Back to Table of contents

Primeur weekly 2013-02-25

Exascale supercomputing

Indiana University receives grant for supercomputer work ...

The Cloud

Rackspace announces new data centre for expanding UK base ...

HP enables partners to accelerate Cloud Services delivery ...

Red Hat unveils Big Data and open hybrid Cloud direction ...

Cloud9 IDE builds on-line development environment with Red Hat OpenShift ...

EuroFlash

Modern museum techniques: projectiondesign helps visitors better comprehend the stories of First World War ...

Bern computer simulation helps to better understand the origin of our solar system ...

Advancing research collaboration with GÉANT's high-speed infrastructure ...

Partnership puts computational science at the heart of Unilever's R&D ...

USFlash

New Emerson Network Power media processing accelerator offers performance breakthrough in server applications ...

HP extends Converged Infrastructure leadership ...

HP delivers simplicity, profitability and consistency for partners ...

Introducing Intel Cache Acceleration Software for use with Intel SSD data centre family ...

ManTech announces financial results for fourth quarter and fiscal year 2012 ...

Mellanox FDR 56Gb/s InfiniBand accelerates the fastest supercomputer in India ...

Enterprises perform faster and operations run more efficiently on new NetApp high-end, Flash-optimized storage systems ...

NetApp expands Flash portfolio, extending leadership in enterprise Flash storage ...

NVIDIA introduces GeForce GTX TITAN: DNA of the world's fastest supercomputer, powered by world's fastest GPU ...

NREL and partners demonstrate quantum dots that assemble themselves ...

New supercomputer to aid genomics research ...

Supercomputers used to supercharge antioxidants ...

Supercomputer Titan could advance progress in development of solar energy at West Virginia University ...

NREL and partners demonstrate quantum dots that assemble themselves

19 Feb 2013 Washington D.C. - Scientists from the U.S. Department of Energy's National Renewable Energy Laboratory and other labs have demonstrated a process whereby quantum dots can self-assemble at optimal locations in nanowires, a breakthrough that could improve solar cells, quantum computing, and lighting devices. A paper on the new technology, "Self-assembled Quantum Dots in a Nanowire System for Quantum Photonics", appears in the current issue of the scientific journalNature Materials.

Quantum dots are tiny crystals of semiconductor a few billionths of a meter in diameter. At that size they exhibit beneficial behaviours of quantum physics such as forming electron-hole pairs and harvesting excess energy.

The scientists demonstrated how quantum dots can self-assemble at the apex of the gallium arsenide/aluminum gallium arsenide core/shell nanowire interface. Crucially, the quantum dots, besides being highly stable, can be positioned precisely relative to the nanowire's centre. That precision, combined with the materials' ability to provide quantum confinement for both the electrons and the holes, makes the approach a potential game-changer.

Electrons and holes typically locate in the lowest energy position within the confines of high-energy materials in the nanostructures. But in the new demonstration, the electron and hole, overlapping in a near-ideal way, are confined in the quantum dot itself at high energy rather than located at the lowest energy states. In this case, that's the gallium-arsenide core. It's like hitting the bulls-eye rather than the periphery.

The quantum dots, as a result, are very bright, spectrally narrow and highly anti-bunched, displaying excellent optical properties even when they are located just a few nanometers from the surface - a feature that even surprised the scientists.

"Some Swiss scientists announced that they had achieved this, but scientists at the conference had a hard time believing it", stated NREL senior scientist Jun-Wei Luo, one of the co-authors of the study. Jun-Wei Luo got to work constructing a quantum-dot-in-nanowire system using NREL's supercomputer and was able to demonstrate that despite the fact that the overall band edges are formed by the gallium Arsenide core, the thin aluminum-rich barriers provide quantum confinement both for the electrons and the holes inside the aluminum-poor quantum dot. That explains the origin of the highly unusual optical transitions.

Several practical applications are possible. The fact that stable quantum dots can be placed very close to the surface of the nanometers raises a huge potential for their use in detecting local electric and magnetic fields. The quantum dots also could be used to charge converters for better light-harvesting, as in the case of photovoltaic cells.

The team of scientists working on the project came from universities and laboratories in Sweden, Switzerland, Spain, and the United States.

NREL is the U.S. Department of Energy's primary national laboratory for renewable energy and energy efficiency research and development. NREL is operated for DOE by the Alliance for Sustainable Energy LLC.

Source: DOE/National Renewable Energy Laboratory

Back to Table of contents

Primeur weekly 2013-02-25

Exascale supercomputing

Indiana University receives grant for supercomputer work ...

The Cloud

Rackspace announces new data centre for expanding UK base ...

HP enables partners to accelerate Cloud Services delivery ...

Red Hat unveils Big Data and open hybrid Cloud direction ...

Cloud9 IDE builds on-line development environment with Red Hat OpenShift ...

EuroFlash

Modern museum techniques: projectiondesign helps visitors better comprehend the stories of First World War ...

Bern computer simulation helps to better understand the origin of our solar system ...

Advancing research collaboration with GÉANT's high-speed infrastructure ...

Partnership puts computational science at the heart of Unilever's R&D ...

USFlash

New Emerson Network Power media processing accelerator offers performance breakthrough in server applications ...

HP extends Converged Infrastructure leadership ...

HP delivers simplicity, profitability and consistency for partners ...

Introducing Intel Cache Acceleration Software for use with Intel SSD data centre family ...

ManTech announces financial results for fourth quarter and fiscal year 2012 ...

Mellanox FDR 56Gb/s InfiniBand accelerates the fastest supercomputer in India ...

Enterprises perform faster and operations run more efficiently on new NetApp high-end, Flash-optimized storage systems ...

NetApp expands Flash portfolio, extending leadership in enterprise Flash storage ...

NVIDIA introduces GeForce GTX TITAN: DNA of the world's fastest supercomputer, powered by world's fastest GPU ...

NREL and partners demonstrate quantum dots that assemble themselves ...

New supercomputer to aid genomics research ...

Supercomputers used to supercharge antioxidants ...

Supercomputer Titan could advance progress in development of solar energy at West Virginia University ...