Interference between Bulk and Surface Photoemission Transitions in Ag(111)

Abstract

The direct-transition photoemission peak from the sp valence band of Ag(111) shows a pronounced asymmetry. The emission intensity on the lower binding energy side of this peak is considerably higher, and extends to a cutoff at the band edge just below the Fermi level. This extra emission is derived from indirect transitions induced by the surface. A linear combination of the direct (bulk) and indirect (surface) channels results in the asymmetric line shape.