A5042044906- Graphene research and applications
- 2D Materials and Applications
- Topological Materials and Phenomena
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Molecular Junctions and Nanostructures
- Surface and Thin Film Phenomena
- Semiconductor materials and devices
- Quantum and electron transport phenomena
- Nanowire Synthesis and Applications
- Quantum many-body systems
- Phase-change materials and chalcogenides
- Advanced Thermoelectric Materials and Devices
- Thermal properties of materials
- Advanced Materials Characterization Techniques
- Magnetic properties of thin films
- MXene and MAX Phase Materials
- Electronic and Structural Properties of Oxides
Folkwang University of the Arts
2019-2024
University of Siegen
2019-2024
Universidade Federal de Minas Gerais
2016-2022
This article shows that the spin-to-charge current conversion in single-layer graphene (SLG) by means of inverse Rashba-Edelstein effect (IREE) is made possible with integration this remarkable 2D-material unique ferrimagnetic insulator yttrium iron garnet (YIG = $Y_{3}Fe_{5}O_{12}$) as well ferromagnetic metal permalloy (Py $Ni_{81}Sb_{19}$). By X-ray absorption spectroscopy (XAS) and magnetic circular dichroism (XMCD) techniques, we show carbon atoms SLG acquires an induced moment due to...
The electronic topology of ${\mathrm{Bi}}_{4}{\mathrm{Te}}_{3}$, composed alternating ${\mathrm{Bi}}_{2}$ and ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ layers, is investigated by density functional theory angle-resolved photoemission spectroscopy. We find, remarkably, that there are three adjacent strong topological gaps with associated protected surface states within a 2-eV range the Fermi level. existence consecutive Dirac cones in $k$ space gives promise for alternative phenomena applications,...
Abstract We prepare monolayers of tantalum sulfide on Au(111) by evaporation Ta in a reactive background H 2 S. Under sulfur-rich conditions, 2H-TaS develop, whereas under sulfur-poor conditions TaS forms, structure that can be derived from removal the bottom S layer. analyze alignment layers with respect to substrate and relation domains herringbone reconstruction using scanning tunneling microscopy. With help density functional theory calculations we determine registry two phases...
The goal of this work is to study transformations that occur upon heating Bi2Se3 temperatures up 623 K. X-ray diffraction (XRD) and scanning tunneling microscopy (STM) spectroscopy (STS) techniques were used in our investigation. XRD was measured following the 00L 01L truncation rods. These measurements revealed there a coexistence major phase other ones present structures quintuple-layers intercalated with Bismuth bilayers. STM surface material showed presence large hexagonal BixSey domains...
We report on the successful synthesis of a crystal strong topological insulator Bi4Te3 and study its surface electronic response. A combination theoretical experimental techniques allowed for systematic composition properties sample. These include density functional theory (DFT), scanning tunneling microscopy spectroscopy (STM-STS). DFT predicts that distinct states exist two terminations Bi4Te3, i.e. Bi2 Bi2Te3. are also clearly distinguished in STS measurements, which allow choosing main...
Nanoscale heterostructure engineering is the main target for development of optoelectronic devices. In this sense, a precise knowledge local electronic response after materials processing required to envisage technological applications. A number probe techniques that address single nanostructure signals were satisfactorily employed in semiconductor epitaxial systems. work we show use chemically etched nanomembranes allows carrying out scanning tunneling spectroscopy (STS) measurements...
It is known that Sb2Se3 does not exhibit topological insulator behavior due to its orthorhombic structure. The introduction of a small amount bismuth and tellurium may change structure hexagonal, leading stable compound. We report here the synthesis structural, chemical, electronic properties BiSbSe2.5Te0.5. Combining X-ray electron diffraction measurements, we demonstrate formation this quaternary hexagonal single crystal. used photoelectron spectroscopy determine quantitatively exact...
We have used atomically-resolved scanning tunneling microscopy and spectroscopy to study the interplay between atomic electronic structure of graphene formed on copper <italic>via</italic> chemical vapor deposition.
Abstract Epitaxial growth is a versatile method to prepare two-dimensional van der Waals ferroelectrics like group IV monochalcogenides which have potential for novel electronic devices and sensors. We systematically study SnSe monolayer islands grown by molecular beam epitaxy, especially the effect of annealing temperature on shape morphology edges. Characterization samples scanning tunneling microscopy reveals that changes from fractal-dendritic after deposition at room compact rhombic...
Abstract We prepared two-dimensional concentric lateral heterostructures of the monolayer transition metal dichalcogenides MoS 2 and TaS by reactive molecular beam epitaxy on chemically inert weakly interacting Au(111). The are in a size regime where quantum confinement can be expected. Despite large lattice mismatch seamless interconnection two materials has been achieved, confirming that semiconducting core is fully enclosed metallic border around its circumference. resulting strain...
We study the nucleation stage in epitaxial growth of monolayer TaS2 as a model system for transition-metal sulfides. The was done under ultrahigh-vacuum conditions with Au(111) substrate on which metal atoms are evaporated, and sulfur is provided from background H2S. Using scanning tunneling microscopy, we find atomic-scale protrusions well-defined triangular shape that act nuclei further extended tantalum sulfide monolayers. identify these TaS3 using density functional theory. propose their...
The most relevant characteristic of a topological insulator material is the presence edge/surface states that are protected by bulk topology, and therefore, insensitive to nonmagnetic disorder. However, if such disorder induced magnetic atoms or subjected an external field, time-reversal symmetry expected break down, affecting robustness states. In this work, europium (Eu)-doped bismuth telluride thin films were grown molecular beam epitaxy in order analyze effect small fraction with...
We prepare monolayers of tantalum sulfide on Au(111) by evaporation Ta in a reactive background H$_2$S. Under sulfur-rich conditions, 2H-TaS$_2$ develop, whereas under sulfur-poor conditions TaS forms, structure that can be derived from removal the bottom S layer. analyse alignment layers with respect to substrate and relation domains herringbone reconstruction using scanning tunneling microscopy (STM). With help density functional theory (DFT) calculations we determine registry two phases...
In this work, we have investigated the structural and electronic properties of Mg-doped GaAs(111) nanowires synthesized through a vapor–liquid–solid growth mechanism. The crystalline structure these was measured using synchrotron X-ray diffraction, while their addressed by scanning tunneling spectroscopy. Scanning microscopy measurements revealed that conducting Ga2Mg/Mg clusters are observed at {110} nanowire lateral surfaces, allowing electrical contacts with reduced Schottky barriers....
It is well known that tin monosulfide a potential environment-friendly solar cell material maximizes light-energy conversion efficiency, given its band gap at the peak of emission spectrum. However, presence Sn and S vacancies surface SnS hinders performance these cells. In present work, we have prepared sulfide platelets on graphite using vapor phase deposition under temperature gradient. Remarkably, observe two types growth modes: (i) dominant one with platelet-like flat crystals (ii) less...