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HL: Halbleiterphysik
HL 49: Poster II
HL 49.67: Poster
Donnerstag, 27. März 2003, 16:30–19:00, HSZ/P2
Temperature-dependence of the exciton emission in single — •Matthias Schwab, Gerhard Ortner, and Manfred Bayer — Experimentelle Physik II, Universität
Considerable interest has been focused on quantum dot (QD) structures in the last few years. These structures are possible candidates in the field of quantum information processing.
We have performed optical studies of In0.60Ga0.40As/GaAs and InAs/GaAs QD’s. The samples were covered with a global Al-mask containing small holes allowing us to address single QD’s and simultaneously to apply electric fields. The samples have been mounted on the cold-finger of a He-flow-cryostat with the possibility to vary the sample temperature. We have measured the redshift of the exciton emission in both sample types up to 120 K. The redshift is in good agreement with calculations of these structures [1] and shows a relatively weak dependence in the cryogenic region. For the temperature range up to 50 K we have investigated the E-field dependence of the linewidth Γ, which can be approximated by Γ=α T + Γ0. Due to piezoelectric coupling Γ shows a strong dependence to the applied electric field.
[1] R. Pässler, PRB 66, 2002