Strong charge carrier confinement in purely strain induced GaAs/InAlAs single quantum wires

Abstract

We report on micro-photoluminescence studies of single quantum wires which were grown by molecular beam epitaxy. Employing the cleaved edge overgrowth technique, quantum wires located in an overgrown (011) oriented GaAs quantum well originate purely from the tensile strain field of InAlAs layers grown along the [100] direction. These stressor layers are separated by 1-µm-wide AlGaAs barriers so that the photoluminescence signals of different quantum wires can be resolved individually. Their confinement energy varies systematically with the widths of the stressor and overgrown layers, reaching values as high as 51.5 meV. The quantum wire signals are characterized by a smooth line shape even for the lowest excitation powers, indicating the absence of pronounced exciton localization.