Light-Hole and Heavy-Hole Excitons: the Right Probe for the Physics of Low N Content GaAsN

Thierry Taliercio (1) , Bernard Gil (1) , Pierre Lefebvre (1) , Marie-Amandine Pinault (2) , Eric Tournié (2)

1 GES - Groupe d'étude des semiconducteurs
2 CRHEA - Centre de recherche sur l'hétéroepitaxie et ses applications

We have performed transmittance and piezomodulated transmittance measurements of as-grown GaAsN layers on GaAs substrates. The absorption shows energy an splitting of the ground state transition and a simultaneous increase of the splitting with the increase of the N content. This indicates the presence of a strain, which lifts the light- and heavy-hole valence band degeneracy. Surprisingly the piezomodulated transmittance shows that the heavy-hole exciton is the ground state! This implies that the GaAsN layers have a lattice parameter larger than that of GaAs and are under compression. The origin of the lattice parameter increase is the incorporation of N atoms on interstitial sites.

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

Thierry Taliercio, Bernard Gil, Pierre Lefebvre, Marie-Amandine Pinault, Eric Tournié. Light-Hole and Heavy-Hole Excitons: the Right Probe for the Physics of Low N Content GaAsN. International Workshop on Nitride Semiconductors (IWN 2002), Jul 2002, Aix-la-Chapelle, Germany. pp.778-781, ⟨10.1002/1521-3951(200212)234:3<778::AID-PSSB778>3.0.CO;2-H⟩. ⟨hal-01319577⟩