Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Polymers can be semimetals

09.12.2013
Polymers can behave like insulators, semiconductors and metals – as well as semimetals. Twenty researchers, under the leadership of Xavier Crispin, Docent in organic electronics at Linköping University, are behind the breakthrough published in Nature Materials.

Traditional plastics, or polymers, are electrical insulators. In the seventies a new class of polymers that conduct electricity like semiconductors and metals was discovered by Alan J.Heeger, Alan G. MacDiarmid and Hideki Shirakawa.


Photo: Ida Ling Flanagan

This was the motivation for their Nobel Prize in Chemistry year 2000. Now Xavier Crispin, Docent in organic electronics at Linköping University’s Department of Science and Technology, has led a project where no fewer than twenty researchers from five universities worldwide have collaborated to prove that polymers can also be semimetals.

The results are published in an article in the prestigious journal Nature Materials, with Dr Crispin as principal author.

A few years ago Xavier Crispin discovered that conductive polymers can be thermoelectric. A thermoelectric material undergoes a diffusion of electronic charge carriers to the cold region when the material is submitted to a temperature gradient. As a result an electric potential is created between the cold and hot side of the material. This thermo-voltage is the basis of thermo-couples used for instance in an everyday oven thermometer.

Xavier Crispin“Our experiments yielded a high thermoelectric effect, a Seebeck effect, which indicated that we were dealing with semimetals. But we needed proof,” says Dr Crispin.

This required talented people from various locations to gain an in-depth understanding of the phenomenon.

No less than twenty researchers from Sweden, Australia, Belgium, Norway and Denmark are co-authors of the article in Nature Materials. Ten of them are from Linköping University, including Xavier Crispin, Professor Magnus Berggren and Igor Zozoulenko from the Laboratory of Organic Electronics, Department of Science and Technology, Campus Norrköping, as well as Professor Mats Fahlman, Division of Surface Physics and Chemistry, and Professor Weimin Chen, Division of Functional Electronic Materials, both at the Department of Physics, Chemistry and Biology.

“It has been very impressive to see how Xavier Crispin has led this. We have a fantastic environment for materials research at Linköping University, with world-leading expertise. We are all friends and we’ve been able to produce this article without joint funding,” says Magnus Berggren, professor or organic electronics.

The theoretical input of Igor Zozoulenko, advanced spectroscopic analysis by Mats Fahlman and Weimin Chen at Linköping University, as well as state-of-the-art polymer samples and morphology studies by research colleagues in Australia, Belgium, Norway and Denmark showed the exact same thing: the polymer, in this case a doped variant of the plastic PEDOT, behaves exactly like a semimetal, which also explains the high Seebeck effect.

Thermoelectric generators are available on the market today, but these are made from alloys of bismuth and the semimetal tellurium. Unlike the polymers, these elements are both rare and expensive.

“These polymers are both easy and inexpensive to produce. That we now have an understanding of these phenomena will really drive developments forward, and will open up a new research field in organic electronics,” says Prof Berggren.

The research was financed primarily by ERC, the European Research Council. In 2012 Dr Crispin was awarded an ERC Starting Grant of SEK 13 million.

Photo: Ida Ling Flanagan

Related links

Laboratory of Organic Electronics, ITN
http://fe.itn.liu.se/orgel/?l=en&sc=true
Semi-metallic polymers, Nature Materials
http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat3824.html
Olga Bubnova, Zia Ullah Khan, HuiWang, Igor Zozoulenko, Magnus Berggren and Xavier Crispin, Department of Science and Technology, Linköping University, Sweden.

Slawomir Braun, Daniel Dagnelund, Weimin M. Chen and Mats Fahlman, Department of Physics, Chemistry and Biology, Linköping University, Sweden.

Drew R. Evans, Manrico Fabretto, Pejman Hojati-Talemi, Peter J. Murphy, University of South Australia, Mawson Lakes, Australia.

Jean-Baptiste Arlin, Yves Geerts, Free University of Brussels, Bryssel, Belgium.

Simon Desbief, Roberto Lazzaroni, University of Mons, Mons, Belgium.

Dag W Breiby, Norwegian University of Science and Technology, Trondheim, Norway.

Jens W Andreasen, Technical University of Denmark, Roskilde, Denmark.

Nature Materials 2013-12-08
www.nature.com/naturematerials

Xavier Crispin | EurekAlert!
Further information:
http://www.liu.se
http://www.nature.com/naturematerials
http://www.liu.se/forskning/forskningsnyheter/1.530026?l=en&sc=true

More articles from Materials Sciences:

nachricht New biomaterial could replace plastic laminates, greatly reduce pollution
21.09.2017 | Penn State

nachricht Stopping problem ice -- by cracking it
21.09.2017 | Norwegian University of Science and Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>