Featured Research

from universities, journals, and other organizations

New spin on old method to develop more efficient electronics

Date:
July 1, 2012
Source:
University of Pittsburgh
Summary:
With the advent of semiconductor transistors -- invented in 1947 as a replacement for bulky and inefficient vacuum tubes -- has come the consistent demand for faster, more energy-efficient technologies. To fill this need, researchers are proposing a new spin on an old method: a switch from the use of silicon electronics back to vacuums as a medium for electron transport -- exhibiting a significant paradigm shift in electronics.

With the advent of semiconductor transistors -- invented in 1947 as a replacement for bulky and inefficient vacuum tubes -- has come the consistent demand for faster, more energy-efficient technologies. To fill this need, researchers at the University of Pittsburgh are proposing a new spin on an old method: a switch from the use of silicon electronics back to vacuums as a medium for electron transport -- exhibiting a significant paradigm shift in electronics.

Their findings were published online in Nature Nanotechnology July 1.

For the past 40 years, the number of transistors placed on integrated circuit boards in devices like computers and smartphones has doubled every two years, producing faster and more efficient machines. This doubling effect, commonly known as "Moore's Law," occurred by scientists' ability to continually shrink the transistor size, thus producing computer chips with all-around better performance. However, as transistor sizes have approached lower nanometer scales, it's become increasingly difficult and expensive to extend Moore's Law further.

"Physical barriers are blocking scientists from achieving more efficient electronics," said Hong Koo Kim, principal investigator on the project and Bell of Pennsylvania/Bell Atlantic Professor in the University of Pittsburgh's Swanson School of Engineering. "We worked toward solving that road block by investigating transistors and its predecessor -- the vacuum."

The ultimate limit of transistor speed, says Kim, is determined by the "electron transit time," or the time it takes an electron to travel from one device to the other. Electrons traveling inside a semiconductor device frequently experience collisions or scattering in the solid-state medium. Kim likens this to driving a vehicle on a bumpy road -- cars cannot speed up very much. Likewise, the electron energy needed to produce faster electronics is hindered.

"The best way to avoid this scattering -- or traffic jam -- would be to use no medium at all, like vacuum or the air in a nanometer scale space," said Kim. "Think of it as an airplane in the sky creating an unobstructed journey to its destination."

However, says Kim, conventional vacuum electronic devices require high voltage, and they aren't compatible with many applications. Therefore, his team decided to redesign the structure of the vacuum electronic device altogether. With the assistance of Siwapon Srisonphan, a Pitt PhD candidate, and Yun Suk Jung, a Pitt postdoctoral fellow in electrical and computer engineering, Kim and his team discovered that electrons trapped inside a semiconductor at the interface with an oxide or metal layer can be easily extracted out into the air. The electrons harbored at the interface form a sheet of charges, called two-dimensional electron gas. Kim found that the Coulombic repulsion -- the interaction between electrically charged particles -- in the electron layer enables the easy emission of electrons out of silicon. The team extracted electrons from the silicon structure efficiently by applying a negligible amount of voltage and then placed them in the air, allowing them to travel ballistically in a nanometer-scale channel without any collisions or scattering.

"The emission of this electron system into vacuum channels could enable a new class of low-power, high-speed transistors, and it's also compatible with current silicon electronics, complementing those electronics by adding new functions that are faster and more energy efficient due to the low voltage," said Kim.

With this finding, he says, there is the potential for the vacuum transistor concept to come back, but in a fundamentally different and improved way.


Story Source:

The above story is based on materials provided by University of Pittsburgh. Note: Materials may be edited for content and length.


Journal Reference:

  1. Siwapon Srisonphan, Yun Suk Jung, Hong Koo Kim. Metal–oxide–semiconductor field-effect transistor with a vacuum channel. Nature Nanotechnology, 2012; DOI: 10.1038/nnano.2012.107

Cite This Page:

University of Pittsburgh. "New spin on old method to develop more efficient electronics." ScienceDaily. ScienceDaily, 1 July 2012. <www.sciencedaily.com/releases/2012/07/120701191615.htm>.
University of Pittsburgh. (2012, July 1). New spin on old method to develop more efficient electronics. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2012/07/120701191615.htm
University of Pittsburgh. "New spin on old method to develop more efficient electronics." ScienceDaily. www.sciencedaily.com/releases/2012/07/120701191615.htm (accessed July 23, 2014).

Share This




More Matter & Energy News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
Powered by NewsLook.com
Boeing Ups Outlook on 52% Profit Jump

Boeing Ups Outlook on 52% Profit Jump

Reuters - Business Video Online (July 23, 2014) Commercial aircraft deliveries rose seven percent at Boeing, prompting the aerospace company to boost full-year profit guidance- though quarterly revenues missed analyst estimates. Bobbi Rebell reports. Video provided by Reuters
Powered by NewsLook.com
Europe's Car Market on the Rebound?

Europe's Car Market on the Rebound?

Reuters - Business Video Online (July 23, 2014) Daimler kicks off a round of second-quarter earnings results from Europe's top carmakers with a healthy set of numbers - prompting hopes that stronger sales in Europe will counter weakness in emerging markets. Hayley Platt reports. Video provided by Reuters
Powered by NewsLook.com
9/11 Commission Members Warn of Terror "fatigue" Among American Public

9/11 Commission Members Warn of Terror "fatigue" Among American Public

Reuters - US Online Video (July 22, 2014) Ten years after releasing its initial report, members of the 9/11 Commission warn of the "waning sense of urgency" in combating terrorists attacks. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins