Effect of the dimer structure on indium adsorption and diffusion on a GaSb surface

The adsorption properties and surface diffusion of an indium adatom on a GaSb(001)‐(2 × 3) structure have been studied using first‐principles calculations. We find that the indium adatoms are preferentially adsorbed in the low energy trenches along the [110] direction at bridge positions of surface dimers. Besides, the adsorption sites connecting these trenches along [110] present distinct properties for different surface dimer structures. For the structure with Sb–Sb homodimers, the dimer arrangement reduces significantly the adatom diffusion barrier along the [110] direction and the calculations on diffusion coefficients demonstrate that [110] is the fast diffusion direction. While on the structure with Ga–Sb heterodimers, the adsorption sites are separated by the heterodimers causing a considerable diffusion barrier and [ $ \bar 1 $ 10] becomes the fast diffusion direction accordingly. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)