A5069716647- Surface and Thin Film Phenomena
- Semiconductor Quantum Structures and Devices
- Semiconductor materials and devices
- GaN-based semiconductor devices and materials
- Semiconductor materials and interfaces
- Molecular Junctions and Nanostructures
- Advanced Chemical Physics Studies
- Chalcogenide Semiconductor Thin Films
- ZnO doping and properties
- Quantum Dots Synthesis And Properties
- Electron and X-Ray Spectroscopy Techniques
- Quantum and electron transport phenomena
- Ga2O3 and related materials
- Spectroscopy and Quantum Chemical Studies
- Child and Adolescent Psychosocial and Emotional Development
- Advanced Semiconductor Detectors and Materials
- Solid-state spectroscopy and crystallography
- Optical Coatings and Gratings
- Acoustic Wave Resonator Technologies
- Force Microscopy Techniques and Applications
- Magnetic properties of thin films
- Metal and Thin Film Mechanics
- Cancer Research and Treatments
- Copper-based nanomaterials and applications
- Advanced Materials Characterization Techniques
Technische Universität Berlin
2011-2025
Leibniz Institute for Analytical Sciences - ISAS
2015-2024
University of Potsdam
2007-2020
University of Würzburg
2014-2018
Janssen (Belgium)
2013-2018
Centre Hospitalier Universitaire de Liège
2018
Humboldt-Universität zu Berlin
2017
Leibniz Institute for Neurobiology
2010-2015
Otto-von-Guericke University Magdeburg
2012-2013
Paderborn University
2013
We have recently proposed a macromolecular prodrug strategy for improved cancer chemotherapy based on two features (Kratz, F.; et al. J. Med. Chem 2000, 43, 1253−1256.): (a) rapid and selective binding of thiol-reactive prodrugs to the cysteine-34 position endogenous albumin after intravenous administration (b) release albumin-bound drug in acidic environment at tumor site due incorporation an acid-sensitive bond between carrier. To investigate this therapeutic greater depth, four...
This paper discusses the fundamentals, applications, potential, limitations, and future perspectives of polarized light reflection techniques for characterization materials related systems devices at nanoscale. These include spectroscopic ellipsometry, polarimetry, reflectance anisotropy. We give an overview various ellipsometry strategies measurement analysis nanometric films, metal nanoparticles nanowires, semiconductor nanocrystals, submicron periodic structures. show that is capable more...
The interplay between band gap renormalization and filling (Burstein-Moss effect) in n-type wurtzite GaN is investigated. For a wide range of electron concentrations up to $1.6\ifmmode\times\else\texttimes\fi{}{10}^{20}\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$ spectroscopic ellipsometry photoluminescence were used determine the dependence energy Fermi edge on density. dominating effect an density about...
The optical properties of copper and silver bulk crystals with atomically clean surfaces have been determined experimentally interpreted in terms ab initio band structure calculations. dielectric functions are evaluated from spectroscopic ellipsometry data taken ultrahigh vacuum (UHV) the spectral range 2.5--9.0 eV (at room temperature). corrected for surface roughness using results ex situ atomic force microscopy (AFM). Significant differences detail amplitudes line shape attributed to...
EphB receptors and their ephrinB ligands play a key role in the formation of regular vascular system. Recent studies have also shown involvement Eph/ephrin interactions malignant tumor progression angiogenesis. We generated soluble monomeric EphB4 (sEphB4)-expressing A375 melanoma cells to study effect dominant negatively acting sEphB4 on growth Soluble EphB4-expressing tumors grown subcutaneously nude mice show dramatically reduced compared control tumors. The proliferative capacity...
EphB receptors and their ephrinB ligands play a key role in the formation of regular vascular system. Recent studies have also shown involvement Eph/ephrin interactions malignant tumor progression angiogenesis. We generated soluble monomeric EphB4 (sEphB4)-expressing A375 melanoma cells to study effect dominant negatively acting sEphB4 on growth Soluble EphB4-expressing tumors grown subcutaneously nude mice show dramatically reduced compared control tumors. The proliferative capacity...
The reflectance anisotropy has been calculated by microscopic tight-binding theory for various configurations of the As-rich GaAs(100) $c(4\ifmmode\times\else\texttimes\fi{}4)$ and $(2\ifmmode\times\else\texttimes\fi{}4)$ reconstructions, based on precise atomic coordinates from ab initio total-energy minimization. comparison to experimental in combination with scanning tunneling microscopy low energy electron diffraction allows one identify correlations between structural units optical...
The irradiation-induced reduction of electrochemically grafted nitrobenzene films on Si(111) was monitored by high-resolution photoelectron spectroscopy. experiments were performed using synchrotron soft X-ray irradiation at the BESSY II facility. evolution different chemical species as a function time. Careful fitting Si2p, C1s, N1s, and O1s core level spectra allowed us to follow this process in detail determine constants growth decay specific components. changes caused secondary electron...
The pH-dependent switching of a poly(acrylic acid) (PAA) polyelectrolyte brush was investigated in situ using infrared spectroscopic ellipsometry (IRSE). synthesized by "grafting to" procedure on silicon substrate with native oxide layer. overall thickness the PAA dry state ∼5 nm. Reversible polymer studied at titration from pH 2 to 10 and back steps 1 unit. process observed monitoring characteristic vibrational bands carboxylic groups molecules. Decreasing C═O band amplitude arising COO−...
The intrinsic anisotropic optical properties of wurtzite AlN are investigated in absorption and emission. Full access to the anisotropy response hexagonal material is obtained by investigating $(1\overline{1}00)$ plane a high-quality bulk crystal allowing electric field $\mathbf{E}$ polarization perpendicular ($\mathbf{E}\ensuremath{\perp}\mathbf{c}$) parallel ($\mathbf{E}\ensuremath{\parallel}\mathbf{c}$) axis $\mathbf{c}$. Spectroscopic ellipsometry yields ordinary...
Background Clock genes govern circadian rhythms and shape the effect of alcohol use on physiological system. Exposure to severe negative life events is related both heavy drinking disturbed rhythmicity. The aim this study was 1) extend previous findings suggesting an association a haplotype tagging single nucleotide polymorphism PER2 gene with patterns, 2) examine possible role for interaction stress in hazardous drinking. Methods Data were collected as part epidemiological cohort outcome...
$\ensuremath{\beta}\ensuremath{-}{\mathrm{Ga}}_{2}{\mathrm{O}}_{3}$ is a transparent wide-band-gap semiconductor that has attracted considerable interest in recent years due to its suitable electrical conductivity and transparency the ultraviolet spectral region. In this work we investigate electronic properties of near valence-band-edge region for semiconducting (100) bulk single crystals using core-level photoelectron spectroscopy ab initio theory within framework density functional...
We present a comprehensive overview of the optical properties zinc-blende GaN. By variety different methods, such as temperature-dependent photoluminescence, photoluminescence excitation spectroscopy, photoreflectance, and ellipsometry, we investigate its emission absorption related characteristics. The sample under study is nearly strain-free epitaxial layer grown on freestanding cubic SiC. light-hole/heavy-hole exciton was found at $3.271\phantom{\rule{0.16em}{0ex}}\mathrm{eV}$...
Density-functional-theory calculations are combined with many-body perturbation theory in order to elucidate the geometry, electronic, and optical properties of $wz\ensuremath{-}\mathrm{GaN}(1\overline{1}00$) surface, i.e., so-called $m$-plane. The absorption reflection anisotropy related electronic transitions between surface states identified by comparison measured data covering transition energies from 2.4 up 5.4 eV. Our results show a relaxation mechanism consistent electron counting...
A detailed analysis based on first-principles calculations with self-energy corrections is combined photoemission spectroscopy to determine the origin of features observed in reflectance anisotropy (RAS) at semiconductor surfaces. Using $\mathrm{InP}(001)(2\ifmmode\times\else\texttimes\fi{}4)$ surface as a model case we obtain quantitative agreement between slab and low-temperature RAS measurements. We find contributions signal related either directly states or transitions perturbed bulk...
Abstract This paper reviews the structural properties of ternary chalcopyrite absorbers for solar‐cell device applications studied by Raman Spectroscopy. mode assignment in CuGaSe 2 is reviewed according to results previous and present IR spectroscopic studies. The compositional dependence modes, particular, composition dependent frequency shift A 1 ‐mode, suggested analysis film structure. Order disorder effects are discussed with reference excitation phonon modes assigned Cu–Au ordered...
Aims: To investigate whether concurrent alcohol and tobacco use during early adolescence characterizes a subgroup that differs from users of one substance only regarding several risk factors for later problems. Methods: Participants were prospective longitudinal cohort study 384 children at psychopathology, with the majority being born obstetric complications psychosocial adversities. Assessments adolescent drug consumption related intrapersonal characteristics obtained age 15. Results:...