Regensburg 2004 – scientific programme
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HL: Halbleiterphysik
HL 12: Poster I
HL 12.92: Poster
Monday, March 8, 2004, 16:30–19:00, Poster A
The Correlation between Emission Spectra and Atomic Scale Structure of GaAs/AlGaAs Quantum Wells — •M. Erdmann1, C. Ropers1, M. Wenderoth1, L. Winking1, T. C. G. Reusch1, R. G. Ulbrich1, S. Malzer2, and G. Döhler2 — 1IV. Physikalisches Institut der Universität Göttingen, Tammannstraße 1, 37077 Göttingen — 2Inst. für techn. Physik, Universität Erlangen-Nürnberg, Erwin-Rommel-Straße 1, 91058 Erlangen
We have performed cross-sectional Scanning Tunneling Microscopy and Micro-Photoluminescence experiments on GaAs/AlGaAs quantum wells and correlated the structural and optical data. The emission spectra were obtained using a scanning Micro-PL microscope with lateral resolution of 500 nm. Large X-STM topographs with atomic resolution were converted into potentials by linear scaling, serving as starting point for a numerical simulation in Envelope Function approximation of the optical spectra of the studied real structure. We assume a laterally isotropic aluminium distribution and use a model recently introduced by Runge and Zimmermann [2]. In real quantum films, interface fluctuations lead to localization of excitons in the disorder potential of the quantum well interfaces [1]. The resulting inhomogeneous broadening of the optical spectra is quantitatively reproduced by the simulated spectra [3].
[1] A. Zrenner et al., Phys. Rev. Lett. 72 (1994) 3382
[2] R. Zimmermann, F. Große, and E. Runge, Pure Appl. Chem. 69 (1997) 1179
[3] C. Ropers, M. Wenderoth, L. Winking, T.C.G. Reusch, M. Erdmann, R.G. Ulbrich, S. Malzer and G. Döhler, Phys. Rev. Lett. (submitted)