Regensburg 2004 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 15: Photonische Kristalle III
HL 15.12: Vortrag
Dienstag, 9. März 2004, 13:00–13:15, H17
Highly emissive rod-like colloidal nanocrystals as novel polarized light-sources — •J. Müller1, D. Talapin2, F. Saas1, W. Manfred1, A.L. Rogach1, J.M. Lupton1, J. Feldmann1, and H. Weller2 — 1Photonics and Optoelectronics Group, Sektion Physik, LMU Munich, 80799 Munich, Germany — 2Institute of Physical Chemistry, University of Hamburg, 20146 Hamburg, Germany
The use of single semiconductor nanocrystals as light-emitting probes of the dielectric and photonic environment is limited by their blinking behaviour. We present a new kind of material which consists of a spherical CdSe core, surrounded by an elongated CdS shell. These structures are found to exhibit exceptional stability in single particle experiments. Unlike most colloidal nanocrystals, we observe temporally constant emission, i. e. a virtual absence of characteristic blinking behaviour. The emission is linearly polarised along the long axis of the crystal. The particles have fluorescence quantum yields in excess of 70 % and very large absorption cross sections, which give rise to an exceptionally high fluorescence intensity (Talapin et al., Nano Lett. 2003). This allows us to record single particle emission spectra in as little as 10 ms, which reveal narrow fluorescence lines with widths of down to 0.1 nm at low temperatures. The high stability and brightness suggest that these particles are ideally suited as nanoscale probes of the photonic density of states in photonic crystals.