SELF-ASSEMBLED INAS ISLANDS ON GAAS((111)OVER-BAR) SUBSTRATES

Characterization of InAs self-assembled islands, grown on GaAs(111)B b y molecular beam epitaxy, is carried out by atomic force microscopy an d photoluminescence spectroscopy for different growth conditions. Isla nds show lateral sizes ca 40 to 300 nm long by 30 nm wide. Narrow heig ht 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 tho se reported for self-assembled islands on GaAs(100), despite the diffe rences on crystal orientation and island sizes. This results suggests that the photoluminescence observed for both (100) and (111) orientati on is not determined by quantum size confinement in the islands. (C) 1 997 Elsevier Science B.V.