Self-assembly of GaAs quantum wires grown on (311)A substrates by droplet epitaxy

We report the formation of GaAs quantum wires (QWRs) on (311)A substrates by droplet epitaxy. High-density quantum dots coalesce to form wires oriented along the [233] direction as a result of atom diffusion triggered by thermal annealing. Luminescence from the QWRs is significantly polarized parallel to the wire direction, which would result in higher gain in lasers that use cleaved (011) surfaces as Fabry–Pérot mirrors. Lasing is obtained for a GaAs/AlGaAs QWR laser diode with fivefold-stacked QWR layers under pulsed operation at a low temperature