Carrier dynamics in InAs/AlAs quantum dots: lack in carrier transfer from wetting layer toquantum dots

Abstract

Structures with self-assembled InAs quantum dots (QDs) embedded in an AlAsmatrix have been studied by steady-state and transient photoluminescence. Ithas been shown that in contrast to InAs/GaAs QD systems carriers are mainlycaptured by quantum dots directly from the AlAs matrix, while transfer of carrierscaptured by the wetting layer far away from QDs to the QDs is suppressed. At lowtemperatures the carriers captured by the wetting layer are localized by potentialfluctuations at the wetting layer interface, while at high temperatures the carriers aredelocalized but captured by nonradiative centers located in the wetting layer.