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2008 News Releases

Longwood physics professor, two colleagues awarded National Science Foundation grant for research

June 9, 2008

Dr. Chris Moore, assistant professor of physics. Dr. Christopher Moore, assistant professor of physics, and two colleagues received a National Science Foundation grant for a research project.

A Longwood University physics professor and two colleagues recently received a National Science Foundation grant for a research project that could help improve technology for high-density optical discs and PlayStation games.

The $307,474 grant will allow Dr. Christopher Moore, assistant professor of physics at Longwood, and Dr. Alison Baski and Dr. Michael Reshchikov of Virginia Commonwealth University to study how the surfaces of the semiconductors gallium nitride (GaN) and zinc oxide (ZnO) affect their electrical and optical properties. Some $51,133 will go toward the Longwood portion of the project, which is an outgrowth of Moore’s doctoral dissertation.

The three-year grant started June 1 and will pay for the work of at least one and possibly two Longwood students during the summers of 2008, 2009 and 2010. A Longwood physics major, Sean Kenny, will work on the project this summer, mostly at VCU. He will look at defects on gallium nitride surfaces.

"We will grow zinc oxide nanowires here at Longwood, though most of the characterization, which is looking at them to see their length, diameter and electrical properties, will be done at VCU," said Moore. "This will be my job during the next three summers, and I’ll also work on the project during the academic year. Gallium nitride samples will be made at VCU, where three students (two graduate and one undergraduate) will work on the project. We are studying the materials on which technology such as Sony’s Blu-ray Disc and the newer PlayStation games, such as PlayStation 3, are based."

Gallium nitride and zinc oxide have gained "unprecedented attention due to their unique applications in blue laser and light emitting diodes, optical detectors, high-power amplifiers and chemical/gas sensing," Moore said. "Specifically, GaN has been used in the fabrication of blue and ultra-violet lasers that serve as the foundation for technologies such as Sony’s Blu-ray. Progress, however, is still challenged by the high density of defects in GaN and the lack of reliable p-type doping for ZnO, which is crucial to building devices such as diodes."

The defects, which appear as spots, will be examined in an atomic force microscope built several years ago by a Longwood chemistry professor, Dr. Keith Rider. "The diameter of gallium nitride defects is 10,000 times smaller than the diameter of a human hair," Moore said. "In a good sample, there about one billion defects per square centimeter. Some have 100 billion defects per square centimeter. Sean will be looking at how they behave electronically at different temperatures. So far they have been examined at room temperature."

"Another important issue, although sometimes neglected, is the role played by surfaces and interfaces in the electrical and optical properties of these semiconductors. Such surface-related effects can result in the reduced efficiency of emitters, shorter laser operation lifetimes, and earlier degradation of electronic devices. The investigations funded by this grant will provide a fundamental understanding of surface effects in semiconductors by studying their optical and electrical properties. This should lead to higher reliability, longer lifetime and higher efficiency bright light sources."

Baski, associate professor of physics and chair of VCU’s Department of Physics, is the project’s principal investigator, and Reshchikov, assistant professor of physics at VCU, and Moore are co-principal investigators. "It’s a collaborative team effort," Moore said. Baski was his Ph.D. adviser.

"Part of the grant is using a new technique that Dr. Baski and I developed as part of my dissertation, in which I combined two techniques in a novel way," said Moore. "We stumbled on this technique, which is how research often works. The splintering off is what makes research fun."

Moore is a chemical physicist who has conducted research on semiconductors for more than five years and has published about a dozen scientific articles on similar research. Many of the articles include undergraduate co-authors.

"This is another step forward in our efforts to become a national leader in undergraduate research and creative activities," said Dr. Charles Ross, dean of Longwood’s Cook-Cole College of Arts and Sciences.

The grant is from the NSF’s Division of Materials Research, which funds only 22 percent of grant proposals, said Moore, who came to Longwood in 2007 after teaching at St. Catherine’s School and J.R. Tucker High School in Richmond.

Interestingly, Sean Kenny, the Longwood student who will be involved in the project, was a student at J.R. Tucker when Moore was teaching there. "I never had him in my class, though I did have a student, now a VCU graduate student, who is also working on the project," Moore said.