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

SEMATECH to Address Critical Supply Chain Challenges and Present Latest Technology Advances at SEMICON West 2013 June 17th, 2013

An Innovative material for the Green Earth: Simple and inexpensive process to make a material for CO2 adsorption June 17th, 2013

Polymer-coated catalyst protects "artificial leaf" June 17th, 2013

Efficient and inexpensive: Researchers develop catalyst material for fuel cells: Platinum-nickel nano-octahedra save 90 percent platinum June 17th, 2013

Govt.-Legislation/Regulation/Funding/Policy

Working backward: Computer-aided design of zeolite templates: Rice scientists apply drug-design lessons to production of industrial minerals June 17th, 2013

An Innovative material for the Green Earth: Simple and inexpensive process to make a material for CO2 adsorption June 17th, 2013

Nanoparticle Opens the Door to Clean-Energy Alternatives June 14th, 2013

Discovery of new material state counterintuitive to laws of physics June 14th, 2013

Possible Futures

Space Solar Power: Key to a Livable Planet Earth June 10th, 2013

Global Nanotechnology Drug Delivery Market 2012-2016 June 10th, 2013

Nanorobot tetanus treatment animation June 9th, 2013

New horizons to drive the future of Medicine: European Technology Platform on Nanomedicine intends to lead the domain June 8th, 2013

Academic/Education

CNSE Welcomes Record Number of Students, Majority of Whom are New Yorkers, for Prestigious Summer Internship Program June 12th, 2013

FEI and University of Oklahoma Begin Collaboration Research Agreement for Understanding and Developing Unconventional Oil and Gas Reservoirs: Collaboration effort will focus on new methods to classify shales in the economic assessment of “tight” resource plays June 7th, 2013

Johannes Gutenberg University Mainz obtains new Collaborative Research Center on "Nanodimensional polymer therapeutics for tumor therapy" June 2nd, 2013

Lorraine University uses Nanoparticle Tracking Analysis to characterize biomolecules for agrichemicals, pharmacology and cosmetics May 28th, 2013

Chip Technology

SEMATECH to Address Critical Supply Chain Challenges and Present Latest Technology Advances at SEMICON West 2013 June 17th, 2013

Imec shows multiple enhancement options for next-generation FinFETs: Leading nano-electronics R&D center addresses key challenges of Germanium finFET technology at VLSI 2013 June 14th, 2013

Imec showcases innovation in RRAM R&D at VLSI Technology Symposium June 14th, 2013

Controlling magnetic clouds in graphene June 14th, 2013

Nanotubes/Buckyballs

Unzipped nanotubes unlock potential for batteries: Rice University lab combines graphene nanoribbons with tin oxide for improved anodes June 13th, 2013

The Diabetes ‘Breathalyzer’: Pitt chemists demonstrate sensor technology that could detect and monitor diabetes through breath analysis alone June 10th, 2013

Los Alamos catalyst could jumpstart e-cars, green energy: The new material has the highest oxygen reduction reaction (ORR) activity in alkaline media of any non-precious metal catalyst developed to date June 4th, 2013

Even with Defects, Graphene is Strongest Material in the World: New Study Reveals Strength of CVD Graphene May 31st, 2013

Nanoelectronics

Imec shows multiple enhancement options for next-generation FinFETs: Leading nano-electronics R&D center addresses key challenges of Germanium finFET technology at VLSI 2013 June 14th, 2013

Controlling magnetic clouds in graphene June 14th, 2013

Spot-welding graphene nanoribbons atom by atom June 13th, 2013

World's first large(wafer)-scale production of III-V semiconductor nanowire June 10th, 2013

Announcements

An Innovative material for the Green Earth: Simple and inexpensive process to make a material for CO2 adsorption June 17th, 2013

Polymer-coated catalyst protects "artificial leaf" June 17th, 2013

Efficient and inexpensive: Researchers develop catalyst material for fuel cells: Platinum-nickel nano-octahedra save 90 percent platinum June 17th, 2013

AXEON Acquires Assets of Leading Reverse Osmosis Systems Manufacturer June 17th, 2013

Research partnerships

Nano-thermometer enables first atomic-scale heat transfer measurements June 13th, 2013

New quantum dot technique combines best of optical and electron microscopy June 12th, 2013

2-D electronics take a step forward: Rice, Oak Ridge labs make semiconducting films for atom-thick circuits June 10th, 2013

World's first large(wafer)-scale production of III-V semiconductor nanowire June 10th, 2013

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








abbigliamento uomo
Computer Accessories
© Copyright 1999-2013 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE