Empty state and filled state image of ZnGa acceptor in GaAs studied by scanning tunneling microscopy

Abstract

ZnGa acceptor atoms in the first to sixth layer below the GaAs (110) cleavage plane have been identified. For the first time, we find that the empty state scanning tunneling microscopy image of a ZnGa acceptor is a characteristic equal latitude triangle-shaped feature of ∼4 nm width with a (110) mirror plane. The filled state image, however, is a spherical feature of similar size. These unique features can be used as the signature for the identification of ZnGa in GaAs.