Regensburg 2007 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 27: INTERNAL SYMPOSIUM Optical Spectroscopy II
CPP 27.7: Hauptvortrag
Donnerstag, 29. März 2007, 16:30–17:00, H40
Optical spectroscopy on single carbon nanotubes — •Achim Hartschuh1, Huihong Qian1, Tobias Gokus1, Mathias Steiner2, and Alfred Meixner2 — 1Department Chemie und Biochemie and CeNS, LMU Muenchen, Germany — 2Institut fuer Physikalische und Theoretische Chemie, Universitaet Tuebingen, Germany
Semiconducting single-walled carbon nanotubes (SWNTs) are photoluminescent quasi-one-dimensional quantum wires with great promise for applications in photonics, nanoelectronics and optical sensing. Light emission from SWNTs is dominated by excitonic recombination with a low quantum yield of typically 10e-3 for embedded nanotubes. Recent measurements on single nanotubes using confocal Raman and photoluminescence microscopy revealed variations of both emission energies and excited-state lifetimes from nanotube to nanotube [1, 2]. Lifetime variations appear to result from defect mediated non-radiative transitions to non-luminescent states while energetic variations can be attributed to fluctuations in the dielectric environment of the nanotube. Since nanotubes consist of surface atoms only, dielectric screening and thus the emission energy of excitonic states are highly susceptible to the local environment making them ideally suited as nanoscale optical sensors (see e.g. [3]).
[1] A. Hartschuh et al., Science 301, 1293 (2003). [2] A. Hagen et al., Phys. Rev. Lett. 95, 197401 (2005). [3] D. A. Heller et al., Science 311, 508 (2006).