Highly Photo-Excited Nitride Quantum Wells: Threshold for Exciton Bleaching

Philippe Christol (1) , P. Bigenwald , A. Kavokin (2) , B. Gil (3) , P. Lefebvre (3)

1 Laboratoire de Physique des Matériaux
2 Marie-Curie Chair of Excellence "Polariton Devices"
3 GES - Groupe d'étude des semiconducteurs

We combined the self-consistent procedure of solving the SchroÈ dinger and Poisson equations for belectron and hole wave functions with the variational calculation of exciton states in strained GaN/AlGaN quantum wells. The procedure accounted properly for the free-carrier effects on the excitonic wave function, namely, bleaching and quantum exclusion effects and allowed to quantify the dependence of the exciton energy and oscillator strength on the optical pumping density. The calculation revealed an interesting interplay between the screening of the polarisation fields which leads to the increase of the electron±hole overlap and the screening of the electron±hole interaction which affects the exciton Bohr radius. Peculiar non-monotonic behaviour of the exciton binding energy as function of the density of electron±hole plasma results from these effects.

Domaines: Electronique; Micro et nanotechnologies/Microélectronique

Philippe Christol, P. Bigenwald, A. Kavokin, B. Gil, P. Lefebvre. Highly Photo-Excited Nitride Quantum Wells: Threshold for Exciton Bleaching. 3rd International Conference on Nitride Semiconductors, Bernard GIL; Pierre LEFEBVRE, Jul 1999, Montpellier (FR), France. pp.481 - 486, ⟨10.1002/(SICI)1521-3951(199911)216:1<481::AID-PSSB481>3.0.CO;2-K⟩. ⟨hal-01756604⟩