submit news    HOME | FEEDBACK  


« NAVIGATION »
NEWS

- Bio/Medicine

- Chemicals

- Defense

- Drug Delivery

- Education

- Electronics

- Energy

- Events

- Grants

- Industry

- Investment

- Litigation

- Materials

- MEMS

- Nanofabrication

- Nanoparticles

- Nanotubes

- Optics

- Partnership

- Patent

- Products

- Quantum dots

- Research

- Smart Dust

- Software
COMPANIES
EVENTS

- Browse by Month

- Current Shows

- Previous Shows

- Submit Events
FEEDBACK
ADVERTISE
LINK TO US

« PARTNERS »
Become A Nanotechwire Partner

FEI Company

Veeco Instruments

Nano Science and Technology Institute

National Nanotechnology Initiative

Nanotechnology at Zyvex

Want to see your Company or Organization listed above? Become A Nanotechwire Partner Today - click here
« NEWSLETTER »



« SEARCH »







3/9/2011 11:08:05 AM
Ultra fast photodetectors out of carbon nanotubes

Carbon nanotubes have a multitude of unusual properties which make them promising candidates for optoelectronic components. However, so far it has proven extremely difficult to analyze or influence their optic and electronic properties. A team of researchers headed by Professor Alexander Holleitner, a physicist at the Technische Universitaet Muenchen and member of the Cluster of Excellence Nanosystems Munich (NIM), has now succeeded in developing a measurement method allowing a time-based resolution of the so-called photocurrent in photodetectors with picosecond precision.

"A picosecond is a very small time interval," explains Alexander Holleitner. "If electrons traveled at the speed of light, they would make it almost all the way to the moon in one second. In a picosecond they would only cover about a third of a millimeter." This new measurement technique is about a hundred times faster than any existing method. It allowed the scientists headed by Professor Alexander Holleitner to measure the precise speed of electrons. In the carbon nanotubes the electrons only cover a distance of about 8 ten-thousandths of a millimeter or 800 nanometers in one picosecond.

At the heart of the photodetectors in question are carbon tubes with a diameter of about one nanometer spanning a tiny gap between two gold detectors. The physicists measured the speed of the electrons by means of a special time-resolved laser spectroscopy process the pump-probe technique. It works by exciting electrons in the carbon nanotube by means of a laser pulse and observing the dynamics of the process using a second laser.

The insights and analytic opportunities made possible by the presented technique are relevant to a whole range of applications. These include, most notably, the further development of optoelectronic components such as nanoscale photodetectors, photo-switches and solar cells.

The studies were funded by the German Research Foundation (Cluster of Excellence Nanosystems Initiative Munich, NIM) and the Center for NanoScience (CeNS) at Ludwig-Maximilians-Universitaet Muenchen. Further contributions to the publication came from physicists of the University of Regensburg (Germany) and the Swiss Federal Institute of Technology, Zurich.

Original publication:

Time-Resolved Picosecond Photocurrents in Contacted Carbon Nanotubes, Leonhard Prechtel, Li Song, Stephan Manus, Dieter Schuh, Werner Wegscheider, Alexander W. Holleitner, Nano Letters 2011, 11 (1), pp 269,
DOI: 10.1021/nl1036897
Link: http://pubs.acs.org/doi/abs/10.1021/nl1036897

Other Headlines from Technische Universitaet Muenchen ...
 - Ultra fast photodetectors out of carbon nanotubes
 - How long does a tuning fork ring?
 - Relaxation leads to lower elasticity
 - New insights from the nano world: Direct observation of carbon monoxide binding
 - Electric current moves magnetic vortices

More Nanotubes Headlines ...
 - Free-standing single walled carbon nanotube thin films
 - Carbon Nanotubes Market - SWCNTs and MWCNTs Market Worth US$3.3 Billion by 2016 - Market Research
 - Bayer MaterialScience strengthens position in carbon nanotubes
 - New desalination process using carbon nanotubes
 - Rice University lab uses ruthenium complexes to dissolve nanotubes, add functionality


« Back To List »

« GET LISTED »
- submit company
- submit news
- submit events
- advertise here

« EVENTS »
- More Events


Copyright 2017 Nanotechwire.com | Privacy Policy |