Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanoscientists Provide New Picture of Semiconductor Material

05.10.2005


For almost a decade, scientists thought they understood the surface structure of cubic gallium nitride, a promising new crystalline semiconductor. Research by an interdisciplinary team of nanoscientists from Ohio University and the Universitat Autònoma de Barcelona, however, turns that idea on its head.



Their study published in the Sept. 30 online issue of the journal Physical Review Letters provides a fresh – and they argue, more accurate – look at the surface structure of the crystalline material, which could be used in lasers and other electronic devices.

Nancy Sandler, an assistant professor of physics and astronomy at Ohio University, and Pablo Ordejón, a Barcelona professor specializing in the algorithm used in the project, calculated several properties using the currently accepted model and obtained new images of the crystal’s surface. Experimentalists Hamad Al-Brithen and his Ph.D. adviser Arthur Smith, Ohio University associate professor of physics and astronomy, recently had used scanning tunneling microscopy to capture an image of the surface.


When they compared the model image with the experimental image, the researchers found that the theory and the experiment aligned – except for one important detail. Researchers previously thought that the atoms on the surface were arranged in groups of four in one direction but only one in the other. The new finding shows that they are in groups of four in one direction but in groups of three in the other direction, Smith said. The discrepancy calls into question the model scientists have accepted for the last seven years and the understanding of the surface structure.

The surface of the material is not easy to work with, Smith noted, because it’s sensitive to how scientists handle it. A different structure could be created simply by exposing the crystalline surface to other elements. For example, the accidental contact of arsenic (an element commonly used in semiconductor growth) with the crystal surface has affected other researchers’ data in the past.

“The relevance of modeling surfaces is that the ordering of atoms on a surface can be substantially different from the one in the bulk of the material,” Sandler said.

The new research could help scientists learn how to use cubic gallium nitride as a new semiconductor for lasers and other electronic devices such as display technologies and bright blue light-emitting diode (LED) applications. It also may help them grow layers of the material more precisely to create technological applications. But before scientists can make use of this potentially valuable material, they first must understand its basic properties so they can begin tackling its drawbacks, said Smith, director of Ohio University’s Nanoscale and Quantum Phenomena Institute.

“Cubic gallium nitride is more difficult to grow [than the popular hexagonal type of gallium nitride crystal],” said Smith. “But its cubic properties make it more compatible with other commonly used materials, and so it has more potential for integration into mainstream devices.”

The research was supported by grants from the National Science Foundation and Spain’s Ministry of Science and Technology and its Ministry of Education and Science.

This project is the first major paper published by Ohio University’s Nanoscale Interdisciplinary Research Team, a collaboration of researchers funded by the NSF.

Andrea Gibson | EurekAlert!
Further information:
http://www.ohio.edu

More articles from Physics and Astronomy:

nachricht From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison

nachricht Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>