Regensburg 2016 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 24: Carbon-based Nanostructures

HL 24.3: Vortrag

Dienstag, 8. März 2016, 10:00–10:15, H14

Picosecond photocurrents in single-walled carbon nanotubes — •Maximilian Engl, Christoph Karnetzky, and Alexander W. Holleitner — Walter-Schottky-Institute and Physics-Department, Technical University of Munich, Germany

The exciton dynamics in carbon nanotubes are typically detected in a time-resolved way by optical techniques such as the transient absorption technique and the time-resolved photoluminescence spectroscopy. Both methods focus mainly on the dynamics of localized charge carriers within the carbon nanotubes. Many questions remain concerning the separation and the transport of photogenerated charge carriers to source and drain leads in an optoelectronic device structure. We address these questions by an ultrafast photocurrent spectroscopy, which is based on an on-chip THz time domain spectroscopy [1]. We find a combination of an optically induced ultrafast displacement current and interband charge-carrier recombination processes to dominate the ultrafast photocurrent of the single-walled carbon nanotubes [2]. We further discuss inter-subband relaxation processes after the optical excitation [3].

We acknowledge financial support from the ERC-grant ”NanoREAL” and the DFG excellence cluster ”Nanosystems Initiative Munich” (NIM).

[1] L. Prechtel et al., Nature Communications, 3, 646, (2012).

[2] L. Prechtel et al., Nano Letters, 10, 1021, (2011).

[3] C. Karnetzky et al. (2016).