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Light‐Hole and Heavy‐Hole Excitons: the Right Probe for the Physics of Low N Content GaAsN
Author(s) -
Taliercio T.,
Gil B.,
Lefebvre P.,
Pinault M.A.,
Tournié E.
Publication year - 2002
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(200212)234:3<778::aid-pssb778>3.0.co;2-h
Subject(s) - transmittance , exciton , valence (chemistry) , valence band , ground state , lattice (music) , materials science , condensed matter physics , physics , atomic physics , band gap , optoelectronics , quantum mechanics , acoustics
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.