Influence of In and As fluxes on growth of self-assembled InAs quantum dots on GaAs(0Â 0Â 1)

The growth of self-assembled (SA) quantum dots (QDs) on GaAs(0 0 1) by molecular beam epitaxy (MBE) is studied as a function of the In and As fluxes. Under growth rates below 0.05 ML/s, we find that the density of QDs increases not only with increasing In flux but also with As flux. The formation mechanisms are discussed based on the results obtained by atomic force microscopy (AFM), and that As flux alters the surface diffusion, leading to the control of QD nucleus density.