Dresden 2006 – scientific programme

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HL: Halbleiterphysik

HL 50: Poster II

HL 50.94: Poster

Thursday, March 30, 2006, 16:30–19:00, P3

Highly resonant Raman spectroscopy of InAs quantum dots — •Tim Köppen, Thomas Brocke, Tobias Kipp, Andreas Schramm, Christian Heyn, and Detlef Heitmann — Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung der Universität Hamburg, Jungiusstraße 11, 20355 Hamburg, Germany

We investigate the electronic properties of InAs quantum dots grown with Indium flush technique [1] using resonant inelastic light scattering. These quantum dots allow for highly resonant excitation with near-infrared laser light near the E₀ gap. Photoluminescence measurements show this gap to be at approximately 1.2 eV. In previous Raman experiments on InAs quantum dots grown without flush technique we used the E₀ + Δ gap (∼ 1.65 eV) for resonant excitation [2]. With technical improvements and the stronger resonance we get an increase in the electronic Raman signal of a factor of ∼ 250. We now observe signatures of single quantum dots in our spectra.

This project is supported by the Deutsche Forschungsgemeinschaft via SFB 508 “Quantenmaterialien".

[1] S. Fafard et al., Phys. Rev. B 59, 15368

[2] T. Brocke et al., Phys. Rev. Lett. 91, 257401