Light-sensitive electron-loss measurements on clean and oxygen-adsorbed amorphous silicon

Abstract

We have observed light‐sensitive oxygen‐induced low‐energy electron losses at amorphous silicon surfaces at 7.6, 10.1, and 12.9 eV. The crucial feature of our interpretation is the requirement that surface states in the band gap, isolated from the valence and conduction bands, must be involved in the loss transitions. An energy‐level scheme, based on the above requirement and on the valence‐ and conduction‐band structure determined by others, can readily account for the observed loss transitions and their light sensitivity.