Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

android tablet pc

Home > Press > Nanoscience: Weak force. Strong effect.

The van der Waals force, a weak attractive force, is solely responsible for
binding certain organic molecules to metallic surfaces. In a model for
organic devices, it is this force alone that binds an organic film to a
metallic substrate. This data, recently published in Physical Review
Letters, represents the latest findings from a National Research Network
(NRN) supported by the Austrian Science Fund FWF. These findings mean that
numerous calculation models for the physical interactions between thin films
and their carrier materials will need to be revised.

Nanoscience: Weak force. Strong effect.

Austria | Posted on November 19th, 2007

Although they fulfil complex functions when used, for example, as computer
chips, inorganic semiconductors have a simple construction that greatly
limits their application. The same does not apply to semiconductors made of
organic materials. Because organic molecules are extremely flexible, they
can be used in a whole new range of applications. However, before this
advantage can be exploited to the full, scientists need to have a better
understanding of the far greater complexity of these materials over their
inorganic counterparts.

Organic semiconductors are manufactured by applying thin films of an
electrically conductive organic material to a carrier surface. When carrying
out this process, it is important to understand the interactions that occur
at the interfaces between the carrier material and the organic material. A
team from the "Interface controlled and functionalised organic thin films"
National Research Network (NRN) at the University of Leoben has made an
important contribution to scientific understanding in precisely this field.
Using complex calculations, the team has been able to show that a thin film
of organic thiophene is held on to a copper surface solely by the van der
Waals force. The team calculated that the adsorption energy involved is
-0.50 eV.

The spokesperson for the NRN, Prof. Helmut Sitter from the Institute of
Semiconductor and Solid State Physics at Johannes Kepler University (JKU) in
Linz, explains: "The van der Waals force is a weakly interacting force
between atoms that occurs as a result of asymmetric charge distribution in
atoms. We now know that this exerts a highly significant influence on the
kinds of extremely thin material films used to manufacture organic
semiconductors. Indeed, this force can successfully bind the materials
entirely on its own. However, due to its weakness, several previous methods
used to calculate the interactions between different materials have attached
only minor importance to this force, or have ignored it altogether." This
would also seem to provide some explanation for why the generalized gradient
approximation (GGA) often used in such instances has been unable to
satisfactorily explain the bonding behaviour in thin layers. In fact, these
newly published results could explain the discrepancies that have long been
found between various experimental data and models for calculating the
interaction between thin layers.

The new data adds to our fundamental understanding of the interactions that
take place at interfaces. The influence of the van der Waals force also
indicates that no charge is transferred between the atoms of the organic
materials and their substrates in the calculated system. This finding is of
key significance to the production and functionality of organic

Several articles in the Advanced Materials journal this year demonstrate how
research carried out by members of the NRN maintains a steady focus on
practical applications. As a result of one such article, the Institute of
Experimental Physics at JKU won the official Innovation Prize of the
Province of Upper Austria. It is no surprise that three spin-off companies -
run almost exclusively by graduates from the Institutes involved in the NRN
- have already been established as a direct result of the findings. One of
these companies, Nanoident, was declared "Entrepreneur of the Year 2007" by
Ernst & Young Austria.

Prof. Sitter believes that all of these achievements, together with an
article by the NRN published in SCIENCE in the summer of this year, prove
how this National Research Network has successfully combined fundamental
research, applied research and technology transfer - with the support of the

Due to a server upgrade image and text will not be available online until
Tuesday, 20th November 2007, 09.00 a.m. CET onwards:
Image available on request.

Original publication: Importance of Van Der Waals Interaction for Organic
Molecule-Metal Junctions: Adsorption of Thiophene on Cu(110) as a Prototype,
P. Sony, P. Puschnig, D. Nabok & C. Ambrosch-Draxl. Phys. Rev. Lett. 99,
176401 (2007).


For more information, please click here

Scientific Contact:
Prof. Helmut Sitter
Institut für Halbleiter- und Festkörperphysik
Johannes Kepler Universität Linz
T +43 / 732 / 2468 - 9623

Austrian Science Fund FWF:
Mag. Stefan Bernhardt
Haus der Forschung
Sensengasse 1
1090 Wien
T +43 / 1 / 505 67 40 - 8111

Copy Editing and Distribution:
PR&D - Public Relations for Research & Development
Campus Vienna Biocenter 2
1030 Wien
T +43 / 1 / 505 70 44

Vienna, 19th November 2007

Mag. Michaela Fritsch

PR&D - Public Relations for Research & Development

T +43 1 505 70 44
F +43 1 505 50 83

Campus Vienna Biocenter 2
1030 Wien

Copyright © Johannes Kepler Universität Linz

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Chip Technology

Scientists open door to better solar cells, superconductors and hard-drives: Research enhances understanding of materials interfaces April 14th, 2014

Obducat has launched a new generation of SINDRE® Nano Imprint production system April 11th, 2014

Scientists in Singapore develop novel ultra-fast electrical circuits using light-generated tunneling currents April 10th, 2014

Clean Shot at Manufacturing Course…For Less April 9th, 2014


Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

Scientists observe quantum superconductor-metal transition and superconducting glass: A team including MIPT physicist observed quantum superconductor-metal transition and superconducting glass April 16th, 2014

UT Arlington physicist creates new nanoparticle for cancer therapy April 16th, 2014

Targeting cancer with a triple threat: MIT chemists design nanoparticles that can deliver three cancer drugs at a time April 15th, 2014


UT Arlington physicist creates new nanoparticle for cancer therapy April 16th, 2014

Relieving electric vehicle range anxiety with improved batteries: Lithium-sulfur batteries last longer with nanomaterial-packed cathode April 16th, 2014

Aerotech X-Y ball-screw stage for economical high performance Planar positioning April 16th, 2014

Energy Research Facility Construction Project at Brookhaven Lab Wins U.S. Energy Secretary's Achievement Award April 16th, 2014


Energy Research Facility Construction Project at Brookhaven Lab Wins U.S. Energy Secretary's Achievement Award April 16th, 2014

IDTechEx Printed Electronics Europe 2014 Award Winners April 1st, 2014

Dais Analytic Wins SBIR Grant: Dais Analytic Receives US Army Small Business Innovation Research Grant to Further Its Demonstrated Successes in Cleaning Most Forms of Wastewater March 28th, 2014

Scientists develop world’s first light-activated antimicrobial surface that also works in the dark March 24th, 2014


Targeting cancer with a triple threat: MIT chemists design nanoparticles that can deliver three cancer drugs at a time April 15th, 2014

Biologists Develop Nanosensors to Visualize Movements and Distribution of Plant Stress Hormone April 15th, 2014

In latest generation of tiny biosensors, size isn't everything: UCLA researchers overturn conventional wisdom on nanowire-based diagnostic devices April 11th, 2014

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

The latest news from around the world, FREE

  Premium Products
Only the news you want to read!
 Learn More
University Technology Transfer & Patents
 Learn More
Full-service, expert consulting
 Learn More

Nanotechnology Now Featured Books


The Hunger Project

© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE