A5020109503- Surface and Thin Film Phenomena
- Semiconductor materials and interfaces
- 2D Materials and Applications
- Graphene research and applications
- Topological Materials and Phenomena
- Ga2O3 and related materials
- Advanced Materials Characterization Techniques
- Semiconductor materials and devices
- Molecular Junctions and Nanostructures
- Physics of Superconductivity and Magnetism
- Force Microscopy Techniques and Applications
- Photorefractive and Nonlinear Optics
- Advanced Thermoelectric Materials and Devices
- Optical Coatings and Gratings
- Copper Interconnects and Reliability
- Quantum many-body systems
- Advanced Condensed Matter Physics
- Optical and Acousto-Optic Technologies
- Nonlinear Optical Materials Research
- Perovskite Materials and Applications
- Organic Electronics and Photovoltaics
- Quantum and electron transport phenomena
- Photonic and Optical Devices
University of Giessen
2019-2024
University of Trento
2024
Paderborn University
2014-2016
We report the discovery of a temperature-induced phase transition between α and β structures antimonene. When antimony is deposited at room temperature on bismuth selenide, it forms domains α-antimonene having different orientations with respect to substrate. During mild annealing, grows prevails over phase, eventually forming single domain that perfectly matches surface lattice structure selenide. First-principles thermodynamics calculations this van der Waals heterostructure explain...
One-dimensional wires are known to be inherently unstable at finite temperature. Here, we show that long-range order of atomic Au double chains adsorbed on a Si(553) surface is not only stabilized by interaction with the substrate, but spontaneous self-healing structural defects actually enforced adsorption species such as or H. This true even for random adsorbate distribution. Combining atomistic models within density functional theory low energy electron diffraction and high-resolution...
Abstract Topological surface states usually emerge at the boundary between a topological and conventional insulator. Their precise physical character spatial localization depend on complex interplay chemical, structural electronic properties of two insulators in contact. Using lattice-matched heterointerface single double bilayers β-antimonene bismuth selenide, we perform comprehensive experimental theoretical study chiral by means microscopy spectroscopic measurements complemented...
Ultrathin metallic silicide nanowires with extremely high aspect ratios can be easily grown, e.g., by deposition of rare earth elements on semiconducting surfaces. These wires play a pivotal role in fundamental research and open intriguing perspectives for CMOS applications. However, the electronic properties these one-dimensional systems are sensitive to atomic-sized defects, which alter transport characteristics. In this study, we characterized comprehensively ${\mathrm{TbSi}}_{2}$ grown...
Rare-earth deposition on Si(001) substrates and thermal treatment lead to the formation of metastable silicide nanowires with extremely high aspect ratios quasi-one-dimensional metallicity. In this work, prototypical erbium are investigated theoretically by ab initio thermodynamics, considering a multitude possible nanowire structures. The calculations indicate that consist hexagonal ${\mathrm{ErSi}}_{2}$ two orientations respect substrate, they partially buried into electronically decoupled...
Thin antimony layers adsorbed on bismuth selenide (Bi2Se3) present an exciting topological insulator system. Much recent effort has been made to understand the synthesis and electronic properties of heterostructure, particularly migration surface states under adsorption. However, intertwinement pristine Bi2Se3 substrate with Sb adlayer remains unclear. In this theoretical work, we apply density functional theory (DFT) model heterostructures single double atomic a substrate. We thereby...
We present a theoretical study of the thermodynamical factors that determine epitaxial formation single layer 2D pnictogen (P, As, Sb, Bi) allotropes on substrates any type. The interplay substrate-adlayer interaction and strain induced by matching is analyzed in terms phase diagram describing growth during gaseous deposition stage. necessary conditions to favor particular allotrope (in particular, $\ensuremath{\alpha}$ $\ensuremath{\beta}$ phases) are determined. show buckled Sb Bi layers...
Two-dimensional rare-earth silicide layers deposited on silicon substrates have been intensively investigated in the last decade, as they can be exploited both Ohmic contacts or photodetectors, depending substrate doping. In this study, we characterize Si(111) surface by a spectroscopic analysis. detail, combine Raman and reflectance anisotropy spectroscopy (RAS) with first-principles calculations framework of density functional theory. RAS suggests weakly isotropic surface, reveals presence...
In a joint experimental and theoretical study on metallic $\mathrm{Tb}{\mathrm{Si}}_{2}$ nanowires, we observe continuous crossover from two-dimensional (2D) to quasi-one-dimensional (1D) electronic structure by reduction of the nanowire width. The nanowires were grown self-organization vicinal Si(111) substrates denoted Miller indices $(hhk)$. Their was analyzed angle-resolved photoemission spectroscopy (ARPES) calculated using density functional theory (DFT). ARPES, show basically 2D film...
Light-induced ordered states can emerge in materials after irradiation with ultrafast laser pulses. However, their prediction is challenging because the inverted band occupation confounds our chemical intuition. Hence, we use a recently developed constrained density functional perturbation theory approach to systematically screen single-layer transition metal dichalcogenides (TMDs) for light-induced states. We demonstrate that all examined TMDs reveal similar charge orderings. The...