Holography of Ge(111)-[ital c](2[times]8) by surface core-level photoemission

Energy-extended photoelectron holography has been applied for the first time to image surface structure using intrinsic surface core-level shifts. The Ge(111)-[ital c](2[times]8) 3[ital d] core level exhibits a surface component shifted by 0.8 eV relative to the bulk. Angle-resolved photoemission from this so-called [ital S]2 component shows intensity oscillations as a function of photon energy. Inversion of the data collected at many emission angles yields a three-dimensional image of the nearby atoms, showing conclusively that the [ital S]2 emission is due to adatoms bonded in [ital T][sub 4] sites.