Photoluminescence competition between confined states in delta doped AlGaAs/GaAs heterostructures
H. Ajlani1*, A. Meftah1, S. Aloulou1, R. Chtourou2, M. Oueslati1
1Unité de Recherche de Spectroscopie Raman, Département de Physique, Faculté des Sciences
de Tunis, 1060 Le Belvédère, Tunis, Tunisie
2Institut National de Recherche Scientifique et Technique, Tunis.
* Corresponding author. E-mail:firstname.lastname@example.org
Received: 05 April 2005; revised version accepted: 30 May 2005
Low temperature photoluminescence (PL) studies in n-type modulation doped GaAs/Al0.31Ga0.69As/GaAs:d Si/Al0.31Ga0.69As/GaAs heterostructures show a large asymmetric band located at energies higher than band-to-band radiative recombination energies in GaAs. We have combined experimental and theoretical modeling of the band structure and have shown that this band corresponds to radiative recombination of confined excitons in both asymmetric quantum well (AQW) in the GaAs channel and symmetric quantum well (SQW) in the barrier. The characteristics and the shape of the considered band have been studied as a function of excitation densityand temperature.
Keywords: Photoluminescence; AlGaAs; GaAs; Heterostructure; Quantum well.