Structure of the GaAs(110) surface in As-rich conditions

The dependence of the structure of the GaAs(110) surface on the As and Ga chemical potentials is explored. Total-energy calculations performed within the local-density-functional formalism using first-principles pseudopotentials indicate that in the extreme As-rich limit a 1×{}1 structure composed of As chains is slightly lower in energy than the Ga-As chain structure produced by cleaving. The 1×{}1 structure composed of Ga chains is found to be unstable with respect to Ga cluster formation. Calculations also indicate that the GaAs(110)1×{}1:Sb chain surface is stable with respect to Sb cluster formation.