InAs and (In,Mn)As nanostructures grown on GaAs(1 0 0), (2 1 1)B, and (3 1 1)B substrates

InAs and (In,Mn)As nanostructures grown on GaAs(1 0 0), (2 1 1)B and (3 1 1)B substrates have been studied. Quantum dots (QDs) were observed when InAs was grown on GaAs(1 0 0) (or (3 1 1)B). QDs with bimodal size distribution were formed when InAs was deposited on GaAs(2 1 1)B at lower growth temperatures (" 4 ) whereas quantum dashes (QDHs) were observed at higher " 4 . (In,Mn)As QDs grown on GaAs(1 0 0) showed a broad range of dot sizes with irregular shape. (In,Mn)As QDs with bimodal size distribution were observed for the structure grown on GaAs(3 1 1)B. (In,Mn)As QDs grown on GaAs(2 1 1)B showed improved size uniformity compared to those grown on GaAs (1 0 0) and (3 1 1)B. The e!ects of Mn as a surfactant on InAs nanostructures were also studied. ( 1999 Elsevier Science B.V. All rights reserved.