Atomic structure of Ga and As atoms on GaAs(110)

Atomic structures of Ga and As atoms on GaAs(110) were examined employing a first-principles pseudopotential method. Both Ga and As atoms reside in the center of a triangle consisting of a surface Ga and two surface As atoms in the single-atom chemisorbed state. Adsorption energies for Ga and As atoms are 3.1 and 3.5 eV, respectively. Energy barrier heights of Ga and As atoms for the migration along the path through the interstitial channel were found to be 0.6 and 1.0 eV, respectively. Simulations on the deposition of two atoms reveal that a pair formation is stable against separate single-atom chemisorptions.