Microcalorimetric absorption spectroscopy in GaN–AlGaN quantum wells

Axel Göldner (1) , Axel Hoffmann (1) , Bernard Gil (2) , Pierre Lefebvre (3) , Pierre Bigenwald (4) , Philippe Christol (4) , Hadis Morkoc (5)

1 Institut für Festkörperphysik
2 GES - Groupe d'étude des semiconducteurs
3 Institut de Photonique et d'Electronique Quantiques
4 AU - Avignon Université
5 Department of Electrical and Computer Engineering

Microcalorimetric measurements of small absorption coefficients have been performed on thin GaN–AlGaN quantum wells grown by Reactive Molecular Beam Epitaxy on Al 2O 3 substrates. In addition to strong absorption at the energy of the GaN buffer and at the energy of the thick AlGaN barrier layers, we could also readily detect transitions associated to the quantum well. These measurements which pave the way to a precise determination of the gap mismatch between the well and the barrier layers are combined with self consistent excitonic and envelope function calculations in the context of a model for the band line-ups which includes the piezoelectric effect.

Domaines: Electronique; Micro et nanotechnologies/Microélectronique

Axel Göldner, Axel Hoffmann, Bernard Gil, Pierre Lefebvre, Pierre Bigenwald, et al.. Microcalorimetric absorption spectroscopy in GaN–AlGaN quantum wells. European-MRS Spring Meeting - Symposium L : Nitrides and Related Wide Band Gap Materials, Jun 1998, Strasbourg, France. pp.319 - 322, ⟨10.1016/S0921-5107(98)00363-8⟩. ⟨hal-01756610⟩