Category Physics

Unique Ferroelectric Microstructure revealed for first time

STEM image of polar nanoregions
An atomically resolved scanning transmission electron microscopy (STEM) image of the polar nanoregions (PNRs) embedded in the nonpolar matrix in the layered perovskite material (Ca, Sr)3Mn2O7. Bright contrast in the images can be directly interpreted as the atomic columns in the crystal. Aberration corrected STEM was employed to direct capture the arrangement of the atoms in the (a-type and b-type) polar nanoregions in the crystal and the displacement measurement at picometer precision were performed on the STEM images to extract the distortion in the structure. Credit: Alem Group/Jennifer M. McCann, MRI. All Rights Reserved.

A team of researchers have observed and reported for the first time the unique microstructure of a novel ferroelectric material, enabling the development of lead-...

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Modified Microwave oven cooks up Next-gen Semiconductors

James Hwang
James Hwang, research professor in the Department of Materials Science and Engineering, right, at his modified microwave with Gianluca Fabi holding a semiconductor at left. Ryan Young/Cornell University

A household microwave oven modified by a Cornell engineering professor is helping to cook up the next generation of cellphones, computers and other electronics after the invention was shown to overcome a major challenge faced by the semiconductor industry.

The research is detailed in a paper published in Applied Physics Letters. The lead author is James Hwang, a research professor in the department of materials science and engineering.

As microchips continue to shrink, silicon must be doped, or mixed, with higher concentrations of phosphorus to produce the desired current...

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Solar Energy breakthrough: Perovskite cell with Greater Stability, Efficiency

Photo shows the new perovskite solar cell.
The inverted architecture of this perovskite solar cell, coupled with surface engineering, enabled researchers to improve efficiency and stability. Photo from NREL

Researchers at the U.S. Department of Energy’s (DOE’s) National Renewable Energy Laboratory (NREL) made a technological breakthrough and constructed a perovskite solar cell with the dual benefits of being both highly efficient and highly stable.

The work was done in collaboration with scientists from the University of Toledo, the University of Colorado-Boulder, and the University of California-San Diego.

A unique architectural structure enabled the researchers to record a certified stabilized efficiency of 24% under 1-sun illumination, making it the highest reported of its kind...

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Researchers demonstrate New, More Energy-Efficient Devices using Gallium Nitride

Engineering researchers have created new high-power electronic devices that are more energy efficient than previous technologies. The devices are made possible by a unique technique for “doping” gallium nitride (GaN) in a controlled way.

“Many technologies require power conversion — where power is switched from one format to another,” says Dolar Khachariya, the first author of a paper on the work and a former Ph.D. student at North Carolina State University. “For example, the technology might need to convert AC to DC, or convert electricity into work — like an electric motor. And in any power conversion system, most power loss takes place at the power switch — which is an active component of the electrical circuit that makes the power conversion system.

“Developing more efficien...

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