Microstructural properties of closely stacked InAs quantum dots inserted in GaAs layers embedded in modulation-doped Al0.25Ga0.75As/GaAs heterostructures

Abstract

Coherent strained InAs quantum dot (QD) arrays embedded into undoped GaAs layers inserted in modulation-doped Al0.25Ga0.75As/GaAs heterostructures on GaAs (100) substrates were grown by molecular beam epitaxy. The microstructural properties of the InAs self-assembled QDs were investigated by using transmission electron microscopy (TEM) measurements. Thin InAs layers grown on GaAs substrates formed self-assembled InAs QDs vertically stacked along the growth direction. The TEM image showed that the self-assembled InAs QD arrays inserted in the GaAs These layers had no extended defects. The areal surface density of the QDs was 2.1 x 10(10) cm(-2). These results can help improve understanding of the microstructural properties of the InAs QD arrays embedded into GaAs layers inserted in AlxGa1-xAs/GaAs heterostructures.