Featured Research

from universities, journals, and other organizations

Electron billiards in nanoscale circuits

Date:
October 24, 2010
Source:
Technische Universitaet Muenchen
Summary:
In solar cells, solar radiation boosts electrons to higher energy states, thereby releasing them from their atomic bonds as electricity begins to flow. Scientists have now developed a novel method to analyze the way photogenerated electrons move in the smallest photodetectors.

Cirquit with quantum point contacts.
Credit: Image courtesy of Technische Universitaet Muenchen

In solar cells, solar radiation boosts electrons to higher energy states, thereby releasing them from their atomic bonds as electricity begins to flow. Scientists led by Professor Alexander Holleitner, physicist at the Technische Universitδt Muenchen (TUM), have developed a novel method to analyze the way photogenerated electrons move in the smallest photodetectors.

Related Articles


At the heart of the method is a so-called quantum point contact (QPC). This is a narrow conductive channel in a semiconductor circuit. The scientists created a 70-nanometer narrow channel, about as wide as the wavelength of electrons in the semiconductor. The key is that only one electron at a time will fit through the channel, making possible extremely high-precision measurements of the electric current. As described in the current publication, this method was applied to photogenerated electrons for the first time ever.

In the experimental set-up it is not the sun, but rather a laser beam that kicks the electrons into their excited state. These electrons are then analyzed using a quantum point contact. In the process, the scientists were able to demonstrate for the first time that photogenerated electrons can flow several micrometers before colliding with crystalline atoms. They also established that the geometric form of a circuit has a strong influence on electron paths. Electrons can even "run around corners" when they rebound from circuit boundaries, not unlike billiard balls.

The insights and analytic opportunities made possible by this novel technique are relevant to a whole range of applications. These include, most notably, the further development of electronic components such as photodetectors, high electron mobility transistors (HEMT), and components that utilize the magnetic spin of electrons to process information.

Apart from Professor Holleitner's team, scientists working with Professor Joerg Kotthaus (Ludwig-Maximilians-Universitaet Muenchen) and Professor Peter Haenggi (Universitaet Augsburg) participated in the research. The studies were funded by the Cluster of Excellence Nanosystems Initiative Munich (NIM), the German Federal Ministry of Education and Research BMBF via nanoQUIT, the Deutsche Forschungsgemeinschaft (DFG Grant no. Ho 3324/4), the Center for NanoScience (CeNS), and LMUexcellent.


Story Source:

The above story is based on materials provided by Technische Universitaet Muenchen. Note: Materials may be edited for content and length.


Journal Reference:

  1. Klaus-Dieter Hof, Franz J. Kaiser, Markus Stallhofer, Dieter Schuh, Werner Wegscheider, Peter Hänggi, Sigmund Kohler, Jφrg P. Kotthaus, Alexander W. Holleitner. Spatially Resolved Ballistic Optoelectronic Transport Measured by Quantized Photocurrent Spectroscopy. Nano Letters, 2010; 10 (10): 3836 DOI: 10.1021/nl102068v

Cite This Page:

Technische Universitaet Muenchen. "Electron billiards in nanoscale circuits." ScienceDaily. ScienceDaily, 24 October 2010. <www.sciencedaily.com/releases/2010/10/101021190615.htm>.
Technische Universitaet Muenchen. (2010, October 24). Electron billiards in nanoscale circuits. ScienceDaily. Retrieved January 26, 2015 from www.sciencedaily.com/releases/2010/10/101021190615.htm
Technische Universitaet Muenchen. "Electron billiards in nanoscale circuits." ScienceDaily. www.sciencedaily.com/releases/2010/10/101021190615.htm (accessed January 26, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Monday, January 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Obama Reveals Nuclear Breakthrough on Landmark India Trip

Obama Reveals Nuclear Breakthrough on Landmark India Trip

Reuters - News Video Online (Jan. 25, 2015) — In a glow of bonhomie, U.S. President Barack Obama and Indian Prime Minister Narendra Modi unveil a deal aimed at unlocking billions of dollars in nuclear trade. Pavithra George reports. Video provided by Reuters
Powered by NewsLook.com
NTSB: Missing Planes' Black Boxes Should Transmit Wirelessly

NTSB: Missing Planes' Black Boxes Should Transmit Wirelessly

Newsy (Jan. 23, 2015) — In light of high-profile plane disappearances in the past year, the NTSB has called for changes to make finding missing aircraft easier. Video provided by Newsy
Powered by NewsLook.com
Iconic Metal Toy Meccano Goes Robotic

Iconic Metal Toy Meccano Goes Robotic

Reuters - Innovations Video Online (Jan. 22, 2015) — Classic children&apos;s toy Meccano has gone digital, releasing a programmable kit robot that can be controlled by voice recognition. The toymakers say Meccanoid G15 KS is easy to use and is compatible with existing Meccano pieces. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
The VueXL From VX1 Immersive Smartphone Headset!

The VueXL From VX1 Immersive Smartphone Headset!

Rumble (Jan. 22, 2015) — The VueXL from VX1 is a product that you install your smartphone in and with the magic of magnification lenses, enlarges your smartphones screen so that it&apos;s like looking at a big screen TV. Check it out! Video provided by Rumble
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins