SIGNATURES OF BULK AND SURFACE ARSENIC ANTISITE DEFECTS IN GAAS(100)

Scanning tunneling microscopy (STM) has recently been used in the study of bulk arsenic antisite defects in GaAs. In this work, we report extensive theoretical calculations of such defects in the vicinity of a GaAs(110) surface, which provide essential information for the interpretation of experiments. Defects display remarkably distinct properties depending on whether they are fourfold or threefold coordinated. The nature of ''satellite peaks'' observed in experiment is elucidated. We predict the conditions under which STM-measured properties will be faithful to the properties of the bulk defect.