A5019375520- Molecular Junctions and Nanostructures
- Graphene research and applications
- Surface and Thin Film Phenomena
- Material Dynamics and Properties
- Sports Analytics and Performance
- Surface Chemistry and Catalysis
- Smart Grid Energy Management
- Aviation Industry Analysis and Trends
- Physics of Superconductivity and Magnetism
- 2D Materials and Applications
- Synthesis and Properties of Aromatic Compounds
- Pickering emulsions and particle stabilization
- Advanced Chemical Physics Studies
- Complex Systems and Decision Making
- Quantum and electron transport phenomena
- Phase Equilibria and Thermodynamics
- Complex Network Analysis Techniques
- Theoretical and Computational Physics
- Financial Markets and Investment Strategies
- Complex Systems and Time Series Analysis
- Diamond and Carbon-based Materials Research
- Digital Innovation in Industries
- Stock Market Forecasting Methods
- Corporate Governance and Management
- Stochastic processes and statistical mechanics
Jülich Aachen Research Alliance
2016-2022
Forschungszentrum Jülich
2016-2022
RWTH Aachen University
2020
Grunberger Diabetes Institute
2019
Stadtwerke Jülich (Germany)
2019
Johannes Gutenberg University Mainz
2011-2015
TU Bergakademie Freiberg
2013
Helmholtz-Zentrum Dresden-Rossendorf
2011
Karlsruhe Institute of Technology
2007-2008
Karlsruhe University of Education
2007
We investigate the structural and electronic properties of nitrogen-doped epitaxial monolayer graphene quasifreestanding on $6H\text{\ensuremath{-}}\mathrm{SiC}(0001)$ by normal incidence x-ray standing wave technique angle-resolved photoelectron spectroscopy supported density functional theory simulations. With location various nitrogen species uniquely identified, we observe that for same doping procedure, support, consisting substrate interface, strongly influences as well resulting doped...
We studied the crystallization kinetics of homogeneous bulk as well heterogeneous wall in a colloidal hard sphere model system within fluid crystal coexistence region. Using time resolved static light scattering and Bragg microscopy we determined several parameters characterizing process (induction times, growth coefficients, nucleation rate densities,…). By performing further analysis according to classical theory can show that is favored by vanishing barrier height leading conclusion...
The nonalternant aromatic hydrocarbon azulene bonds much more strongly to copper than its alternant isomer naphthalene, illustrating the critical role of molecular topology in controlling metal-organic interfaces electronic devices.
Hybridization-related modifications of the first metal layer a metal-organic interface are difficult to access experimentally and have been largely neglected so far. Here, we study influence specific chemical bonds (as formed by organic molecules CuPc PTCDA) on Pb-Ag surface alloy. We find that delocalized van der Waals or weak $\ensuremath{\pi}$-type not strong enough alter alloy, while localized $\ensuremath{\sigma}$-type lead vertical displacement Pb atoms changes in alloy's band...
The current study generates profound atomistic insights into doping-induced changes of the optical and electronic properties prototypical PTCDA/Ag(111) interface. For doping K atoms are used, as KxPTCDA/Ag(111) has distinct advantage forming well-defined stoichiometric phases. To arrive at a conclusive, unambiguous, fully understanding interface properties, we combine state-of-the-art density-functional theory calculations with differential reflectance data, photoelectron spectra, X-ray...
Interfaces between polycyclic π-electron systems and metals play prominent roles in organic or graphene-based (opto)electronic devices, which performance-related parameters depend critically on the properties of metal/semiconductor contacts. Here, we explore how topology system influences bonding electronic interface. We use azulene as a model for nonalternant pentagon–heptagon (5–7) ring pairs compare it to its isomer naphthalene, represents alternant 6–6 pair. Their coverage-dependent...
We investigated the process of vitrification and crystallization in a model system colloidal hard spheres. The kinetics solidification was measured using time resolved static light scattering, while evolution dynamic properties determined scattering. By performing further analysis we confirm that sphere colloids is mediated by precursors. Analyzing can show long dynamics thus shear rigidity metastable melt highly correlated with number density solid clusters (precursors) nucleated. In these...
We introduce a software, Torricelli, for the analysis of normal incidence x-ray standing wave data. In particular, given experimental reflectivity and photoelectron yield data set (photon energy scan), Torricelli provides corresponding structural parameters. The algorithm equations on which is based are explained here in detail. model takes into account theoretical double crystal monochromator as well sample crystal, Gaussian broadening to mosaicity photon spread. If statistical errors...
Abstract Hexagonal boron nitride, often entitled the ‘white graphene’ because of its large band gap, is one most important two-dimensional (2D) materials and frequently investigated in context with stacked arrays single 2D layers, so called van der Waals heterostructures. Here, we concentrate on growth hBN coinage metal surface Cu(1 1 1). Using low energy electron microscopy diffraction, investigate self-terminated first layer situ real time. Most prominently, find dendritic structures three...
We report the use of a surfactant molecule during epitaxy graphene on SiC(0001) that leads to growth in an unconventional orientation, namely $R0^\circ$ rotation with respect SiC lattice. It yields very high-quality single-layer uniform orientation substrate, wafer scale. find increased quality and homogeneity compared approach based pre-oriented template induce orientation. Using spot profile analysis low energy electron diffraction, angle-resolved photoelectron spectroscopy, normal...
Hard sphere suspensions are well recognized model systems of statistical physics and soft condensed matter. We here investigate the temporal evolution immediate environment nucleating growing crystals and/or their global scale distribution using time resolved Small Angle Light Scattering (SALS). Simultaneously performed Bragg scattering measurements provide an accurate gauging sequence events. apply this approach to studies re-crystallization in several different shear molten hard attractive...
The understanding of the fundamental geometric and electronic properties metal-organic hybrid interfaces is a key issue on way to improving performance organic spintronic devices. Here, we studied adsorption heights copper-II-phthalocyanine (CuPc) 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) ${\mathrm{Pb}}_{1}{\mathrm{Ag}}_{2}$ surface alloy Ag(111) using normal-incidence x-ray standing waves technique. We find significantly larger height both molecules Pb-Ag compared bare which...
Molecular monolayer films containing two different types of molecules (so-called heteromolecular films) are promising candidates for the controlled functionalization metal–organic hybrid interfaces. This is particularly true blends formed by charge donor and acceptor molecules. Here we study systems 3,4,9,10-perylene-tetra-carboxylic-dianhydride (PTCDA) as acceptor, either copper(II) or tin(II) phthalocyanine (CuPc SnPc) donor, adsorbed on Ag(111). We find that both exhibit structural phases...
A suspension of charged colloidal silica spheres exhibiting a bi-modal size distribution particles, thereby mimicking binary mixture, was studied using time-resolved ultra-small-angle synchrotron X-ray scattering (USAXS). The sample, consisting particles diameters d(A) = (104.7 ± 9.0) nm and d(B) (88.1 7.8) (d(A)/d(B) ≈ 1.2), with an estimated composition A(0.6(1))B(0.4(1)), respect to its phase behaviour in dependance particle number density interaction, which the latter modulated by...
One of the most important functionalities atomically thin insulator hexagonal boron nitride (hBN) is its ability to chemically and electronically decouple functional materials from highly reactive surfaces. It therefore utmost importance uncover structural properties on surfaces an atomic mesoscopic length scale. In this paper, we quantify relative coverages structurally different domains a hBN layer Ni(111) surface using low-energy electron microscopy normal incidence x-ray standing wave...