Polarization anisotropy of stacked InAs quantum dots on InGaAs/GaAs cross-hatch patterns

Abstract

Stacked InAs quantum dots (QDs) are grown on InGaAs/GaAs cross-hatch patterns (CHPs) by molecular beam epitaxy. The QDs, found almost exclusively on the cross-hatches, have greater lateral aspect ratio and are taller than typical QDs on flat surfaces. Polarization-resolved photoluminescent measurements show that both the QDs and CHPs exhibit polarization anisotropy. But while the CHP-related anisotropy is constant, the QD-related anisotropy is significantly enhanced or suppressed as the aspect ratio and height of the QD ensemble vary with the number of stacks. The polarization anisotropy observed agrees well with multiband tight-binding theoretical calculations of interband polarization in InAs/GaAs QDs.