Observation of surface excitons in rare-gas solids

Abstract

Evidence is obtained for the excitation of surface excitons in solid Ar, Kr, and Xe in optical transmission and reflection experiments using synchrotron radiation. They are located at photon energies ranging from 0.6 eV for Ar to 0.1 eV for Xe below the corresponding bulk excitons excited from the valence bands. Their halfwidths (20-50 MeV) are less than half the values found for the bulk excitons. Some are split by an amount considerably smaller than the spin-orbit splitting of the valence bands. © 1976 The American Physical Society.