, with the aim of tailoring its properties for specific applications. The incorporation of impurity ... -
Microstructural Investigations of Epitaxial GaN Films Grown on MgF2 using Transmission Electron Microscopy
(2023-10-27)For the development of novel solar-blind UV multichannel plate detectors planned for applications in astronomy, it would be advantageous to grow GaN acting as the photocathode directly on a typical window material like ... -
UV laser modification of transparent materials for photonic applications
(2023-04-28)Photonic applications have experienced strong growth in recent years. Due to increasing digitalization and automation in all areas of life, further growth of photonics is expected in the future. The broad range of photonic ... -
Investigation of laser-induced structures on metal surfaces produced via two-beam and laser-plasmon interference
(2023-03-15)Periodic surface structures can change the properties of material surfaces. The obtained various functionalities strongly depend on the type of the specific structures. This work deals with the generation of periodic ... -
Proton Beam Writing
(2022-12-16)Proton beam writing (PBW) is a mask-less 3D structuring method that uses a focused, relatively high energy Proton beam, followed by an etching step to create free standing 2D and 3D structures in a large variety of target ... -
Investigation of the Influence of Correlations on Photovoltaic Energy Conversion in Hot Polaron Solar Cells
(2022-08-08)In semiconductor single junction solar cells fundamental limitations are given by the two major intrinsic loss mechanisms: a) inability to absorb photons with energies below the band and b) thermalization of photon energies ... -
Modification of monolayer-thick semiconductors by ultra-low energy ion implantation
(2022-03-08)In this thesis, ultra-low energy (ULE) ion implantation is used to modify 2D materials such as graphene and transition metal dichalcogenides (TMDs). The existing implantation system is improved in two respects. By ... -
Elastic and viscoelastic deformation of glass plates by excimer laser induced stresses and patterned silicon suboxide films
(2021-10-28)A mechanically stressed film can cause a bending of the underlying substrate. Usually, the substrate deforms elastically, but in special cases a plastic or viscous deformation can be observed. Such deformations are mostly ... -
Proximity Effects in Epitaxial Graphene on SiC and their Impact on Atomic-Scale Charge Transport
(2021-10-22)Approaches to exploit the proximity of the two-dimensional material graphene to certain materials in order to specifically tune graphene’s properties start to emerge. However, to turn these approaches into truly beneficial ... -
Defect reaction paths of nickel in float zone silicon controlled by non-equilibrium vacancies
(2020-02-06)This thesis investigates how defect reaction paths of nickel in float zone silicon can be controlled by non-equilibrium vacancy concentrations. Three different aspects have been studied in detail. The temperature-dependent ... -
Hydrogen diffusion and hydride formation in grain boundary rich magnesium
(2019-05-06)In the last decade Magnesium (Mg) has attracted much interest as a storage material for hydrogen in a future hydrogen energy based economy. The reasons are its high reversible hydrogen capacity of up to 7,6 wt% and its ... -
In situ studies on palladium/rutile titanium dioxide exposed to low pressure hydrogen gas environments
(2018-11-12)The interaction of hydrogen gas with the palladium/rutile titanium dioxide model system was investigated with strong focus on the interface and its vicinity. Palladium (Pd) films were deposited on pretreated rutile titanium ... -
Ionenstrahlinduzierte selbst-organisierte Musterbildung auf einfachen Oberflächen Theorie und Experiment
(2018-05-30)In the thesis at hand, ripple pattern formation on amorphous carbon and Si surfaces has been investigated at room temperature during low energy Ne and Ar ion irradiation as a function of the ion incidence angle. Monte ... -
Lichtinduzierte magnetische Defekte in ultradünnen Filmen
(2018-02-09)Topological defects such as domain walls, vortices or skyrmions in magnetic layers, exhibit promising properties which make them especially interesting for future applications in information technology. This work examines ... -
Advanced x-ray multilayer waveguide optics
(2017-09-12)The aim of this thesis is to demonstrate that x-ray waveguide optics can be gen- eralized from a single guiding film to an array of planar waveguides, enabling more complex and controllable phenomena of field propagation ... -
Real-time MRI and Model-based Reconstruction Techniques for Parameter Mapping of Spin-lattice Relaxation
(2017-09-05)Magnetic resonance imaging (MRI) is a non-invasive technique widely used for imaging of humans and animals. It came into existence based on several fundamental inventions made in the 1970s. Since then, MRI has evolved into ... -
Untersuchungen zum Lumineszenzverhalten des Aluminiumnitrids und der Aufbau einer Kurzzeit-Lumineszenz-Spektroskopie-Apparatur
(2017-07-07)This thesis consists of three different parts. In the first part it gives the reader an overview of the published results describing near band-edge as well as defect related luminescence in aluminium nitride, also presenting ... -
A novel approach of immittance-spectra analysis and how it resolves a decade-old deviation of the Frenkel-Poole model
(2017-02-23)Immittance (i.e. a generalisation of all quantities containing identical information as e.g. the impedance) spectroscopy is a well-established and versatile method with a broad range of applications in a wide variety of ... -
Development of InGaN/GaN nanostructures
(2017-02-06)In this work, the mechanisms regulating the selective area growth (SAG) of GaN-based nanostructures have been investigated, under different growth conditions, with the aim of improving the control over the growth of InGaN/GaN ... -
Minimizing thermal conductivity in laser deposited multilayers
(2017-01-26)Heat, light and electricity are three foundation pillars not only of physics, but also of our daily lives. Therefore, these have been studied by scientists for centuries and an always better understanding of the underlying ...