Reaction path for Te during surfactant-mediated epitaxial growth of GaAs (100)

Using first-principles calculations and experimental evidence concerning the essential environment for surfactant-mediated epitaxial growth on the GaAs/Te~100! surface, we determine a short-ranged reaction path for the As↔Te exchange that is energetically favorable and prepares the surface for continued layer-by-layer growth. Furthermore, we explain the required partial coverage of the surfactant atoms as well as the required presence of both As and Ga adatoms.