First-principles simulation of Se and Te adsorbed on GaAs(001)

We have studied the adsorption of Se and Te on GaAs(001) using first-princi ples simulations. For each chalcogen species, 11 structures exhibiting 2 x 1 reconstruction with varying surface stoichiometry were simulated using a density functional formalism and pseudopotentials, thus yielding absolute s urface energies and detailed information about the; atomic positions, Our r esults are discussed in terms of a simple model for heteropolar surfaces an d compared to experimental results for these surfaces available from the li terature. [S0163-1829(99)07503-7].