# Dresden 2006 – wissenschaftliches Programm

## Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

# HL: Halbleiterphysik

## HL 52: Quantum dots and wires: Optical properties IV

### HL 52.7: Vortrag

### Freitag, 31. März 2006, 12:30–12:45, POT 151

**Demonstration of intrinsic non-exponential quantum dot emission dynamics due to reduced electron-hole correlation** — •Thomas Auer^{1}, Matthias Schwab^{1}, Manfred Bayer^{1}, Thorsten Berstermann^{1}, Jan Wiersig^{2}, Norman Baer^{2}, Christopher Gies^{2}, Frank Jahnke^{2}, Viktorina Stavarache^{3}, Dirk Reuter^{3}, and Andreas Wieck^{3} — ^{1}Experimentelle Physik II, Universität Dortmund, 44221 Dortmund — ^{2}Institut für Theoretische Physik, Universität Bremen, 28334 Bremen — ^{3}Angewandte Festkörperphysik, Ruhr-Universität Bochum, 44780 Bochum

The emission dynamics of self-assembled quantum dots has been studied using time-resolved photoluminescence (TRPL) spectroscopy. Quantum dot emission dynamics are normally described using the picture of quantum dots as two-level systems, where electron-hole-pairs are fully correlated, resulting in a predicted exponential decrease of the emission. Non-exponential decay of the TRPL has been reported in the literature, but is normally attributed to various factors, such as dark excitons or ensemble variations. However our calculations show that reduction of e-h pair correlation leads to intrinsically non-exponential dynamics. In agreement with these calculations, our measurements of the radiative exciton decay clearly show a non-exponential behaviour with non-resonant excitation. A study of the temperature dependence of the decay and comparison with measurements on n-doped quantum dots reveal the intrinsic nature of the non-exponentiality. By exciting resonantly, a fully correlated two-level system may be prepared which displays an exponential decay as expected.