Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Nanoscientists Provide New Picture of Semiconductor Material


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:

More articles from Physics and Astronomy:

nachricht First results of NSTX-U research operations
26.10.2016 | DOE/Princeton Plasma Physics Laboratory

nachricht Scientists discover particles similar to Majorana fermions
25.10.2016 | Chinese Academy of Sciences Headquarters

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: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

3-D-printed structures shrink when heated

26.10.2016 | Materials Sciences

Indian roadside refuse fires produce toxic rainbow

26.10.2016 | Health and Medicine

First results of NSTX-U research operations

26.10.2016 | Physics and Astronomy

More VideoLinks >>>