Empty Surface States, Image States, and Band Edge on Gold(111)

Inverse-photoemission observations on Au(111) reveal the n = 1 image stage, the L sub 1 (L exp + sub 6 ) band edge, and the continuation above the Fermi level E sub F of the well-established Shockley surface state. The image-state binding energy (0.60 plus /minus 0.05 eV) is lower than that obtained on Cu(111) or Ag(111), or that expected on the basis of elementary multiple-reflection theory (0.85 eV). The L sub 1 (L exp + sub 6 ) level is found to occur 3.6 plus/minus 0.1 eV above E sub F . 32 ref.--AA