Structural atomic-scale analysis of GaAs/AlGaAs quantum wires and quantum dots grown by droplet epitaxy on a (311)A substrate

We report the structural analysis at the atomic scale of GaAs/AlGaAs quantum wires and quantum dots grown by droplet epitaxy on a (311)A-oriented substrate. The shape, interfaces, and composition of these nanostructures and their surrounding matrix are investigated. We show that quantum wires can be created by annealing uncapped quantum dots. Substantial interface fluctuations, attributed to interface instability induced by the liquid Ga droplet, are observed. Despite the interface fluctuations, no intermixing of Al was found in either the quantum wires or quantum dots. A wetting layer connecting the quantum dots could not be observed