Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Sorting out the nanotubes, for better electronics

Francois Gygi and Giulia Galli / UC-Davis
A computer-generated cross section of the polymer-coated carbon nanotube. The polymer shell (blue) wraps around a semiconducting single-walled carbon nanotube (red).
Francois Gygi and Giulia Galli / UC-Davis

A computer-generated cross section of the polymer-coated carbon nanotube. The polymer shell (blue) wraps around a semiconducting single-walled carbon nanotube (red).

Abstract:
A new technique developed by Stanford researchers advances commercial potential of semiconducting carbon nanotubes for printable circuits, bendable display screens, stretchable electronics and solar technology.

Sorting out the nanotubes, for better electronics

Stanford, CA | Posted on November 18th, 2011

BY SARAH JANE KELLER

Carbon nanotubes could make many electronic devices cheaper and more efficient. But when nanotubes are manufactured, tubes that work for solar cells are mixed with tubes that work for batteries. The final product is a nanotube powder that is not ideal for any single commercial application.

Zhenan Bao, Stanford associate professor of chemical engineering, and her colleagues at University of California-Davis and the Samsung Advanced Institute of Technology have discovered a technique to selectively sort semiconducting single-walled carbon nanotubes from the mixture. The results appear online in Nature Communications.

The semiconducting nanotubes could be used in flexible transistors for other technologies that Bao's group develops, including circuits printed on plastic, bendable display screens and stretchable electronics. The nanotubes could also close gaps in solar cell technology.

"Sorting has been a major bottleneck for carbon nanotubes to be viable for practical electronics applications," Bao said. "This work solves the problem of separating the conducting from the semiconducting nanotubes."

Conducting tubes are used in wires and electrodes but semiconducting tubes are the active material for transistors or solar cells. Mixtures of conducting and semiconducting tubes do not carry enough current for wires or battery electrodes. And when the mixture is used for semiconducting, as in a transistor, the excess current from the conducting nanotubes will short the device.

Bao's group uses a polymer that selectively sorts the mixture by wrapping around semiconducting nanotubes, and not conducting nanotubes. Mixing the polymer with commercially available carbon nanotubes in a solvent separates semiconducting tubes from conducting tubes.

In her past work with the polymer, Bao was the first to find that it has good semiconducting properties in transistors. It is now the most widely studied polymer for plastic circuits and plastic transistors and also for plastic solar cells. Bao's group is the first to combine it with semiconducting carbon nanotubes.

This is not the first time a polymer has been used to sort conducting and semiconducting nanotubes. However, past polymers have insulated the nanotubes and required extensive removal treatments to restore the conductivity of the nanotubes.

The polymer in Bao's process does not need to be removed. The final product is a semiconducting nanotube and polymer ink that can be used to make printable electronics.

"Our simple process allows us to build useful devices very easily," she said.

The group tested nearly 200 individual nanotubes to confirm that the polymer only wraps around semiconducting tubes and not conducting tubes. To explain how the polymer wraps around the carbon nanotube, UC-Davis collaborators Giulia Galli and Francois Gygi modeled the geometry of a semiconducting carbon nanotube and its polymer shell.

According to Galli, the model provides "a theoretical explanation of how this polymer actually interacts with the nanotube." The polymer has a long, rigid backbone, with regular arm-like molecular chains along each side. The side chains fit together like fingers, making a ribbon of polymer that wraps around the semiconducting nanotubes.

Bao's work with nanotubes is part of her long-term collaboration with the Samsung Advanced Institute of Technology. "I'm especially happy that this polymer can now be used to sort nanotubes," Bao said. "It merges two very important materials together and makes a hybrid material that could be very useful for printed and flexible electronics."

Jeffrey B.-H. Tok, senior research engineer; Andrew Spakowitz, assistant professor of chemical engineering; and H.S.Philip Wong, professor of electrical engineering, contributed to the research. Chemical engineering graduate student Hang Woo Lee, materials science and engineering graduate students Steve Park and Huiliang Wang also contributed, as well as Satoshi Morishita of chemical engineering,

Luckshitha S. Liyanage of electrical engineering and Nishant Patil of electrical engineering.

The Samsung Advanced Institute of Technology and the National Science Foundation provided funding for the research.

Sarah Jane Keller is a science-writing intern at the Stanford News Service.

####

For more information, please click here

Contacts:
Zhenan Bao
Department of Chemical Engineering
(650) 723-2419


Dan Stober
Stanford News Service:
(650) 721-6965

Copyright © Stanford University

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

Novel 'converter' heralds breakthrough in ultra-fast data processing at nanoscale: Invention bagged four patents and could potentially make microprocessor chips work 1,000 times faster October 20th, 2017

Strange but true: turning a material upside down can sometimes make it softer October 20th, 2017

Leti Coordinating Project to Develop Innovative Drivetrains for 3rd-generation Electric Vehicles: CEA Techís Contribution Includes Litenís Knowhow in Magnetic Materials and Simulation And Letiís Expertise in Wide-bandgap Semiconductors October 20th, 2017

MIPT scientists revisit optical constants of ultrathin gold films October 20th, 2017

Display technology/LEDs/SS Lighting/OLEDs

The secret to improving liquid crystal's mechanical performance: Better lubricating properties of lamellar liquid crystals could stem from changing the mobility of their structural dislocations by adding nanoparticles October 13th, 2017

Missing atoms in a forgotten crystal bring luminescence October 10th, 2017

The power of perovskite: OIST researchers improve perovskite-based technology in the entire energy cycle, from solar cells harnessing power to LED diodes to light the screens of future electronic devices and other lighting applications August 18th, 2017

Flexible Electronics

Tungsten offers nano-interconnects a path of least resistance: Crystalline tungsten shows insight and promise in addressing the challenges of electrical interconnects that have high resistivity at the nanoscale October 4th, 2017

A flexible new platform for high-performance electronics September 29th, 2017

Silk could improve sensitivity, flexibility of wearable body sensors August 20th, 2017

Chip Technology

Novel 'converter' heralds breakthrough in ultra-fast data processing at nanoscale: Invention bagged four patents and could potentially make microprocessor chips work 1,000 times faster October 20th, 2017

MIPT scientists revisit optical constants of ultrathin gold films October 20th, 2017

Bringing the atomic world into full color: Researchers turn atomic force microscope measurements into color images October 19th, 2017

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Nanotubes/Buckyballs/Fullerenes/Nanorods

Long nanotubes make strong fibers: Rice University researchers advance characterization, purification of nanotube wires and films October 17th, 2017

How to draw electricity from the bloodstream: A one-dimensional fluidic nanogenerator with a high power-conversion efficiency September 11th, 2017

Silk could improve sensitivity, flexibility of wearable body sensors August 20th, 2017

Regulation of two-dimensional nanomaterials: New driving force for lithium-ion batteries July 26th, 2017

Nanoelectronics

Nanometrics Announces Preliminary Results for the Third Quarter of 2017: Quarterly Results Impacted by Delays in Revenue Recognition on Multiple Systems into Japan October 12th, 2017

Seeing the next dimension of computer chips: Researchers image perfectly smooth side-surfaces of 3-D silicon crystals with a scanning tunneling microscope, paving the way for smaller and faster computing devices October 11th, 2017

Columbia engineers invent breakthrough millimeter-wave circulator IC October 6th, 2017

Tungsten offers nano-interconnects a path of least resistance: Crystalline tungsten shows insight and promise in addressing the challenges of electrical interconnects that have high resistivity at the nanoscale October 4th, 2017

Discoveries

Novel 'converter' heralds breakthrough in ultra-fast data processing at nanoscale: Invention bagged four patents and could potentially make microprocessor chips work 1,000 times faster October 20th, 2017

Strange but true: turning a material upside down can sometimes make it softer October 20th, 2017

MIPT scientists revisit optical constants of ultrathin gold films October 20th, 2017

Bringing the atomic world into full color: Researchers turn atomic force microscope measurements into color images October 19th, 2017

Announcements

Novel 'converter' heralds breakthrough in ultra-fast data processing at nanoscale: Invention bagged four patents and could potentially make microprocessor chips work 1,000 times faster October 20th, 2017

Strange but true: turning a material upside down can sometimes make it softer October 20th, 2017

Leti Coordinating Project to Develop Innovative Drivetrains for 3rd-generation Electric Vehicles: CEA Techís Contribution Includes Litenís Knowhow in Magnetic Materials and Simulation And Letiís Expertise in Wide-bandgap Semiconductors October 20th, 2017

MIPT scientists revisit optical constants of ultrathin gold films October 20th, 2017

Energy

New nanomaterial can extract hydrogen fuel from seawater: Hybrid material converts more sunlight and can weather seawater's harsh conditions October 4th, 2017

Researchers set time limit for ultrafast perovskite solar cells September 22nd, 2017

Copper catalyst yields high efficiency CO2-to-fuels conversion: Berkeley Lab scientists discover critical role of nanoparticle transformation September 20th, 2017

Solar-to-fuel system recycles CO2 to make ethanol and ethylene: Berkeley Lab advance is first demonstration of efficient, light-powered production of fuel via artificial photosynthesis September 19th, 2017

Solar/Photovoltaic

New nanomaterial can extract hydrogen fuel from seawater: Hybrid material converts more sunlight and can weather seawater's harsh conditions October 4th, 2017

Researchers set time limit for ultrafast perovskite solar cells September 22nd, 2017

Copper catalyst yields high efficiency CO2-to-fuels conversion: Berkeley Lab scientists discover critical role of nanoparticle transformation September 20th, 2017

Solar-to-fuel system recycles CO2 to make ethanol and ethylene: Berkeley Lab advance is first demonstration of efficient, light-powered production of fuel via artificial photosynthesis September 19th, 2017

Printing/Lithography/Inkjet/Inks/Bio-printing

Graphene based terahertz absorbers: Printable graphene inks enable ultrafast lasers in the terahertz range September 13th, 2017

Researchers printed graphene-like materials with inkjet August 17th, 2017

Simultaneous Design and Nanomanufacturing Speeds Up Fabrication: Method enhances broadband light absorption in solar cells August 5th, 2017

Meniscus-assisted technique produces high efficiency perovskite PV films July 7th, 2017

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