Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


ORNL finding has materials scientists entering new territory

Solar cells, light emitting diodes, displays and other electronic devices could get a bump in performance because of a discovery at the Department of Energy's Oak Ridge National Laboratory that establishes new boundaries for controlling band gaps.

While complex transition metal oxides have for years held great promise for a variety of information and energy applications, the challenge has been to devise a method to reduce band gaps of those insulators without compromising the material's useful physical properties.

The band gap is a major factor in determining electrical conductivity in a material and directly determines the upper wavelength limit of light absorption. Thus, achieving wide band gap tunability is highly desirable for developing opto-electronic devices and energy materials.

Using a layer-by-layer growth technique for which Ho Nyung Lee of ORNL earned the Presidential Early Career Award for Scientists and Engineers, Lee and colleagues have achieved a 30 percent reduction in the band gap of complex metal oxides. The findings are outlined in the journal Nature Communications.

"Our approach to tuning band gaps is based on atomic-scale growth control of complex oxide materials, yielding novel artificial materials that do not exist in nature," Lee said. "This 'epitaxy' technique can be used to design entirely new materials or to specifically modify the composition of thin-film crystals with sub-nanometer accuracy."

While band gap tuning has been widely successful for more conventional semiconductors, the 30 percent band gap reduction demonstrated with oxides easily surpasses previous accomplishments of 6 percent – or 0.2 electron volt – in this area and opens pathways to new approaches to controlling band gap in complex-oxide materials.

With this discovery, the potential exists for oxides with band gaps to be continuously controlled over 1 electron volt by site-specific alloying developed by the ORNL team. "Therefore," Lee said, "this work represents a major achievement using complex oxides that offer a number of advantages as they are very stable under extreme and severe environments."

ORNL's Michelle Buchanan, associate lab director for the Physical Sciences Directorate, expanded on Lee's sentiment. "This work exemplifies how basic research can provide technical breakthroughs that will result in vastly improved energy technologies," she said.

Other authors of the paper, titled "Wide band gap tunability in complex transition metal oxides by site-specific substitution," are Woo Seok Choi, Matthew Chisholm, David Singh, Taekjib Choi and Gerald Jellison of ORNL's Materials Science and Technology Division. A patent is pending for this technology.

The research was funded initially by the Laboratory Directed Research and Development program and later by the Department of Energy's Office of Science. Optical measurements were performed in part at the Center for Nanophase Materials Sciences, a DOE-BES user facility at ORNL.

UT-Battelle manages ORNL for the Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit

Ron Walli | EurekAlert!
Further information:

More articles from Materials Sciences:

nachricht Study explains strength gap between graphene, carbon fiber
20.10.2016 | Rice University

nachricht Scientists develop a semiconductor nanocomposite material that moves in response to light
18.10.2016 | Worcester Polytechnic Institute

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

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

Innovative technique for shaping light could solve bandwidth crunch

20.10.2016 | Physics and Astronomy

Finding the lightest superdeformed triaxial atomic nucleus

20.10.2016 | Physics and Astronomy

NASA's MAVEN mission observes ups and downs of water escape from Mars

20.10.2016 | Physics and Astronomy

More VideoLinks >>>