Publications by Klaus Kern | EPFL Graph Search

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We report on a multi-technique investigation of the supramolecular organisation of N,N-diphenyl oxalic amide under differently dimensioned environments, namely three-dimensional (3D) in the bulk crystal, and in two dimensions on the Ag(111) surface as well ...

We have used variable-temperature scanning tunneling microscopy to study the aggregation of two-dimensional Ag clusters on Pt(111). A transition from randomly ramified to dendritic fractal growth is observed in the diffusion-limited regime. Atomic-scale observations have identified the anisotropy of edge diffusion as microscopic origin of this crossover. Dependent on the deposition flux, this anisotropy is either amplified to the macroscopic-cluster shape and trigonal dendrites result, or it is degenerated

The influence of strain on diffusion and nucleation has been studied by means of scanning tunneling microscopy and effective-medium theory for Ag self-diffusion on strained and unstrained (111) surfaces. Experimentally, the diffusion barrier is observed to be substantially lower on a pseudomorphic Ag monolayer on Pt(111), 60 meV, compared to that on Ag(111), 97 meV. The calculations show that this strong effect is due to the 4.2% compressive strain of the Ag monolayer on Pt. It is shown that in general isot

We derive an analytical expression for the size distribution of monoatomic wires in the framework of a one-dimensional lattice gas model at thermodynamic equilibrium. The theoretical results are compared with the size distribution of one-dimensional Ag wir ...

Experimental control of local spin-charge interconversion is of primary interest for spintronics. Van der Waals (vdW) heterostructures combining graphene with a strongly spin-orbit coupled two-dimensional (2D) material enable such functionality by design. ...

We present a novel method for the fabrication of well-ordered, two-dimensional nanocluster arrays. The method is based on the confined nucleation of adatoms within the superstructure cells of periodic surface dislocation networks, which form in many heteroepitaxial systems. Sire show how quantitative understanding of adatom diffusion and heterogeneous nucleation on such surfaces can be obtained through kinetic Monte-Carlo simulations and discuss the potential of this approach.

We have performed a detailed study of the intrinsic electrical conduction process in individual monolayers of chemically reduced graphene oxide down to a temperature of 2 K. The observed conductance can be consistently interpreted in the framework of two-d ...

Metal-organic coordination interactions are prime candidates for the formation of self-assembled, nanometer-scale periodic networks with room-temperature structural stability. We present X-ray photoelectron spectroscopy measurements of such networks at the ...

Charge recombination dynamics in semiconductor nanostructures is of vital importance for photovoltaic or photodetector device applications. We use local photocurrent measurements to explore spatially separated drift- and diffusion-currents close to the edg ...

Nanostructures are promising candidates for use as active materials for the detection of chemical and biological species, mainly due to the high surface-to-volume ratio and the unique physical properties arising at the nanoscale. Among the various nanostru ...

Variable-temperature scanning tunneling microscopy was used to study the effect of kinetic cluster energy and rare-gas buffer layers on the deposition process of size-selected silver nanoclusters on a platinum(111) surface. Clusters with impact energies of ...

Flexible transistors and circuits based on dinaphtho-[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT), a conjugated semiconductor with a large ionization potential (5.4 eV), are reported. The transistors have a mobility of 0.6 cm(2) V-1 s(-1) and the ring osci ...

The Josephson effect in scanning tunneling microscopy (STM) is an excellent tool to probe the properties of a superconductor on a local scale. We use atomic manipulation in a low temperature STM to create mesoscopic single channel contacts and study the Jo ...

Stacked-graphene carbon nanotubes (SG-CNTs) obtained via pyrolysis of columnar superstructures of polycyclic aromatic hydrocarbons are studied by electrical transport measurements and scanning photocurrent microscopy. The charge transport in individual SG- ...

Apertureless scanning near-field optical microscopy offers superb spatial resolution, but interpreting the recoreded signal can still be a challenge. Especially images of eigenmodes in plasmonic nanostructures are very often obscured by concurrent scatteri ...

Scanning capacitance microscopy and electrostatic force microscopy have been used to characterize commercial semiconductor devices at various stages of the fabrication process. These methods, combined with conventional atomic force microscopy, allow to visualize qualitatively the oxide thickness, the nature of dopants and the exact position of implanted areas. (C) 2002 Elsevier Science Ltd. All rights reserved.

Characterizing the complex structure of such molecules with highly resolving, vacuum-based methods like scanning probe microscopy requires their transfer into the gas phase and further onto an atomically clean surface in ultrahigh vacuum without causing ad ...

We developed a setup that provides three independent optical access paths to the tunnel junction of an ultrahigh vacuum low temperature (4.2 K) scanning tunneling microscope (STM). Each path can be individually chosen to couple light in or out, or to image ...

An optical read-out technique is demonstrated that enables mapping the time-dependent electrostatic potential in the tunnel junction of a scanning tunneling microscope with millivolt and nanosecond accuracy. We measure the time-dependent intensity of plasm ...

Klaus Kern

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Does the Surface Matter? Hydrogen-Bonded Chain Formation of an Oxalic Amide Derivative in a Two- and Three-Dimensional Environment

Aggregation of Fractal and Dendritic Ag Clusters on a Pt(111) Surface

Effect of Strain on Surface-Diffusion and Nucleation

Equilibrium island-size distribution in one dimension

Berry curvature-induced local spin polarisation in gated graphene/WTe2 heterostructures

Self-organized growth of cluster arrays

Electrical Conduction Mechanism in Chemically Derived Graphene Monolayers

Metal-organic coordination interactions in Fe-Terephthalic acid networks on Cu(100)

Efficient Charge Extraction out of Nanoscale Schottky Contacts to CdS Nanowires

25th Anniversary Article: Label-Free Electrical Biodetection Using Carbon Nanostructures

Controlled deposition of size-selected silver nanoclusters

Flexible Low-Voltage Organic Transistors and Circuits Based on a High-Mobility Organic Semiconductor with Good Air Stability

Single channel Josephson effect in a high transmission atomic contact

Electrical Properties and Photoconductivity of Stacked-Graphene Carbon Nanotubes

Plasmonic nanostructures in aperture-less scanning near-field optical microscopy (aSNOM)

A Graphene Nanoribbon Memory Cell

Use of scanning capacitance microscopy for controlling wafer processing

Soft-landing electrospray ion beam deposition of sensitive oligoynes on surfaces in vacuum

Versatile optical access to the tunnel gap in a low-temperature scanning tunneling microscope

Quantitative mapping of fast voltage pulses in tunnel junctions by plasmonic luminescence