Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

MIT chemist studies how electrons behave

29.11.2006
Work could improve lights, other devices

Troy Van Voorhis likes to watch how things work. This natural curiosity led to his current research on the behavior of electrons and how they function in various molecular systems, including artificial photosynthesis. The theories and simulations he and his team create may help lead to improvements in devices such as electronics, solar cells and lighting.

Now the MIT assistant professor of chemistry will have more opportunities to explore new simulations. Van Voorhis is one of 20 promising researchers recently awarded the 2006 David and Lucile Packard Foundation fellowship. He will receive an unrestricted research grant of $625,000 over five years.

"This frees me long-term to develop methods to make reliable predictions about the transfer of electrons, which is the most basic chemical reaction," said Van Voorhis, 30. "It is difficult to simulate the changes in electronic structure that accompany electron transfer, because a reaction pushes the electrons out of equilibrium, and current techniques for describing this are not adequate."

Van Voorhis and his team are developing methods and computer software that can simulate what happens when a dot in a light-emitting diode (LED) of a computer display turns on. In the case of an optical LED, positive and negative charges are strongly attracted to one another and become trapped. The unusual rules of quantum physics dictate that the charges can only recombine to emit light if they are spinning in opposite directions. As a result, typically only 25 percent of the trapped charges produce light; the other 75 percent of the charges spin in the same direction and are essentially wasted.

Van Voorhis and his colleagues have developed a computer program that simulates how these coupled spinning charges are nudged to react and thus emit light. The simulations indicate that the emission will increase if some of the charges spinning in one direction can be turned into charges spinning in the opposite direction and then form stable pairs.

"This situation could be selectively created in optical LEDs to improve the efficiency of a device such as a display," he said.

There are also potential applications of these visualization techniques to electronic devices, pharmaceuticals, energy and other fields, but they still are far off in the future.

Another big challenge being tackled by the Van Voorhis group is understanding and simulating the process of photosynthesis. In plant photosynthesis, light reacts with carbon dioxide and water to produce sugar and oxygen, which humans can later burn to produce energy. The knowledge of how to artificially mimic a process like photosynthesis could help scientists figure out a way to efficiently store solar energy in molecules that last for long periods.

The challenge is that the bonds being broken in any photosynthetic process are very strong. By breaking these strong bonds and forming weaker ones, molecules with higher energy are created. These molecules store the energy harvested from sunlight, and this energy is later released when the high-energy molecules are burned. However, current methods for artificial photosynthesis waste too much energy in breaking the strong bonds. Van Voorhis hopes to understand how to break bonds more efficiently so that a larger portion of the valuable energy is stored in the product molecules.

"We only have a partial knowledge of what is going on in photosynthesis," Van Voorhis said. "If you don't know exactly how something works, you don't know how to improve it."

To improve this state of affairs, his lab has been studying how electrons create and destroy chemical bonds. The new funding from the Packard Fellowship will allow him to move to the next step and start researching how to get light to turn into energy that won't escape as heat.

Elizabeth A. Thomson | MIT News Office
Further information:
http://www.mit.edu
http://web.mit.edu/newsoffice/2006/vanvoorhis.html

Further reports about: IMPROVE Voorhis bonds direction photosynthesis spinning

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>