Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Triple-mode transistors show potential

Top left: A graphene transistor with source and drain electrodes; top right, a schematic for the triple-mode single-transistor graphene amplifier; and bottom, a graph showing the three distinct modes of operation. (Images: Mohanram Lab/Rice University)
Top left: A graphene transistor with source and drain electrodes; top right, a schematic for the triple-mode single-transistor graphene amplifier; and bottom, a graph showing the three distinct modes of operation. (Images: Mohanram Lab/Rice University)

Abstract:
Rice researchers introduce graphene-based amplifiers

Triple-mode transistors show potential

Houston, TX | Posted on October 13th, 2010

Rice University research that capitalizes on the wide-ranging capabilities of graphene could lead to circuit applications that are far more compact and versatile than what is now feasible with silicon-based technologies.

Triple-mode, single-transistor amplifiers based on graphene -- the one-atom-thick form of carbon that recently won its discoverers a Nobel Prize -- could become key components in future electronic circuits. The discovery by Rice researchers was reported this week in the online journal ACS Nano.

Graphene is very strong, nearly transparent and conducts electricity very well. But another key property is ambipolarity, graphene's ability to switch between using positive and negative carriers on the fly depending on the input signal. Traditional silicon transistors usually use one or the other type of carrier, which is determined during fabrication.

A three-terminal single-transistor amplifier made of graphene can be changed during operation to any of three modes at any time using carriers that are positive, negative or both, providing opportunities that are not possible with traditional single-transistor architectures, said Kartik Mohanram, an assistant professor of electrical and computer engineering at Rice. He collaborated on the research with Alexander Balandin, a professor of electrical engineering at the University of California, Riverside, and their students Xuebei Yang (at Rice) and Guanxiong Liu (at Riverside).

Mohanram likened the new transistor's abilities to that of a water tap. "Turn it on and the water flows," he said. "Turn it off and the water stops. That's what a traditional transistor does. It's a unipolar device -- it only opens and closes in one direction."

"But if you close a tap too much, it opens again and water flows. That's what ambipolarity is -- current can flow when you open the transistor in either direction about a point of minimum conduction."

That alone means a graphene transistor can be "n-type" (negative) or "p-type" (positive), depending on whether the carrier originates from the source or drain terminals (which are effectively interchangeable). A third function appears when the input from each carrier is equal: The transistor becomes a frequency multiplier. By combining the three modes, the Rice-Riverside team demonstrated such common signaling schemes as phase and frequency shift keying for wireless and audio applications.

"Our work, and that of others, that focuses on the applications of ambipolarity complements efforts to make a better transistor with graphene," Mohanram said. "It promises more functionality." The research demonstrated that a single graphene transistor could potentially replace many in a typical integrated circuit, he said. Graphene's superior material properties and relative compatibility with silicon-based manufacturing should allow for integration of such circuits in the future, he added.

Technological roadblocks need to be overcome, Mohanram said. Such fabrication steps as dielectric deposition and making contacts "wind up disturbing the lattice, scratching it and introducing defects. That immediately degrades its performance (limiting signal gain), so we have to exercise a lot of care in fabrication.

"But the technology will mature, since so many research groups are working hard to address these challenges," he said.

The National Science Foundation and the DARPA-Semiconductor Research Corporation's Focus Center Research Program supported the work.

Read the abstract at pubs.acs.org/doi/abs/10.1021/nn1021583.

####

For more information, please click here

Contacts:
David Ruth
713-348-6327


Mike Williams
713-348-6728

Copyright © Rice 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

Information storage with a nanoscale twist: Discovery of a novel rotational force inside magnetic vortices makes it easier to design ultrahigh capacity disk drives March 28th, 2017

ATTOPSEMI Technology Joins FDXcelerator Program to Deliver Advanced Non-Volatile Memory IP to GLOBALFOUNDRIES 22 FDX Technology Platform: Leading-edge I-fuse brings higher reliability, smaller cell size and ease of programmability for consumer, automotive, and IoT applications March 27th, 2017

Leti and HORIBA Scientific to Host Webinar on Ultrafast Characterization Tool: Plasma Profiling Time-of-Flight Mass Spectrometer Tool Cuts Optimization Time In Layer Deposition and Fabrication of Wide Range of Applications March 27th, 2017

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Govt.-Legislation/Regulation/Funding/Policy

A big leap toward tinier lines: Self-assembly technique could lead to long-awaited, simple method for making smaller microchip patterns March 27th, 2017

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Possible Futures

Information storage with a nanoscale twist: Discovery of a novel rotational force inside magnetic vortices makes it easier to design ultrahigh capacity disk drives March 28th, 2017

A big leap toward tinier lines: Self-assembly technique could lead to long-awaited, simple method for making smaller microchip patterns March 27th, 2017

ATTOPSEMI Technology Joins FDXcelerator Program to Deliver Advanced Non-Volatile Memory IP to GLOBALFOUNDRIES 22 FDX Technology Platform: Leading-edge I-fuse brings higher reliability, smaller cell size and ease of programmability for consumer, automotive, and IoT applications March 27th, 2017

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Academic/Education

AIM Photonics Welcomes Coventor as Newest Member: US-Backed Initiative Taps Process Modeling Specialist to Enable Manufacturing of High-Yield, High-Performance Integrated Photonic Designs March 16th, 2017

Nominations Invited for $250,000 Kabiller Prize in Nanoscience: Major international prize recognizes a visionary nanotechnology researcher February 20th, 2017

Oxford Nanoimaging report on how the Nanoimager, a desktop microscope delivering single molecule, super-resolution performance, is being applied at the MRC Centre for Molecular Bacteriology & Infection November 22nd, 2016

The University of Applied Sciences in Upper Austria uses Deben tensile stages as an integral part of their computed tomography research and testing facility October 18th, 2016

Chip Technology

A big leap toward tinier lines: Self-assembly technique could lead to long-awaited, simple method for making smaller microchip patterns March 27th, 2017

ATTOPSEMI Technology Joins FDXcelerator Program to Deliver Advanced Non-Volatile Memory IP to GLOBALFOUNDRIES 22 FDX Technology Platform: Leading-edge I-fuse brings higher reliability, smaller cell size and ease of programmability for consumer, automotive, and IoT applications March 27th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Scientists discover new 'boat' form of promising semiconductor: GeSe Uncommon form attenuates semiconductor's band gap size March 23rd, 2017

Nanotubes/Buckyballs/Fullerenes

Intertronics introduce new nanoparticle deagglomeration technology March 15th, 2017

Boron atoms stretch out, gain new powers: Rice University simulations demonstrate 1-D material's stiffness, electrical versatility January 26th, 2017

New stem cell technique shows promise for bone repair January 25th, 2017

Captured on video: DNA nanotubes build a bridge between 2 molecular posts: Research may lead to new lines of direct communication with cells January 9th, 2017

Nanoelectronics

A big leap toward tinier lines: Self-assembly technique could lead to long-awaited, simple method for making smaller microchip patterns March 27th, 2017

Scientists discover new 'boat' form of promising semiconductor: GeSe Uncommon form attenuates semiconductor's band gap size March 23rd, 2017

UC researchers use gold coating to control luminescence of nanowires: University of Cincinnati physicists manipulate nanowire semiconductors in pursuit of making electronics smaller, faster and cheaper March 17th, 2017

A SOI wafer is a suitable substrate for gallium nitride crystals: Improved characteristics in power electronics and radio applications can be achieved by using a SOI wafer for gallium nitride growth March 4th, 2017

Announcements

Information storage with a nanoscale twist: Discovery of a novel rotational force inside magnetic vortices makes it easier to design ultrahigh capacity disk drives March 28th, 2017

ATTOPSEMI Technology Joins FDXcelerator Program to Deliver Advanced Non-Volatile Memory IP to GLOBALFOUNDRIES 22 FDX Technology Platform: Leading-edge I-fuse brings higher reliability, smaller cell size and ease of programmability for consumer, automotive, and IoT applications March 27th, 2017

Leti and HORIBA Scientific to Host Webinar on Ultrafast Characterization Tool: Plasma Profiling Time-of-Flight Mass Spectrometer Tool Cuts Optimization Time In Layer Deposition and Fabrication of Wide Range of Applications March 27th, 2017

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Research partnerships

A big leap toward tinier lines: Self-assembly technique could lead to long-awaited, simple method for making smaller microchip patterns March 27th, 2017

ATTOPSEMI Technology Joins FDXcelerator Program to Deliver Advanced Non-Volatile Memory IP to GLOBALFOUNDRIES 22 FDX Technology Platform: Leading-edge I-fuse brings higher reliability, smaller cell size and ease of programmability for consumer, automotive, and IoT applications March 27th, 2017

Leti and HORIBA Scientific to Host Webinar on Ultrafast Characterization Tool: Plasma Profiling Time-of-Flight Mass Spectrometer Tool Cuts Optimization Time In Layer Deposition and Fabrication of Wide Range of Applications March 27th, 2017

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 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