Electronic states of metal atoms on the GaAs(110) surface studied by scanning tunneling microscopy

Using the scanning tunneling microscope, Au adsorbates are found to bond to Ga atoms on the GaAs(110) surface. A characteristic spectrum of band-gap states is observed for the Au adsorbates. Both donor and acceptor states are seen, and they are identified with the first and second electron states of the Au-Ga bond, respectively. © 1989 The American Physical Society.