Magneto-optical properties of stacked self-assembled InAs quantum dots

Abstract

In this article, we report magneto-photoluminescence measurements on stacked self-assembled InAs quantum dots. By applying a magnetic field parallel to the growth direction, we determined the exciton reduced mass and exciton radius from the photoluminescence (PL) peak energy. We observed an asymmetric increase of the full width at half maximum of the quantum dots PL peak to the high-energy side that we associate to the size selectivity of the oscillator strength of the ground state transitions. The observed increase of the integrated intensity of the quantum dots line is explained in terms of the reabsorption of the photons emitted by the GaAs substrate and the InAs wetting layer. These effects are related to the multilayer structure of the sample.

Spectroscopy of sub-wetting layer states in InAs/GaAs quantum dot bi-layer systems

“…For example, recent magneto-optical studies of stacked self-assembled InAs QDs [33] have shown that the increase in the integrated intensity of the QD PL contribution in a magnetic field is completely compensated by the decrease in the integrated intensity of the GaAs and WL PL bands, thereby pointing to their inter-relation. In addition, systematic temperaturedependent measurements of PLE spectra from self-assembled InAs/GaAs QDs [34] present evidence for the interaction of discrete QD excited states with a quasi-continuum of states that spread just below the WL absorption edge.…”