Regensburg 2007 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 28: Optical properties

HL 28.3: Talk

Wednesday, March 28, 2007, 14:45–15:00, H14

Microscopic investigations of luminescence from multiple quantum-well structures — •Marco Werchner, Martin Schafer, Walter Hoyer, Mackillo Kira, and Stephan W. Koch — Department of Physics and Material Sciences Center, Philipps-University, Renthof 5, D-35032 Marburg, Germany

Multiple quantum-well (QW) structures provide one-dimensional realizations of resonant photonic crystals where the periodic arrangement of emitters can drastically influence the photonic modes. As a consequence, luminescence from multiple QWs can be considerably different from the single QW case. The theoretical modeling of such non-classical light emission of multiple QWs requires a consistent treatment by a microscopic theory for the quantum-well electrons and the quantized light field.

It is shown that the radiative coupling between the periodically spaced QWs yields a strong reduction of the normalized light emission. This incoherent subradiant effect is shown to increase with increasing QW number. It is present for all QW spacings but strongest for Bragg structures. Clearly, the suppression of the radiative decay results in an enhancement of the exciton lifetime. Moreover, the direct creation of ground-state excitons is shown to be possible via the radiative coupling between the QWs.