Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Empa researchers clarify reaction pathway to fabricate graphene-like materials

10.11.2010
Graphene is a promising material for tomorrow’s nanoelectronics devices. Precise and upscaleable methods to fabricate graphene and derived materials with desired electronic properties are however still searched after.

To overcome the current limitations, Empa researchers have fabricated graphene-like materials using a surface chemical route and clarified in detail the corresponding reaction pathway. The work has just been published in the scientific journal “Nature Chemistry“. The scientists combined empirical observations using scanning tunnelling microscopy with computer simulations.


The scanning tunnelling microscope images shows nanographene molecules and the two stabilised intermediate products on a copper surface. The molecular models show a nanographene (at the bottom right) as well as the two intermediate products (above and left). In reality the diameter of the molecule is approximately one nanometre. Photo: Empa


Computer-generated image shows details of one of the two intermediate products that the Empa researchers identified with the scanning tunnelling microscope. Photo: Empa

Electronic components are getting smaller and smaller, with microelectronic components gradually being replaced by nanoelectronic ones. On nanoscale dimensions, silicon, which is at the present stage the most commonly used material in semiconductor technology, reaches however a limit, preventing further miniaturization and technological progress. New electronic materials are therefore in great demand. Due to its outstanding electronic properties, graphene, a two-dimensional carbon network, is considered as a possible replacement. However, several obstacles must be overcome before graphene can be used in semiconductor technology. For instance, currently there is no easily applicable method for large-scale processing of graphene-like materials.

Empa researchers of the nanotech@surfaces Laboratory reported on a surface chemical route to fabricate small fragments of graphene, so-called nanographenes. Using a prototypical polyphenylene precursor, the researchers clarified, together with scientists at the Max Planck Institute for Polymer Research in Mainz (Germany) and the University of Zurich, how the reaction pathway runs in detail on a copper surface und how the building blocks can be transformed into planar nanographenes directly on the surface. The work has been published last Sunday in the scientific journal “Nature Chemistry” as an advanced online publication.

Successful partners: experiment and simulation

For their investigations the researchers combined empirical observations, in particular from scanning tunnelling microscopy with computer simulations. The simulations are used to determine whether a theoretically possible reaction step is energetically possible or not. The result: the reaction pathway consists of six steps with five intermediate products. Two of them are stabilised by the surface so that they can be stably imaged with the scanning tunnelling microscope. The reaction barriers connecting the different intermediates are lowered through a catalytic effect of the substrate.

To be capable of being integrated in electronic circuits, the graphene-like material must however be manufactured on semiconductor surfaces instead of metal ones. The researchers have simulated whether their approach could also work on these surfaces and the results are very promising, showing that surface-supported synthesis is a possible way to fabricate tailored nanographenes on a range of different substrates.

The three pillars of today’s science: theory, experiment, and simulation

Progress in today’s scientific research relies at the same time on theory, experiments, and to an increasing extent on computer simulations. These simulations are complementary to often complex lab experiments and make it possible to get further information that cannot be obtained with experimental methods alone. The combination of experiments and simulations as well as the deduced theories therefore allow for a more and more accurate explanation and precise prediction of natural phenomena.

Literature reference
“Surface-assisted cyclodehydrogenation provides a synthetic route towards easily processable and chemically tailored nanographenes”, M. Treier, C.A. Pignedoli, T. Laino, R. Rieger, K. Müllen, D. Passerone, R. Fasel, Nature Chemistry, published online 7 November 2010; DOI: 10.1038/NCHEM.891

Beatrice Huber | idw
Further information:
http://www.empa.ch

More articles from Materials Sciences:

nachricht New design improves performance of flexible wearable electronics
23.06.2017 | North Carolina State University

nachricht Plant inspiration could lead to flexible electronics
22.06.2017 | American Chemical Society

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>