Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Organic electronics a two-way street, thanks to new plastic semiconductor

19.08.2009
Plastic that conducts electricity holds promise for cheaper, thinner and more flexible electronics.
This technology is already available in some gadgets -- the new Sony walkman that was introduced earlier this summer and the Microsoft Zune HD music player released last week both incorporate organic light-emitting electronic displays.

Until now, however, circuits built with organic materials have allowed only one type of charge to move through them. New research from the University of Washington makes charges flow both ways. The cover article in an upcoming issue of the journal Advanced Materials describes an approach to organic electronics that allows transport of both positive and negative charges.

"The organic semiconductors developed over the past 20 years have one important drawback. It's very difficult to get electrons to move through," said lead author Samson Jenekhe, a UW professor of chemical engineering. "By now having polymer semiconductors that can transmit both positive and negative charges, it broadens the available approaches. This would certainly change the way we do things."

Co-authors are Felix Kim, a doctoral student working with Jenekhe, and graduate student Xugang Guo and assistant professor Mark Watson at the University of Kentucky. The research was funded by the National Science Foundation, the Department of Energy and the Ford Foundation.

Silicon Valley got its name for a reason: Silicon is the "workhorse" of today's electronics industry, Jenekhe said. Silicon is fairly expensive and requires costly manufacturing, however, and because its rigid crystal form does not allow flexible devices.

About 30 years ago it was discovered that some plastics, or polymers, can conduct electricity. Since then researchers have been working to make them more efficient. Organic, or carbon-based, electronics are now used in such things as laptop computers, car audio systems and mp3 players.

A major drawback with existing organic semiconductors is most transmit only positive charges (called "holes" because the moving areas of positive charge are actually places where an electron is missing). In the last decade a few organic materials have been developed that can transport only electrons. But making a working organic circuit has meant carefully layering two complicated patterns on top of one another, one that transports electrons and another one that transports holes.

"Because current organic semiconductors have this limitation, the way they're currently used has to compensate for that, which has led to all kinds of complex processes and complications," Jenekhe said.

For more than a decade Jenekhe's lab has been a leader in developing organic semiconductors that can transmit electrons. Over the past few years the group has created polymers with a donor and an acceptor part, and carefully adjusted the strength of each one. In collaboration with Watson's lab, they have now developed an organic molecule that works to transport both positive and negative charges.

"What we have shown in this paper is that you don't have to use two separate organic semiconductors," Jenekhe said. "You can use one material to create electronic circuits."

The material would allow organic transistors and other information-processing devices to be built more simply, in a way that is more similar to how inorganic circuits are now made.

The group used the new material to build a transistor designed in the same way as a silicon model and the results show that both electrons and holes move through the device quickly.

The results represent the best performance ever seen in a single-component organic polymer semiconductor, Jenekhe said. Electrons moved five to eight times faster through the UW device than in any other such polymer transistor. A circuit, which consists of two or more integrated devices, generated a voltage gain two to five times greater than previously seen in a polymer circuit.

"We expect people to use this approach," Jenekhe said. "We've opened the way for people to know how to do it."

For more information, contact Jenekhe at 206-543-5525 or jenekhe@uw.edu

The paper is available at http://dx.doi.org/10.1002/adma.200901819

Hannah Hickey | EurekAlert!
Further information:
http://www.uw.edu

More articles from Materials Sciences:

nachricht Watching atoms move in hybrid perovskite crystals reveals clues to improving solar cells
22.11.2017 | University of California - San Diego

nachricht Fine felted nanotubes: CAU research team develops new composite material made of carbon nanotubes
22.11.2017 | Christian-Albrechts-Universität zu Kiel

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>