Excitons and biexcitons in MOVPE-grown ZnS epitaxial layers

High quality MOVPE-grown ZnS GaAs epilayers are characterized by reflection, transmission and linear photoluminescence (PL) spectroscopy at 2 K. The GaAs substrate of a part of each ZnS layer is removed and the optical properties of as-grown and etched surfaces are compared. The splitting (caused by...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Solid state communications 1995, Vol.96 (9), p.637-643
Hauptverfasser: Guennani, D, Valenta, J, Manar, A, Grun, J.B, Cloitre, T, Briot, O, Aulombard, R.L
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:High quality MOVPE-grown ZnS GaAs epilayers are characterized by reflection, transmission and linear photoluminescence (PL) spectroscopy at 2 K. The GaAs substrate of a part of each ZnS layer is removed and the optical properties of as-grown and etched surfaces are compared. The splitting (caused by the thermally induced strain) of the topmost Γ 8 valence band into the heavy and light-hole subbands ( Δ hl=4 meV) and the transitions involving exciton ground and excited states are better seen in PL excitation spectra than in ordinary PL spectra. From the analysis of the nonlinear PL and PL excitation spectra, we can conclude the existence of biexcitons with a binding energy of about 10 to 12 meV under an intermediate intensity of excitation (a density of about 2.5×10 16 to 2.5×10 17 e-h excited pairs per cm 3).
ISSN:0038-1098
1879-2766
DOI:10.1016/0038-1098(95)00539-0