MICROSCOPIC-SCALE LATERAL INHOMOGENEITIES OF THE SCHOTTKY-BARRIER-FORMATION PROCESS

The interpretation of photoemission-spectromicroscopy studies of Au on GaSe requires a revision of established ideas about this interface, which has long been considered a prototype of Schottky-like systems. We find that the interface-formation process involves strong substrate-overlayer interactions, the release of free Ga, and the formation of interface species, and leads to a barrier height in total disagreement with the Schottky model. Furthermore, the space-resolving capabilities of our instruments revealed lateral inhomogeneities of the local overlayer thickness and of the local band bending.