Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Computer simulations: Finding the right mix

28.03.2014

Computer simulations indicate that mixing silicon with other materials improves the diversity of nanoscale electronic devices

The semiconductor silicon lies at the heart of the current revolution in electronics and computing. In particular, it can produce compact integrated circuits when processed by modern techniques capable of fabricating structures just a few nanometers in size.


Cross-sectional view of stable nanowires made from carbon–silicon (left), germanium–silicon (center) and tin–silicon (right), as predicted by calculations. The silicon atoms (yellow) are found at the edge of the nanowire when alloyed with tin (gray) and germanium (green). In contrast, in carbon–silicon nanowires (where carbon is indicated in black), they have an ordered arrangement.

© 2014 A*STAR Institute of High Performance Computing

The semiconductor silicon lies at the heart of the current revolution in electronics and computing. In particular, it can produce compact integrated circuits when processed by modern techniques capable of fabricating structures just a few nanometers in size.

Now, Man-Fai Ng and Teck Leong Tan at the A*STAR Institute of High Performance Computing in Singapore have shown that mixing silicon with similar materials can open the door to the fabrication of nanoscale devices with a diverse array of properties that have a wider range of applications1.

Now, Man-Fai Ng and Teck Leong Tan at the A*STAR Institute of High Performance Computing in Singapore have shown that mixing silicon with similar materials can open the door to the fabrication of nanoscale devices with a diverse array of properties that have a wider range of applications1.

Ng and Tan used state-of-the-art computer simulations to assess the structural stability and electronic properties of silicon-based nanowires. As their name suggests, nanowires are just a few nanometers wide but can be up to a millimeter long. They exhibit unusual electronic properties because their small width confines the motion of electrons across the wire.

The properties of silicon nanowires are well established, but there is considerable scope to expand their applicability. Scientists anticipate they could realize a more diverse range of characteristics by partially replacing silicon with other elements that are in the same column as silicon in the periodic table. There are many potential materials — including carbon, germanium and tin — each of which can be combined with silicon in any ratio to form an alloy.

Consequently, the total number of possible alloys is immense. The researchers thus undertook a comprehensive search of all these silicon-based alloys to determine which are atomically stable and which have the best properties for nanowire devices.

Ng and Tan employed three mathematical techniques (namely, density functional theory, the cluster expansion method and the Monte Carlo method) to simulate different atomic arrangements in nanowires.

“Instead of evaluating all possible alloy structures, our multiscaled simulation approach enabled rapid large-scale comparison of different combinations of alloy structures and selected the thermodynamically stable ones,” explained Ng.

The most stable germanium–silicon and tin–silicon nanowires were found to be those in which the silicon atoms are concentrated around the edge of the wire and the other atomic species are at the core. Conversely, an optimum carbon–silicon nanowire exhibited an ordered arrangement of the atomic species (see image).

Once they had identified the optimum atomic arrangement, Ng and Tan calculated the energy bandgap — a critical parameter for determining the electronic properties of semiconductors. “Next, we plan to improve the bandgap prediction for silicon-based nanowires and develop our approach to address more complicated nanosystems for energy applications,” says Ng.

The A*STAR-affiliated researchers contributing to this research are from the Institute of High Performance Computing 

Associated links

Journal information

Ng, M.-F. & Tan, T. L. Unveiling stable group IV alloy nanowires via a comprehensive search and their electronic band characteristics. Nano Letters 13, 4951−4956 (2013).

A*STAR Research | ResearchSEA News
Further information:
http://www.researchsea.com

More articles from Information Technology:

nachricht Superfast fluorescence sets new speed record
27.07.2015 | Duke University

nachricht Two crystals are better than one
22.07.2015 | The Agency for Science, Technology and Research (A*STAR)

All articles from Information Technology >>>

The most recent press releases about innovation >>>

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

Im Focus: Quantum Matter Stuck in Unrest

Using ultracold atoms trapped in light crystals, scientists from the MPQ, LMU, and the Weizmann Institute observe a novel state of matter that never thermalizes.

What happens if one mixes cold and hot water? After some initial dynamics, one is left with lukewarm water—the system has thermalized to a new thermal...

Im Focus: On the crest of the wave: Electronics on a time scale shorter than a cycle of light

Physicists from Regensburg and Marburg, Germany have succeeded in taking a slow-motion movie of speeding electrons in a solid driven by a strong light wave. In the process, they have unraveled a novel quantum phenomenon, which will be reported in the forthcoming edition of Nature.

The advent of ever faster electronics featuring clock rates up to the multiple-gigahertz range has revolutionized our day-to-day life. Researchers and...

Im Focus: Superfast fluorescence sets new speed record

Plasmonic device has speed and efficiency to serve optical computers

Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.

Im Focus: Unlocking the rice immune system

Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight

A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...

Im Focus: Smarter window materials can control light and energy

Researchers in the Cockrell School of Engineering at The University of Texas at Austin are one step closer to delivering smart windows with a new level of energy efficiency, engineering materials that allow windows to reveal light without transferring heat and, conversely, to block light while allowing heat transmission, as described in two new research papers.

By allowing indoor occupants to more precisely control the energy and sunlight passing through a window, the new materials could significantly reduce costs for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Euro Bio-inspired - International Conference and Exhibition on Bio-inspired Materials

23.07.2015 | Event News

Clash of Realities – International Conference on the Art, Technology and Theory of Digital Games

10.07.2015 | Event News

World Conference on Regenerative Medicine in Leipzig: Last chance to submit abstracts until 2 July

25.06.2015 | Event News

 
Latest News

Tool making and additive technology exhibition: Fraunhofer IPT at Formnext

31.07.2015 | Trade Fair News

First Siemens-built Thameslink train arrives in London

31.07.2015 | Transportation and Logistics

California 'rain debt' equal to average full year of precipitation

31.07.2015 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>