OPTICAL INVESTIGATION OF MBE OVERGROWN INGAAS/GAAS WIRES

We have prepared buried InGaAs/GaAs wires by MBE overgrowth of wet etched wires with widths down to 40 nm. The overgrown structures show a good surface morphology and good luminescence properties. In contrast to the monotonous decrease of the emission intensity with decreasing wire widths, observed for etched only structures, we observe an increase of the emission intensity in the overgrown wires. This effect is correlated with the passivation of surface recombination centres by the overgrowth and an efficient carrier capture into the wires after overgrowth.