U. Höfer
YOU?
Author Swipe
View article: Second Harmonic Characteristics of Large‐Area ALD‐Grown MoS <sub>2</sub> Monolayers and MoS <sub>2</sub> /WS <sub>2</sub> Heterostructures with Sub‐Millimeter Crystalline Orientation
Second Harmonic Characteristics of Large‐Area ALD‐Grown MoS <sub>2</sub> Monolayers and MoS <sub>2</sub> /WS <sub>2</sub> Heterostructures with Sub‐Millimeter Crystalline Orientation Open
The crystal orientation uniformity of MoS 2 monolayers grown by atomic layer deposition (ALD) on sapphire substrates is investigated, and their integration with spin‐coated WS 2 in a MoS 2 /WS 2 heterostructure. Polarization‐resolved secon…
View article: Design and Engineering of Semiconductor–Organic Interfaces: Multilayer Synthesis on the Si(001) Surface Based on Cyclooctyne Chemistry
Design and Engineering of Semiconductor–Organic Interfaces: Multilayer Synthesis on the Si(001) Surface Based on Cyclooctyne Chemistry Open
ConspectusIn this Account, we will focus on how chemoselective strategies were employed for the controlled synthesis of organic multilayers on silicon, thus forming well-defined semiconductor-organic interfaces. We will start with the chem…
View article: Interface‐Specific Excitation of Coherent Phonons at the Buried GaP/Si(001) Heterointerface
Interface‐Specific Excitation of Coherent Phonons at the Buried GaP/Si(001) Heterointerface Open
Ultrafast charge‐carrier and phonon dynamics at the buried heterointerface of GaP/Si(001) are investigated by means of two‐color pump‐probe reflectivity measurements. The carrier‐induced reflectivity signal exhibits a resonant enhancement …
View article: Time-resolved photoelectron spectroscopy at surfaces
Time-resolved photoelectron spectroscopy at surfaces Open
http://dx.doi.org/10.13039/501100002347 Bundesministerium für Bildung und Forschung
View article: Coherent and Incoherent Excitation Pathways in Time-Resolved Photoemission Orbital Tomography of CuPc/Cu(001)-2O
Coherent and Incoherent Excitation Pathways in Time-Resolved Photoemission Orbital Tomography of CuPc/Cu(001)-2O Open
Time-resolved photoemission orbital tomography (tr-POT) offers unique possibilities for tracing molecular electron dynamics. The recorded pump-induced changes of the angle-resolved photoemission intensities allow to characterize unoccupied…
View article: Tip-Induced Dissociation of Diethyl Ether on Si(001)─Influence of Molecular Structure on Final Reaction Products
Tip-Induced Dissociation of Diethyl Ether on Si(001)─Influence of Molecular Structure on Final Reaction Products Open
Scanning tunneling microscopy gives access to well-controlled manipulation of surface adsorbates by means of activating reaction pathways beyond thermal excitation schemes. For the conversion of diethyl ether on Si(001) from a datively bou…
View article: Strongly coupled interface electronic states and interface phonon mode at GaP/Si(001)
Strongly coupled interface electronic states and interface phonon mode at GaP/Si(001) Open
Ultrafast carrier and phonon dynamics at the buried heterointerface of GaP/Si(001) are investigated by means of two-color pump-probe reflectivity measurements. The carrier-induced reflectivity signal exhibits a resonant enhancement at pump…
View article: Build-up and dephasing of Floquet–Bloch bands on subcycle timescales
Build-up and dephasing of Floquet–Bloch bands on subcycle timescales Open
View article: Ultrafast electron dynamics in a topological surface state observed in two-dimensional momentum space
Ultrafast electron dynamics in a topological surface state observed in two-dimensional momentum space Open
View article: Terahertz radiation from propagating acoustic phonons based on deformation potential coupling
Terahertz radiation from propagating acoustic phonons based on deformation potential coupling Open
We report on new THz electromagnetic emission mechanism from deformational coupling of acoustic (AC) phonons with electrons in the propagation medium of non-polar Si. The epicenters of the AC phonon pulses are the surface and interface of …
View article: Separation of interface and substrate carrier dynamics at a heterointerface based on coherent phonons
Separation of interface and substrate carrier dynamics at a heterointerface based on coherent phonons Open
Transient reflectivity spectroscopy is widely used to study ultrafast carrier- and phonon-dynamics in semiconductors. In their heterostructures, it is often not straightforward to distinguish contributions to the signal from the various la…
View article: Separation of interface and substrate carrier dynamics at a heterointerface based on coherent optical phonons
Separation of interface and substrate carrier dynamics at a heterointerface based on coherent optical phonons Open
Transient reflectivity spectroscopy is widely used to study ultrafast carrier- and phonon-dynamics in semiconductors. In their heterostructures, it is often not straightforward to distinguish contributions to the signal from the various la…
View article: Ultrafast Charge-Transfer Dynamics in Twisted MoS<sub>2</sub>/WSe<sub>2</sub> Heterostructures
Ultrafast Charge-Transfer Dynamics in Twisted MoS<sub>2</sub>/WSe<sub>2</sub> Heterostructures Open
Two-dimensional transition metal dichalcogenides offer a fascinating platform for creating van der Waals heterojunctions with exciting physical properties. Because of their typical type-II band alignment, photoexcited electrons and holes c…
View article: Momentum-Resolved Observation of Exciton Formation Dynamics in Monolayer WS<sub>2</sub>
Momentum-Resolved Observation of Exciton Formation Dynamics in Monolayer WS<sub>2</sub> Open
The dynamics of momentum-dark exciton formation in transition metal dichalcogenides is difficult to measure experimentally, as many momentum-indirect exciton states are not accessible to optical interband spectroscopy. Here, we combine a t…
View article: Tip-induced β -hydrogen dissociation in an alkyl group bound on Si(001)
Tip-induced β -hydrogen dissociation in an alkyl group bound on Si(001) Open
Atomic-scale chemical modification of surface-adsorbed ethyl groups on Si(001) was induced and studied by means of scanning tunneling microscopy. Tunneling at sample bias >+1.5 V leads to tip-induced C–H cleavage of a β -hydrogen of the co…
View article: Ultrafast charge-transfer dynamics in twisted MoS$_2$/WSe$_2$ heterostructures
Ultrafast charge-transfer dynamics in twisted MoS$_2$/WSe$_2$ heterostructures Open
Two-dimensional transition metal dichalcogenides (TMD) offer a unique platform for creating van-der-Waals heterojunctions with fascinating physical properties and promising applications in optoelectronics and valleytronics. Because of thei…
View article: Tip-Induced $\beta$-Hydrogen Dissociation in an Alkyl Group Bound on Si(001)
Tip-Induced $\beta$-Hydrogen Dissociation in an Alkyl Group Bound on Si(001) Open
Atomic-scale chemical modification of surface-adsorbed ethyl groups on\nSi(001) was induced and studied by means of scanning tunneling microscopy.\nTunneling at sample bias > +1.5V leads to tip-induced C-H cleavage of a\n$\\beta$-hydrogen …
View article: Adsorption dynamics of bifunctional molecules: Allyl methyl ether on Si(001)
Adsorption dynamics of bifunctional molecules: Allyl methyl ether on Si(001) Open
The reaction dynamics of allyl methyl ether (AME) on Si(001) was studied by means of molecular beam techniques. The reaction of this bifunctional molecule comprising an ether and an alkene group was found to proceed via an intermediate sta…
View article: Data archive of 'Tuneable non-integer high-harmonic generation in a topological insulator'
Data archive of 'Tuneable non-integer high-harmonic generation in a topological insulator' Open
View article: Direct observation of ultrafast dark exciton formation in monolayer WS$_2$
Direct observation of ultrafast dark exciton formation in monolayer WS$_2$ Open
The exciton landscape in transition metal dichalcogenides is crucial for their optical properties and difficult to measure experimentally, since many exciton states are not accessible to optical interband spectroscopy. Here, we combine a t…
View article: Ultrafast Dynamics of Photocurrents in Surface States of Three‐Dimensional Topological Insulators
Ultrafast Dynamics of Photocurrents in Surface States of Three‐Dimensional Topological Insulators Open
Herein, experimental work on the ultrafast electron dynamics in the topological surface state (TSS) of three‐dimensional (3D) topological insulators (TIs) observed with time‐ and angle‐resolved two‐photon photoemission (2PPE) is reviewed. …
View article: Impact of interface-state formation on the charge-carrier dynamics at organic-metal interfaces
Impact of interface-state formation on the charge-carrier dynamics at organic-metal interfaces Open
We study the role of electronic interface states on the electron transfer dynamics between layers of the organic semiconductor 3,4,9,10-perylene-tetracarboxylic acid dianhydride (PTCDA) and the (111) and (100) surfaces of silver. For this …
View article: Directional ultrafast charge transfer in a WSe<sub>2</sub>/MoSe<sub>2</sub> heterostructure selectively probed by time-resolved SHG imaging microscopy
Directional ultrafast charge transfer in a WSe<sub>2</sub>/MoSe<sub>2</sub> heterostructure selectively probed by time-resolved SHG imaging microscopy Open
Directional interlayer charge transfer in TMD heterostructure probed by time- and polarization-resolved second-harmonic imaging microscopy.
View article: Magnetic-impurity-induced modifications to ultrafast carrier dynamics in the ferromagnetic topological insulators Sb<sub>2−x</sub>V<sub>x</sub>Te<sub>3</sub>
Magnetic-impurity-induced modifications to ultrafast carrier dynamics in the ferromagnetic topological insulators Sb<sub>2−x</sub>V<sub>x</sub>Te<sub>3</sub> Open
Quantum anomalous Hall effect (QAHE) is a key phenomenon for low power-consumption device applications owing to its dissipationless spin-polarized and quantized current in the absence of an external magnetic field. However, the recorded wo…
View article: Der Naturschutz kann besser werden
Der Naturschutz kann besser werden Open
Die Naturschutzarbeit kann durch eine konsequente Anwendung des Prinzips des evidenzbasierten Naturschutzes verbessert werden. Ziel ist es, aus einer Fulle von Einzelfallen allgemeingultige Erkenntnisse zu gewinnen.
View article: Révolutionner la protection de la nature en l'ancrant dans l'évidence scientifique!
Révolutionner la protection de la nature en l'ancrant dans l'évidence scientifique! Open
View article: Data archive of "Subcycle observation of lightwave-driven Dirac currents in a topological surface band"
Data archive of "Subcycle observation of lightwave-driven Dirac currents in a topological surface band" Open
View article: Electronic Structure of Titanylphthalocyanine Layers on Ag(111)
Electronic Structure of Titanylphthalocyanine Layers on Ag(111) Open
We have investigated the electronic structures of axially oxo functionalized titanylphthalocyanine (TiOPc) on Ag(111) by X-ray and ultraviolet photoelectron spectroscopies, two-photon photoemission, X-ray absorption spectroscopy, and X-ray…
View article: Sub-picosecond acoustic pulses at buried GaP/Si interfaces
Sub-picosecond acoustic pulses at buried GaP/Si interfaces Open
We report on the optical generation and detection of ultrashort acoustic pulses that propagate in three-dimensional semiconductor crystals. Photoexcitation of lattice-matched GaP layers grown on Si(001) gives rise to a sharp spike in trans…
View article: Model potential for the description of metal/organic interface states
Model potential for the description of metal/organic interface states Open