Delocalization effects at metal-semiconductor interfaces

Changes with onset of metallic behavior in the position of an impurity-stabilized Fermi level at the GaAs-Ag interface are interpreted in a model based on delocalization of the impurity levels. The resulting energy broadening of interface states appears to be an important mechanism underlying the Schottky behavior; in particular the model obviates the need for separate donor or acceptor properties of the impurity levels. © 1988 The American Physical Society.