MAGNETO-LUMINESCENCE OF A SINGLE LATERAL ISLAND FORMED IN A TYPE - Ⅱ GaAs/AlAs QW

摘要

Ensembles of sharp emission lines present in the macro-luminescence of type-Ⅱ GaAs/AlAs double quantum well structures were studied. Micro-luminescence experiments allowed us to conclude that the sharp emission lines originate from lateral GaAlAs islands of a few μm in diameter, formed in the structure. They serve as efficient type-Ⅰ recombination centers for indirect excitons and/or carriers diffusing in the GaAs/AlAs QW structure. Magneto-luminescence spectra from single islands resemble those observed for natural quantum dots formed in narrow GaAs quantum wells. The observed emission is assigned to the recombination of neutral excitons as well as excitonic molecules.