WSU scientists convert baby powder chemical for use as light emitting source


Zinc oxide, a product used for decades in baby powder, has a bright future as a light source, according to David Look, Ph.D., a senior research physicist and director of the Semiconductor Research Center at Wright State University.

Look just returned from Japan, where he presented findings on his zinc oxide research at the Third International Workshop on Zinc Oxide. Approximately 200 scientists from around the world attended the event, where Look was honored with selection for the opening presentation of the conference.

"In powder form, zinc oxide has been used for years as a main ingredient in baby powder, but our research has shown an application for this chemical in crystal form as a source to emit light," said the scientist, a researcher at Wright State since 1980. He and his colleagues have produced more than 50 scientific papers on this work, and he has been invited to give seven worldwide presentations on the topic in the past year.

"Zinc oxide applications are a hot topic right now in the scientific community because it is at the cutting edge," he explained. "Zinc oxide crystals can take electrical power or battery power and convert this to light. It is exciting research."

Look said the long-term ramifications of this research are significant. "In 20 to 30 years all artificial light will be replaced by zinc oxide or a related chemical, gallium nitride. The estimated power savings over tungsten light in the U.S. alone would be $12 billion a year. Light bulbs from this new source can last for 100,000 hours, and the chemical is very cheap and safe to work with because it is non-toxic and presents no danger."

He said gallium nitride is already used in applications where longevity is important and price isn't the dominant factor. This includes traffic lights and the light systems on airplanes and expensive cars.

However, Look said a problem with zinc oxide that he and other scientists are exploring is that in crystal form it must be able to transmit both negative and positive current, and scientists haven't yet fully developed the positive current transmission. This problem was the heart of his presentation in Japan and is an area he and colleagues at the Air Force Research Laboratory at Wright-Patterson Air Force Base have been researching for four years.

Look organized the First International Workshop on Zinc Oxide at Wright State in 1999. That event attracted some 75 scientists in such fields as physics, chemistry and electrical engineering. This total increased at subsequent workshops to the 200 figure at Sendai, Japan, on Oct. 5-8. His new research on light emitting material also was recently selected as the dominant emerging research front in physics by the prestigious Thompson Institute for Scientific Information.

Look said other long-term applications of zinc oxide in crystal form include the CD/DVD and laser printer industries, because a zinc oxide ultraviolet laser could increase the capacity on CD/DVD disks some 15 times and would greatly increase the resolution of laser printers. His group of scientists in 1996 was one of the first to show the potential of laser applications for zinc oxide crystals. There also are military and homeland security applications, which Look studies with Air Force colleagues.

He receives research funding from the Navy, Air Force, NASA and industrial sources. The scientist is currently working with Wright-Patterson Air Force Base researchers on a five-year contract involving $8.5 million.

"Our work here at Wright State and with the Air Force Research Laboratory has put Dayton on the scientific map as one of the premier locations in the world for zinc oxide crystal research," he concluded.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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