Resonant Raman scattering in GaAsN : Mixing, localization and band impurity formation of electronic states Article - 2003

Guillaume Bachelier, Adnen Mlayah, M. Cazayous, Jesse Groenen, Antoine Zwick, Hélène Carrère, Eléna Bedel-Pereira, Alexandre Arnoult, A. Rocher, Anne Ponchet

Guillaume Bachelier, Adnen Mlayah, M. Cazayous, Jesse Groenen, Antoine Zwick, Hélène Carrère, Eléna Bedel-Pereira, Alexandre Arnoult, A. Rocher, Anne Ponchet, « Resonant Raman scattering in GaAsN : Mixing, localization and band impurity formation of electronic states  », Physical Review B : Condensed Matter and Materials Physics (1998-2015), 2003, p. 205325. ISSN 1098-0121

Abstract

Raman measurements on a thick GaAsN layer and on GaAsN/GaAs quantum well structures are reported. The scattering was excited close to resonance with the N-induced E+ transition, and detected in both Stokes and anti-Stokes regions including the low-frequency range around the Rayleigh line. A broad continuous scattering due to acoustic phonons is observed on the thick GaAsN layer. Calculations of the Raman efficiency showed that localization and mixing of the resonant electronic states well account for the measured spectral lineshapes. The localization length around a single nitrogen impurity is estimated and the band impurity formation discussed. Periodic oscillations of the scattered intensity are clearly observed on the quantum well structures. They are analyzed in terms of Raman interference effects due to spatial coherence of the resonant electronic states. We found that layering of the electronic density along the growth axis well accounts for the observed oscillations period, spectral envelope and interference contrast. The experimental data and the calculations support the formation of an impurity band.

Voir la notice complète sur HAL

Actualités