Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New research expected to improve laser devices and make photovoltaics more efficient

17.11.2008
University of Chicago scientists have induced electrons in the nanocrystals of semiconductors to cool more slowly by forcing them into a smaller volume. This has the potential to improve satellite communications and the generation of solar power.

"Slowing down the cooling of these electrons—in this case, by more than 30 times—could lead to a better infrared laser source," said Philippe Guyot-Sionnest, Professor of Chemistry and Physics at the University of Chicago. "This, in turn, could be used to increase the bandwidth of communication satellites, allowing for faster connections."

Guyot-Sionnest is the principal investigator on the research project, which was described in a paper called "Slow Electron Cooling in Colloidal Quantum Dots," published Nov. 7 in Science.

The slow cooling of electrons in nanocrystals could lead to better, more efficient photovoltaic devices, he added. "This is because proposals to devise ways to extract the excess heat from these electrons as they cool are more likely to be realized—and to work—due to the fact that we now understand better what is going on with these nanocrystals."

Slower cooling of electrons in nanocrystals was first theorized in 1990, but no one has been able to observe this effect.

Slow electron cooling in nanocrystals occurs because forcing the electrons into a smaller volume leads them to oscillate between their alternate extremes within a very short period of time. (This is analogous to the way shorter strings on musical instruments produce higher pitches.) The electrons in the nanocrystals used in this experiment oscillated so fast that it became difficult for them to drag along the more sluggish vibrations of the nuclei. As a result, the energy stayed with the electrons for a longer period of time.

The slower cooling effect was difficult to induce and observe because several different mechanisms for energy loss interfered with the process. By eliminating these other mechanisms, the researchers were able to induce and observe slower electron cooling in nanocrystals.

Anshu Pandey, a graduate student in Chemistry at the University of Chicago, did the experiments described in the Science paper, which he co-authored.

Greg Borzo | EurekAlert!
Further information:
http://www.uchicago.edu

More articles from Life Sciences:

nachricht Bolstering fat cells offers potential new leukemia treatment
17.10.2017 | McMaster University

nachricht Ocean atmosphere rife with microbes
17.10.2017 | King Abdullah University of Science & Technology (KAUST)

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

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>