Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Bottoms Up: Better Organic Semiconductors for Printable Electronics

Restacking organic semiconductors: An improved formulation for a polymer blend semiconductor causes key semiconducting molecules to migrate to the bottom of the active layer, allowing chip designers to replace top-gated structures (a) with more easily manufactured bottom-gate, bottom-contact devices (b).

Credit: Yoon, SNU/Talbott, NIST
Restacking organic semiconductors: An improved formulation for a polymer blend semiconductor causes key semiconducting molecules to migrate to the bottom of the active layer, allowing chip designers to replace top-gated structures (a) with more easily manufactured bottom-gate, bottom-contact devices (b).

Credit: Yoon, SNU/Talbott, NIST

Abstract:
Researchers from the National Institute of Standards and Technology (NIST) and Seoul National University (SNU) have learned how to tweak a new class of polymer-based semiconductors to better control the location and alignment of the components of the blend. Their recent results—how to move the top to the bottom—could enable the design of practical, large-scale manufacturing techniques for a wide range of printable, flexible electronic displays and other devices.*

Bottoms Up: Better Organic Semiconductors for Printable Electronics

GAITHERSBURG, MD | Posted on September 3rd, 2008

Organic semiconductors—novel carbon-based molecules that have similar electrical properties to more conventional semiconducting materials like silicon and germanium—are a hot research topic because practical, high-performance organic semiconductors would open up whole new categories of futuristic electronic devices. Think of tabloid-sized "digital paper" that you could fold up into your pocket or huge sheets of photovoltaic cells that are dirt cheap because they're manufactured by—basically—ink-jet printing.

The problem is performance. Small organic molecules have been developed with key electrical parameters close to the benchmark set by amorphous silicon semiconductors, but they are very difficult to deposit in a stable, uniform film—a key manufacturing requirement. Larger molecule polymer semiconductors, on the other hand, make excellent thin films but have at best limited semiconductor properties. A patent from British researchers in 2005 offered a promising compromise: blend the small semiconductor molecules in with the polymer. This works surprisingly well, but with an asterisk. Tests showed that actual devices, field effect transistors, made with the blend only worked well in a so-called "top-gated" structure. The critical active part of the film was on the top, and the switching part of the device (the "gate") had to be layered on top of that, a process difficult or impossible to do on a large scale without destroying the fragile film.

Working at NIST's Center for Neutron Research, the SNU/NIST research team used a neutron imaging technique that allowed them to observe, with nanometer resolution, how the distribution of small organic semiconductor molecules embedded in polymer films changed with depth—the films are less than 100 nanometers thick. In the thin films originally described by the patent, the bulk of the semiconductor molecules end up at the top of the film, as suspected. However, when the SNU/NIST research team substituted a polymer with significantly higher molecular mass, something interesting happened. The organic semiconductor small molecules distributed themselves evenly at the top and bottom of the film. Having an active region of the film on the bottom is key for large-scale manufacturing because it means the rest of the device—gate, source, drain—can be laid down first and the delicate film layer added last.

In addition, they report, the optimized blend of polymer and organic semiconductor actually has better performance characteristics than the organic semiconductor on its own.

* J. Kang, N. Shin, D.Y. Jang, V.M. Prabhu and D.Y. Yoon. Structure and properties of small molecule-polymer blend semiconductors for organic thin film transistors. Journal of the American Chemical Society, Published on the Web Aug. 23, 2008.

####

About NIST
Founded in 1901, NIST is a non-regulatory federal agency within the U.S. Department of Commerce. NIST's mission is to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.

For more information, please click here

Contacts:
Michael Baum

(301) 975-2763

Copyright © NIST

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.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Study reveals how herpes virus tricks the immune system February 5th, 2016

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Organic crystals allow creating flexible electronic devices: The researchers from the Faculty of Physics of the Moscow State University have grown organic crystals that allow creating flexible electronic devices February 5th, 2016

Researchers discover new phase of boron nitride and a new way to create pure c-BN February 5th, 2016

Chip Technology

Organic crystals allow creating flexible electronic devices: The researchers from the Faculty of Physics of the Moscow State University have grown organic crystals that allow creating flexible electronic devices February 5th, 2016

Scientists guide gold nanoparticles to form 'diamond' superlattices: DNA scaffolds cage and coax nanoparticles into position to form crystalline arrangements that mimic the atomic structure of diamond February 4th, 2016

Polar vortices observed in ferroelectric: New state of matter holds promise for ultracompact data storage and processing February 4th, 2016

Electrons and liquid helium advance understanding of zero-resistance: Study of electrons on liquid helium systems sheds light on zero-resistance phenomenon in semiconductors February 2nd, 2016

Discoveries

Study reveals how herpes virus tricks the immune system February 5th, 2016

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Researchers discover new phase of boron nitride and a new way to create pure c-BN February 5th, 2016

Joint Efforts by Iranian, Malaysian Scientists Produce Antibacterial Coatings for Isolated Areas February 4th, 2016

Announcements

Study reveals how herpes virus tricks the immune system February 5th, 2016

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Organic crystals allow creating flexible electronic devices: The researchers from the Faculty of Physics of the Moscow State University have grown organic crystals that allow creating flexible electronic devices February 5th, 2016

Researchers discover new phase of boron nitride and a new way to create pure c-BN February 5th, 2016

Research partnerships

Polar vortices observed in ferroelectric: New state of matter holds promise for ultracompact data storage and processing February 4th, 2016

Spin dynamics in an atomically thin semi-conductor February 1st, 2016

Graphene shown to safely interact with neurons in the brain January 31st, 2016

Are some people more likely to develop adverse reactions to nanoparticle-based medicines? January 31st, 2016

Printing/Lithography/Inkjet/Inks

Teijin to Participate in Nano Tech 2016 January 21st, 2016

New bimetallic alloy nanoparticles for printed electronic circuits: Production of oxidation-resistant copper alloy nanoparticles by electrical explosion of wire for printed electronics January 5th, 2016

Photonic “sintering” may create new solar, electronics manufacturing technologies December 1st, 2015

Screen Printable Functionalised Graphene Ink November 3rd, 2015

NanoNews-Digest
The latest news from around the world, FREE




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











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic