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 linksLaboratory of Organic Electronics, ITN
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
Xavier Crispin | EurekAlert!
Reliable molecular toggle switch developed
30.03.2017 | Karlsruher Institut für Technologie (KIT)
Researchers shoot for success with simulations of laser pulse-material interactions
29.03.2017 | DOE/Oak Ridge National Laboratory
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
30.03.2017 | Health and Medicine
30.03.2017 | Health and Medicine
30.03.2017 | Medical Engineering