Dresden 2011 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 4: Carbon: Diamond, Nanotubes, and Graphene

HL 4.7: Talk

Monday, March 14, 2011, 12:00–12:15, POT 251

Time-resolved picosecond photocurrents in contacted carbon nanotubes — •Leonhard Prechtel¹, Li Song², Stephan Manus², Dieter Schuh³, Werner Wegscheider⁴, Nadine Erhard¹, and Alex W. Holleitner¹ — ¹Walter Schottky Institut and Physik-Department, TU München — ²Fakultät für Physik and Center for NanoScience (CeNS), LMU, München — ³Institut für Experimentelle und Angewandte Physik, Universität Regensburg — ⁴Laboratorium für Festkörperphysik, ETH Zürich

We introduce coplanar stripline circuits to resolve the ultrafast photocurrent dynamics of freely suspended carbon nanotubes (CNTs) in the time-domain. By applying an on-chip pump-probe laser spectroscopy we demonstrate that CNTs, contacted by metal electrodes, exhibit a picosecond photocurrent response. We find a combination of an optically induced ultrafast displacement current, transport of photo-generated charge-carriers at the Fermi velocity to the electrodes, and interband charge-carrier recombination processes to dominate the ultrafast photocurrent of the CNTs.