Surface atomic structure and bonding of GaAs(110)-p(1×1)–Bi (1 ML)

Abstract

The surface atomic and electronic structure of GaAs(110)‐p(1×1)–Bi (1 ML) has been examined using a tight‐binding total‐energy (TBTE) model. Two structural candidates were considered; the epitaxial continued‐layer structure (ECLS) and the epitaxial on‐top structure (EOTS). The TBTE computations indicate that the ECLS is more stable than the EOTS by ∼0.06 eV/surface atom/unit cell in agreement with a recent low‐energy electron diffraction (LEED) intensity analysis which selected the ECLS as the best‐fit structure. The predicted TBTE structural parameters for the ECLS are in good agreement with the best‐fit LEED results. The energy difference between the ECLS and EOTS is much smaller for the Bi/GaAs interface than for the Sb/GaAs interface (∼0.11 eV/surface atom/unit cell) in agreement with the proposition that the relative stability of the ECLS and EOTS is a function of the overlayer‐substrate mismatch; with the EOTS being favored for larger overlayer‐substrate mismatch. The primary difference between the ...