Browsing Fakultät für Physik (inkl. GAUSS) by Advisor & Referee "Jooß, Christian Prof. Dr."
Now showing items 1-20 of 39
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Grenzflächen- und Verspannungseffekte in La₁₋ₓSrₓMnO₃-Dünnschichten
(2024-12-19)In this dissertation, strain and interface effects on La₁₋ₓSrₓMnO₃ (LSMO) thin films with doping levels 0 ≤ x ≤ 0.6 are investigated by Raman spectroscopy and surface-enhanced Raman spectroscopy (SERS). For undoped LaMnO₃, ... -
Bringing Order to the Framework: Nanoscale Charge Transport Characterization of MOFs and COFs
(2024-10-22)Reticular chemistry, the synthesis of highly ordered, porous, crystalline networks with a previously identified target structure, has given rise to various classes of open framework materials, including the best-known ... -
Magneto-thermal conductivity of perovskite manganite films and exchange-spring coupled superlattices
(2024-02-21)In this thesis, thin colossal magnetoresistive perovskite manganite films and superlattices forming an exchange spring magnet were studied regarding their magneto-thermal conductivity. Using the metalorganic aerosol ... -
Elektronenmikroskopische Untersuchung des Einflusses elektrischer Felder auf das Sinterverhalten von Oxidkeramiken
(2023-11-09)Despite the wide application potential of flash sintering for processing ceramic materials, the physical origins of the effect remain unclear. Therefore, the primary objective of this work is to gain a deeper understanding ... -
Electronic and Structural Properties of Heterojunctions in Solar Cells studied by In-situ and Analytical Transmission Electron Microscopy
(2023-11-03)The overarching goal of this dissertation is to investigate new principals to increase photovoltaic efficiency. In this context, three topics are presented, one concerning the application of carrier selective contacts ... -
Phase-Dependent Energy Dissipation Processes in La0.7Sr0.3MnO3 and (La0.6Pr0.4)0.7Ca0.3MnO3 after an Ultrashort Optical Excitation
(2023-08-31)La0.7Sr0.3MnO3 (LSMO) and (La0.6Pr0.4)0.7Ca0.3MnO3 (LPCMO) are perovsikte manganites which both show a ferromagnetic-to-paramagnetic phase transition. Interestingly, the development of the new phase when crossing the ... -
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 ... -
In-situ Environmental Transmission Electron Microscopy Investigation of Perovskite Oxide Thin Films During Electrochemical Oxygen Evolution Reaction.
(2022-07-21)Despite many theoretical and experimental efforts to find active catalysts in oxygen evolution reaction (OER), the mechanism for high activity and long-term OER stability remains elusive. Catalyst-electrolyte interface ... -
Spektrale Kontrolle von elastischer Dynamik und Wärmetransport in periodischen Nanostrukturen
(2021-11-26)In this dissertation I show theoretical and experimental investigations of phononic heat transport. In the first part of the thesis, I use femtosecond pump-probe spectroscopy to demonstrate how a wedge-shaped transducer ... -
Kationordnung und Grenzflächeneffekte in stark korrelierten Elektronensystemen
(2021-10-05)The work is about cation ordering and interface mechanism in strongly correlated electron systems -
Structural and Electronic Investigation of Strongly Correlated Transition Metal Oxide Perovskite Thin Films and Interfaces using In-situ Transmission Electron Microscopy
(2021-09-09)Discussing the necessity as well as possible details of global strategies to reduce and eventually eliminate the anthropogenic climate change (ACC) is a delicate matter, which easily leads to statements based on ... -
Scanning Tunneling Spectroscopy of Subsurface Non-Magnetic Impurities in Copper
(2021-09-06)In this thesis, single non-magnetic Ge and Ag impurities buried in the bulk metal Cu are studied to characterize their scattering properties as well as the electronic structure of the host. This is possible by analyzing ... -
Ultrafast transmission electron microscopy of a structural phase transition
(2021-08-09)High hopes are placed on materials with tunable properties and excitations for future applications in energy conversion devices. Functionality of devices, however, not only arises from the properties of individual materials ... -
In-Situ Environmental TEM Studies of Electro- and Photo-Electrochemical Systems for Water Splitting
(2021-02-22)This thesis presents studies on the structure and stability of materials for electrochemical water splitting and the changes in the active state. The stability of a TiO2 protection layer on a silicon multi-junction is ... -
First-principles calculations of polaronic correlations and reactivity of oxides: manganites, water oxidation and Pd/rutile interface
(2019-05-28)The electronic, magnetic and atomic structure of Pr1−xCaxMnO3 have been investigated using combination of first-principles calculations, x-ray photoelectron spectroscopy (XPS), x-ray absorption spectroscopy (XAS), and ... -
Correlation between Thermal Transport Mechanisms and Microstructure of Epitaxially Grown (Sb1-xBix)2Te3 Thin Films
(2019-05-23)This thesis experimentally studies the mechanisms associated with the very low lattice thermal conductivities of the ternary van der Waals layered compound (Sb1-xBix)2Te3. This compound presently constitutes one of the ... -
Implementation and quantification of scanning transmission EBIC experiments for measuring nanometer diffusion lengths in manganite-titanite p-n heterojunctions
(2019-01-08)The scanning transmission electron beam induced current (STEBIC) approach to measure charge carrier diffusion lengths in the nanometer range in 3rd generation photovoltaics devices is presented, evaluated and applied to ... -
The study of magnetic and polaronic microstructure in Pr1-xCaxMnO3 manganite series
(2018-09-21)Manganites have been studied intensively due to their extraordinary properties: colossal magnetoresistance and ferroelectricity. The inhomogeneities present in certain regions of the phase diagram are believed to be ... -
Structure and photovoltaic properties of strongly correlated manganite/titanite heterojunctions
(2018-08-21)In the present thesis the photovoltaic (PV) effect in strongly correlated manganite/titanite heterostructures is investigated. As a model system thin films of Pr$_{1-x}$Ca$_{x}$MnO$_{3}$ (PCMO) were deposited on single ... -
Transmission electron microspy studies of ion migration in resistive switching platinum-manganite heterostructures
(2018-04-16)Non-volatile resistance change under electric stimulation in many metal-oxides is a promising path to next generation memory devices. However, the underlying mechanisms are still not fully understood. In this study ...