Optical studies of ultrashort-period GaAs/AlAs superlattices grown on (In,Ga)As pseudosubstrate.

Mohammed Rezki (1) , A.M. Vasson (1) , Aime Vasson (1) , Pierre Lefebvre (2) , Vincent Calvo (2) , Planel Richard (3) , Gilles Patriarche (3)

1 LASMEA - Laboratoire des sciences et matériaux pour l'électronique et d'automatique
2 GES - Groupe d'étude des semiconducteurs
3 L2M - Laboratoire de Microstructures et de Microélectronique

We present studies of GaAs/AlAs ultrashort-period superlattices grown on (In,Ga)As pseudosubstrates. Piezomodulation spectroscopy is used for the identification of conduction- and valence-band states involved in optical transitions. This study shows how the lattice mismatch between AlAs and (In,Ga)As can be exploited for the unconditional obtaining of pseudodirect GaAs/AlAs superlattices, with a ground conduction subband of Xz symmetry. It is shown that GaAs/AlAs superlattices, with ultrashort periods (2–8 monolayers), which are indirect when grown on GaAs substrate, become pseudodirect when grown on (In,Ga)As pseudosubstrate. In addition, the first quantized light-hole subband is found to be the ground valence-band state, in good agreement with envelope-function calculations including the coupling between light-hole and spin-orbit split-off bands.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Optique [physics.optics]; Micro et nanotechnologies/Microélectronique; Optique / photonique

Mohammed Rezki, A.M. Vasson, Aime Vasson, Pierre Lefebvre, Vincent Calvo, et al.. Optical studies of ultrashort-period GaAs/AlAs superlattices grown on (In,Ga)As pseudosubstrate.. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 1998, 58 (12), pp.R7540. ⟨10.1103/PhysRevB.58.R7540⟩. ⟨hal-01288966⟩