Observation of film states and surface-state precursors for Ag films on Si(111)

Abstract
Ag films on Si(111)-(7×7) having thicknesses of 017 monolayers were studied with angle-resolved photoemission. The spectra exhibit quasiperiodic peaks with separations between neighboring peaks approximately proportional to the inverse of the film thickness. These are film states associated with the sp band of bulk Ag. A surface-state precursor was also observed on films as thin as two monolayers in thickness.