11-02/03 :: February / March 2011

nanotimes News in Brief

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A team of researchers headed by Professor Ale-

xander Holleitner, a physicist at the Technical University Munich, Germany, and member of the Cluster of Excellence Nanosystems Munich (NIM), has now succeeded in developing a measurement method allow- ing a time- based reso- lution of the so-called photocurrent in photodetectors with picosecond precision.

Computer simulations show deformations in the crystal lattice of Rare Earths. Thereby the use of these special materials can be optimised. © Thomas Schrefl / FWF

At the heart of the photodetectors in question are carbon tubes with a diameter of about one nano- meter spanning a tiny gap between two gold de- tectors. The physicists measured the speed of the electrons by means of a special time-resolved laser spectroscopy process – the pump-probe tech- nique. 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.

Contact: Prof. Dr. Thomas Schrefl, St. Pölten University of Applied Sciences, Matthias Corvinus-Str. 15, 3100 St. Pöl- ten, Austria, Phone +43 / 2742 / 313 228 - 313: http://www.fhstp.ac.at

Austrian Science Fund (FWF), Mag. Stefan Bernhardt, Haus der Forschung, Sensengasse 1, 1090 Vienna, Austria, Phone +43 / 1 / 505 67 40 - 8111

Leonhard Prechtel, Li Song, Stephan Manus, Dieter Schuh, Werner Wegscheider, Alexander W. Holleitner: Time-Resolved Picosecond Photocurrents in Contacted Carbon Nanotubes, Nano Letters, Volume 11(2011), Is- sue 1, January 12, 2011, Pages 269-272, DOI:10.1021/ nl1036897: http://dx.doi.org/10.1021/nl1036897

Image: Carbon nanotubes bridging two gold electrodes, © TUM