Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New plasma transistor could create sharper displays

05.02.2009
By integrating a solid-state electron emitter and a microcavity plasma device, researchers at the University of Illinois have created a plasma transistor that could be used to make lighter, less expensive and higher resolution flat-panel displays.

“The new device is capable of controlling both the plasma conduction current and the light emission with an emitter voltage of 5 volts or less,” said Gary Eden, a professor of electrical and computer engineering, and director of the Laboratory for Optical Physics and Engineering at the U. of I.

At the heart of the plasma transistor is a microcavity plasma, an electronic-photonic device in which an electrically charged gas (a plasma) is contained within a microscopic cavity. Power is supplied by two electrodes at voltages of up to 200 volts.

Eden and graduate student Kuo-Feng (Kevin) Chen fabricated the plasma transistor from copper-clad laminate into which a microcavity 500 microns in diameter was produced by standard photolithographic techniques. The solid-state electron emitter was made from a silicon wafer, topped with a thin layer of silicon dioxide.

The microcavity is approximately the diameter of a human hair, and is filled with a small amount of gas. When excited by electrons, atoms in the plasma radiate light. The color of light depends on what gas is placed in the microcavity. Neon emits red light, for example, and argon emits blue light.

Around the plasma is a thin boundary layer called the sheath. Within the sheath, electrical current is carried not by negatively charged electrons, but instead by positively charged ions. Much heavier than electrons and therefore harder to accelerate, the ions require a large electric field generated by a large voltage drop across the sheath.

The intense electric field within the plasma sheath also promotes electron transport, said Eden, who also is a researcher at the university’s Coordinated Science Laboratory and at the Micro and Nanotechnology Laboratory. “By injecting electrons from the emitter into the sheath, we can significantly increase the flow of electrons through the plasma, which increases the plasma’s conductivity and light emission.”

While the microcavity plasma still requires up to 200 volts to emit light and conduct current, the current and light emission can be controlled by an electron emitter operating at 5 volts or less, Eden said. The current that is sent through the sheath to the bulk plasma determines how much current is carried by the two electrodes driving the microplasma.

In previous work, Eden’s team created flat-panel plasma lamps out of two sheets of aluminum foil separated by a thin dielectric layer of clear aluminum oxide. More than 250,000 lamps can be packed into a single panel. And, because microcavity plasmas operate at atmospheric pressure, thick pieces of glass are not needed to seal them. The lightweight plasma panels are less than 1 millimeter thick.

“Being able to control each microcavity plasma independently could turn our plasma panel into a less expensive and higher resolution plasma display,” Eden said. “The plasma transistor also could be used in applications where you want to use a small voltage to control a great deal of power.”

Eden and Chen described the plasma transistor in the journal Applied Physics Letters. The researchers have applied for a patent.

The work was supported by the U.S. Air Force Office of Scientific Research.

James E. Kloeppel | University of Illinois
Further information:
http://www.illinois.edu
http://news.illinois.edu/news/09/0204transistor.html

More articles from Physics and Astronomy:

nachricht New NASA study improves search for habitable worlds
20.10.2017 | NASA/Goddard Space Flight Center

nachricht Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>