Details

Autor(en) / Beteiligte

• Lopes, E.M.
• Duarte, J.L.
• Dias, I.F.L.
• Laureto, E.
• Guimarães, P.S.S.
• Subtil, A.G.S.
• Quivy, A.A.

Titel

Magnetophotoluminescence study of GaAs/AlGaAs coupled double quantum wells with bimodal heterointerface roughness

Ist Teil von

• Journal of luminescence, 2012-05, Vol.132 (5), p.1183-1187

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2012

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• This work reports on the results of magnetophotoluminescence (MPL) measurements carried out in a sample containing two Al0.35Ga0.65As/GaAs, coupled double quantum wells (CDQWs), with inter-well barriers of different thicknesses, which have the heterointerfaces characterized by a distribution of bimodal roughness. The MPL measurements were performed at 4K, with magnetic fields applied parallel to the growth direction, and varying from 0 to 12T. The diamagnetic shift of the photoluminescence (PL) peaks is more sensitive to changes in the confinement potential, due to monolayer variations in the mini-well thickness, rather than to the exciton localization at the local potential fluctuations. As the magnetic field increases, the relative intensities of the two peaks in each PL band inverts, what is attributed to the reduction in the radiative lifetime of the delocalized excitons, which results in the radiative recombination, before the excitonic migration between the higher and lower energy regions in each CDQW occurs. The dependence of the full width at half maximum (FWHM) on magnetic field shows different behaviors for each PL peak, which are attributed to the different levels and correlation lengths of the potential fluctuations present in the regions associated with each recombination channel. ► Magnetophotoluminescence results from two coupled double quantum wells are reported. ► Each structure shows two emission channels due to bimodal heterointerface roughness. ► Little variations on thickness have greater effect than local potential fluctuations. ► With increasing B the excitonic migration changes between the bimodal regions. ► The FWHM depends on level and correlation length of the potential fluctuations.