Shape transition of coherent three-dimensional (In,Ga)As islands on GaAs(100)

Abstract

The shape transition of coherent three-dimensional (3D) islands is observed experimentally in the (In,Ga)As/GaAs(100) material system. In the molecular-beam epitaxy of a 1.8-nm-thick In0.35Ga0.65As single layer, we find that the shape of the coherent 3D islands transforms from round to elongated when increasing the growth temperature. A quantitative agreement of our experimental data with the theoretical work of Tersoff and Tromp is achieved.