Self-assembled InAs islands on GaAs(1̄1̄1̄) substrates

Characterization of InAs self-assembled islands, grown on GaAs(111)B by molecular beam epitaxy, is carried out by atomic force microscopy and photoluminescence spectroscopy for different growth conditions. Islands show lateral sizes ca 40 to 300 nm long by 30 nm wide. Narrow height distributions are achieved centered ca 4 or 20 nm, depending on the growth conditions. Samples with the taller islands show the stronger luminescence. The position of the peaks is surprisingly similar to those reported for self-assembled islands on GaAs(100), despite the differences on crystal orientation and island sizes. This results suggests that the photoluminescence observed for both (100) and (111) orientation is not determined by quantum size confinement in the islands.