Crystallographic anisotropy in InAs quantum dashes on GaAs

In this presentation, we will discuss data resulting from high-resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM) and photoluminescence studies comparing QDs to Qdashes. Both structures are grown on GaAs substrates using InAs coverage on a thin In/sub x/Ga/sub 1-x/As layer. Both structures include an AlGaAsSb metamorphic buffer to grade the lattice constant from the GaAs substrate to the InGaAs matrix. HRTEM images of a Qdash cleaved along the [110] and [1-10] crystal plane, respectively. The lattice constant is determined from the images and compared.